Web21/09/ · Generally, a download manager enables downloading of large files or multiples files in one session. Many web browsers, such as Internet Explorer 9, include a download manager WebThis option creates a single longer image, by joining all the current images in sequence top-to-bottom. Use +append to stack images left-to-right. If they are not of the same width, narrower images are padded with the current -background color setting, and their position relative to each other can be controlled by the current -gravity setting WebDouble-precision floating-point format (sometimes called FP64 or float64) is a floating-point number format, usually occupying 64 bits in computer memory; it represents a wide dynamic range of numeric values by using a floating radix point.. Floating point is used to represent fractional values, or when a wider range is needed than is provided by fixed Web14/12/ · You can find out more about how these types are encoded when you serialize your message in Protocol Buffer Encoding.  Kotlin uses the corresponding types from Java, even for unsigned types, to ensure compatibility in mixed Java/Kotlin codebases.  In Java, unsigned bit and bit integers are represented using their signed WebApple Footer The following purchases with Apple Card are ineligible to earn 5% back: monthly financing through Apple Card Monthly Installments, Apple iPhone Payments, the iPhone Upgrade Program, and wireless carrier financing plans; Apple Media Services; AppleCare+ monthly payments. Subject to credit approval. Valid only on qualifying ... read more
See the -annotate option for another convenient way to annotate an image with text. The rotate primitive rotates subsequent shape primitives and text primitives about the origin of the main image:. The skewX and skewY primitives skew them with respect to the origin of the main image or the region. The transformations modify the current affine matrix, which is initialized from the initial affine matrix defined by the -affine option.
Transformations are cumulative within the -draw option. The initial affine matrix is not affected; that matrix is only changed by the appearance of another -affine option.
If another -draw option appears, the current affine matrix is reinitialized from the initial affine matrix. Use the color primitive to change the color of a pixel to the fill color see -fill.
Follow the pixel coordinate with a method:. Consider the target pixel as that specified by your coordinate. The point method recolors the target pixel. The replace method recolors any pixel that matches the color of the target pixel.
Floodfill recolors any pixel that matches the color of the target pixel and is a neighbor, whereas filltoborder recolors any neighbor pixel that is not the border color.
Finally, reset recolors all pixels. Use matte to the change the pixel matte value to transparent. Follow the pixel coordinate with a method see the color primitive for a description of methods. The point method changes the matte value of the target pixel. The replace method changes the matte value of any pixel that matches the color of the target pixel. Floodfill changes the matte value of any pixel that matches the color of the target pixel and is a neighbor, whereas filltoborder changes the matte value of any neighbor pixel that is not the border color -bordercolor.
Finally reset changes the matte value of all pixels. You can set the primitive color, font, and font bounding box color with -fill , -font , and -box respectively.
Options are processed in command line order so be sure to use these options before the -draw option. Drawing primitives conform to the Magick Vector Graphics format. Note, drawing requires an alpha channel. If none is available, an all opaque alpha channel is implicitedly created. Specify the count and the image to duplicate by its index in the sequence. Encipher pixels for later deciphering by -decipher. Specify endianness MSB or LSB of the image. To perform histogram equalization on all channels in concert, transform the image into some other color space, such as HSL, OHTA, YIQ or YUV, then equalize the appropriate intensity-like channel, then convert back to RGB.
For example using HSL, we have For YIQ, YUV and OHTA use the red channel. For example, OHTA is a principal components transformation that puts most of the information in the first channel. Here we have Alter channel pixels by evaluating an arithmetic, relational, or logical expression. See the -function operator for some multi-parameter functions. See the -fx operator if more elaborate calculations are needed.
The behaviors of each operator are summarized in the following list. For brevity, the numerical value of a "pixel" referred to below is the value of the corresponding channel of that pixel, while a "normalized pixel" is that number divided by the maximum installation-dependent value QuantumRange.
If normalized pixels are used, they are restored, following the other calculations, to the full range by multiplying by QuantumRange. The specified functions are applied only to each previously set -channel in the image. If necessary, the results of the calculations are truncated clipped to fit in the interval [0, QuantumRange ]. To print a complete list of -evaluate operators, use -list evaluate. AddModulus has been added as of ImageMagick 6. It is therefore equivalent to Add unless the resulting pixel value is outside the interval [0, QuantumRange ].
Exp or Exponential has been added as of ImageMagick 6. The value used with Exp should be negative so as to produce a decaying exponential function. Non-negative values will always produce results larger unity and thus outside the interval [0, QuantumRange ].
The formula is expressed below. If the input image is squared, for example, using -function polynomial "2 0 0" , then a decaying Gaussian function will be the result. Log has been added as of ImageMagick 6. This a scaled log function. The value used with Log provides a scaling factor that adjusts the curvature in the graph of the log function.
The formula applied to a normalized value u is below. Pow has been added as of ImageMagick 6. Note that Pow is related to the -gamma operator. For example, -gamma 2 is equivalent to -evaluate pow 0. The value used with -gamma is simply the reciprocal of the value used with Pow.
Cosine and Sine was added as of IM v6. The synonyms Cos and Sin may also be used. The value scaling of the period of the function its frequency , and thus determines the number of 'waves' that will be generated over the input color range. For example, if the value is 1, the effective period is simply the QuantumRange ; but if the value is 2, then the effective period is the half the QuantumRange.
See also the -function operator, which is a multi-value version of evaluate. Alter channel pixels by evaluating an arithmetic, relational, or logical expression over a sequence of images. Ensure all the images in the sequence are in the same colorspace, otherwise you may get unexpected results, e.
add -colorspace sRGB to your command-line. To print a complete list of -evaluate-sequence operators, use -list evaluate. No further options are processed after this option. Useful in a script to force the magick command to exit without actually closing the pipeline that it is processing options from. You can also use the option as a final option on the magick command line instead of an implicit output image, to completely prevent any image write.
Note, even the NULL: coder requires at least one image, for it to 'not write'! This option does not require any images at all. If the image is enlarged, unfilled areas are set to the background color. To position the image, use offsets in the geometry specification or precede with a -gravity setting. To specify how to compose the image with the background, use -compose.
The following command reduces or expands a JPEG image to fit on an x display. If the aspect ratio of the input image isn't exactly , then the image is centered on an x black canvas:. The command can also be used with a ratio. If the image is not already at that ratio, it will be cropped to fit it. The -gravity setting has the expected effects. The following command crops a JPEG image so that it has a ratio:.
This option is most useful for extracting a subregion of a very large raw image. Note that these two commands are equivalent:. This setting suggests a font family that ImageMagick should try to use for rendering text.
If the family can be found it is used; if not, a default font e. Note, the family can be a CSS-style font list. For other settings that affect fonts, see the options -font , -pointsize , -stretch , -style , and -weight.
Display co-occurrence matrix texture measure features for each channel in the image in each of four directions horizontal, vertical, left and right diagonals for the specified distance.
This option is new as of ImageMagick 6. It transforms an image from the normal spatial domain to the frequency domain. In the frequency domain, an image is represented as a superposition of complex sinusoidal waves of varying amplitudes. The image x and y coordinates are the possible frequencies along the x and y directions, respectively, and the pixel intensity values are complex numbers that correspond to the sinusoidal wave amplitudes.
See for example, Fourier Transform , Discrete Fourier Transform and Fast Fourier Transform. A single image name is provided as output for this option. However, the output result will have two components. It is either a two-frame image or two separate images, depending upon whether the image format specified supports multi-frame images. The reason that we get a dual output result is because the frequency domain represents an image using complex numbers, which cannot be visualized directly.
Therefore, the complex values are automagically separated into a two-component image representation. The first component is the magnitude of the complex number and the second is the phase of the complex number. See for example, Complex Numbers. The magnitude and phase component images must be specified using image formats that do not limit the color or compress the image.
Thus, MIFF, TIF, PFM, EXR and PNG are the recommended image formats to use. All of these formats, except PNG support multi-frame images. So for example,. The input image can be any size, but if not square and even-dimensioned, it is padded automagically to the larger of the width or height of the input image and to an even number of pixels.
The resulting output magnitude and phase images is square at this size. The kind of padding relies on the -virtual-pixel setting. Both output components will have dynamic ranges that fit within [0, QuantumRange ], so that HDRI need not be enabled. The first few releases had non-HDRI scaled but HDRI not scaled. The magnitude image is not scaled and thus generally will contain very small values.
As such, the image normally will appear totally black. In order to view any detail, the magnitude image typically is enhanced with a log function into what is usually called the spectrum. A log function is used to enhance the darker values more in comparison to the lighter values.
This can be done, for example, as follows:. where either -contrast-stretch 0 or -auto-level is used to scale the image to full dynamic range, first. The argument to the -evaluate log typically is specified between and 10,, depending upon the amount of detail that one wants to bring out in the spectrum. Larger values produce more visible detail. Too much detail, however, may hide the important features.
The FFTW delegate library is required to use -fft. However, as the real and imaginary components can contain negative values, this requires that IM be configured with HDRI enabled. In this case, you must use either MIFF, TIF, PFM or MPC formats for the real and imaginary component results, since they are formats that preserve both negative and fractional values without clipping them or truncating the fractional part.
For more about HDRI go the ImageMagick Usage pages, Fred's Fourier Processing With ImageMagick page or this Wikipedia entry. By default the FFT is normalized and the IFT is not. This option accepts a color name, a hex color, or a numerical RGB, RGBA, HSL, HSLA, CMYK, or CMYKA specification. See Color Names for a description of how to properly specify the color argument. Enclose the color specification in quotation marks to prevent the " " or the parentheses from being interpreted by your shell.
Use this type of filter when resizing or distorting an image. Use this option to affect the resizing operation of an image during operations such as -resize and -distort. For example you can use a simple resize filter such as:. The Bessel and Sinc filter is also provided as well as a faster SincFast equivalent form.
However these filters are generally useless on their own as they are infinite filters that are being clipped to the filters support size. Their direct use is not recommended except via expert settings see below. Instead these special filter functions are typically windowed by a windowing function that the -filter setting defines.
That is using these functions will define a 'Windowed' filter, appropriate to the operator involved. Windowed filters include:. Also one special self-windowing filter is also provided Lagrange , which will automagically re-adjust its function depending on the current 'support' or 'lobes' expert settings see below.
If you do not select a filter with this option, the filter defaults to Mitchell for a colormapped image, an image with a matte channel, or if the image is enlarged. Otherwise the filter default to Lanczos. You can modify how the filter behaves as it scales your image through the use of these expert settings see also -define and -set To extract the data for a raw windowing function, combine it with a ' Box ' filter.
For example the ' Welch parabolic windowing function. Note that the use of expert options is provided for image processing experts who have studied and understand how resize filters work.
Without this knowledge, and an understanding of the definition of the actual filters involved, using expert settings are more likely to be detrimental to your image resizing. This is a simple alias for the -layers method "flatten". Flood fill starts from the given 'seed point' which is not gravity affected. Any color that matches within -fuzz color distance of the given color argument, connected to that 'seed point' will be replaced with the current -fill color.
Note that if the pixel at the 'seed point' does not itself match the given color according to -fuzz , then no action will be taken. This operator works more like the -opaque option, than a more general flood fill that reads the matching color directly at the 'seed point'. For this form of flood fill, look at -draw and its 'color floodfill' drawing method. Set the font to use when annotating images with text, or creating labels.
To print a complete list of fonts, use the -list font option for versions prior to 6. In addition to the fonts specified by the above pre-defined list, you can also specify a font from a specific source. For example Arial. ttf is a TrueType font file, ps:helvetica is PostScript font, and x:fixed is X11 font. For other settings that affect fonts, see the options -family , -stretch , -style , and -weight.
To specify an explicit font filename or collection, specify the font path preceded with a , e. You can specify the font face index for font collections, e. When used with the mogrify utility, this option converts any image to the image format you specify. For a list of image format types supported by ImageMagick, use -list format. By default the file is written to its original name. However, if the filename extension matches a supported format, the extension is replaced with the image format type specified with -format.
For example, if you specify tiff as the format type and the input image filename is image. gif , the output image filename becomes image. See Format and Print Image Properties for an explanation on how to specify the argument to this option. The color of the border is specified with the -mattecolor command line option. The size portion of the geometry argument indicates the amount of extra width and height that is added to the dimensions of the image.
If no offsets are given in the geometry argument, then the border added is a solid color. Offsets x and y , if present, specify that the width and height of the border is partitioned to form an outer bevel of thickness x pixels and an inner bevel of thickness y pixels.
Negative offsets make no sense as frame arguments. The -frame option is affected by the current -compose setting and assumes that this is using the default ' Over ' composition method. It generates an image of the appropriate size with the current -bordercolor setting, and then draws the frame of four distinct colors close to the current -mattecolor.
The original image is then overlaid onto center of this image. This operator performs calculations based on the given arguments to modify each of the color values for each previously set -channel in the image. See -evaluate for details concerning how the results of the calculations are handled. This is can be considered a multi-argument version of the -evaluate operator. Added in ImageMagick 6. Here, parameters is a comma-separated list of numerical values.
The number of values varies depending on which function is selected. Choose the function from:. To print a complete list of -function operators, use -list function. Descriptions follow. The Polynomial function takes an arbitrary number of parameters, these being the coefficients of a polynomial, in decreasing order of degree.
That is, entering. The Polynomial function can be used in place of Set the constant polynomial and Add , Divide , Multiply , and Subtract some linear polynomials of the -evaluate operator.
The -level operator also affects channels linearly. Some correspondences follow. The Polynomial function gives great versatility, since polynomials can be used to fit any continuous curve to any degree of accuracy desired.
The Sinusoid function can be used to vary the channel values sinusoidally by setting frequency, phase shift, amplitude, and a bias. These values are given as one to four parameters, as follows,. where phase is in degrees. The domain [0,1] of the function corresponds to 0 through freq × degrees. The result is that if a pixel's normalized channel value is originally u , its resulting normalized value is given by.
For example, the following generates a curve that starts and ends at 0. The default values of amp and bias are both. The default for phase is 0. The Sinusoid function generalizes Sin and Cos of the -evaluate operator by allowing varying amplitude, phase and bias.
The correspondence is as follows. The ArcSin function generates the inverse curve of a Sinusoid, and can be used to generate cylindrical distortion and displacement maps.
The curve can be adjusted relative to both the input values and output range of values. with all values given in terms of normalized color values 0. Defaulting to values covering the full range from 0. The ArcTan function generates a curve that smooth crosses from limit values at infinities, though a center using the given slope value. All these values can be adjusted via the arguments. A number of algorithms search for a target color. By default the color must be exact.
Use this option to match colors that are close to the target color in RGB space. For example, if you want to automagically trim the edges of an image with -trim but the image was scanned and the target background color may differ by a small amount.
This option can account for these differences. If the first character of expression is , the expression is read from a file titled by the remaining characters in the string. See FX, The Special Effects Image Operator for a detailed discussion of this option.
The same color image displayed on two different workstations may look different due to differences in the display monitor. Use gamma correction to adjust for this color difference. Reasonable values extend from 0. Gamma less than 1. Large adjustments to image gamma may result in the loss of some image information if the pixel quantum size is only eight bits quantum range 0 to This option is useful if the image is of a known gamma but not set as an image attribute e.
PNG images. Write the "file gamma" which is the reciprocal of the display gamma; e. The radius is only used to determine the size of the array which will hold the calculated Gaussian distribution. The larger the Radius the radius the slower the operation is. This differs from the faster -blur operator in that a full 2-dimensional convolution is used to generate the weighted average of the neighboring pixels. Sets the current gravity suggestion for various other settings and options.
Choices include: NorthWest , North , NorthEast , West , Center , East , SouthWest , South , SouthEast. Use -list gravity to get a complete list of -gravity settings available in your ImageMagick installation. The direction you choose specifies where to position text or subimages. For example, a gravity of Center forces the text to be centered within the image.
By default, the image gravity is undefined. See -draw for more details about graphic primitives. Only the text primitive of -draw is affected by the -gravity option. The -gravity option is also used in concert with the -geometry setting and other settings or options that take geometry as an argument, such as the -crop option.
If a -gravity setting occurs before another option or setting having a geometry argument that specifies an offset, the offset is usually applied to the point within the image suggested by the -gravity argument. Thus, in the following command, for example, suppose the file image. png has dimensions x The argument to -gravity is Center , which suggests the midpoint of the image, at the point , In addition, the -gravity affects the region itself, which is centered at the pixel coordinate 60, When used as an option to composite , -gravity gives the direction that the image gravitates within the composite.
When used as an option to montage , -gravity gives the direction that an image gravitates within a tile. The default gravity is Center for this purpose. This will use one of the -intensity methods to convert the given image into a grayscale image. Note that a 'colorspace' intensity method will produce the same result regardless of the current colorpsace of the image.
But a 'mathematical' intensity method depends on the current colorspace the image is currently using. While this operation uses an -intensity method, it does not use or set the -intensity setting, so will not affect other operations that may use that setting. A Hald color lookup table is a 3-dimensional color cube mapped to 2 dimensions. Create it with the HALD: prefix e. You can apply any color transformation to the Hald image and then use this option to apply the transform to the image.
This option provides a convenient method for you to use Gimp or Photoshop to make color corrections to the Hald CLUT image and subsequently apply them to multiple images using an ImageMagick script. Note that the representation is only of the normal RGB color space and that the whole color value triplet is used for the interpolated lookup of the represented Hald color cube image.
See also -clut which provides color value replacement of the individual color channels, usually involving a simpler grayscale image. g: grayscale to color replacement, or modification by a histogram mapping. Use the Hough line detector with any binary edge extracted image to locate and draw any straight lines that it finds. The process accumulates counts for every white pixel in the binary edge image for every possible orientation for angles from 0 to in 1 deg increments and distance from the center of the image to the corners in 1 px increments.
It stores the counts in an accumulator matrix of angle vs distance. Next it searches the accumulator for peaks in counts and converts the locations of the peaks to slope and intercept in the normal x,y input image space.
The lines are drawn from the given endpoints. The counts are a measure of the length of the lines. The WxH arguments specify the filter size for locating the peaks in the Hough accumulator. The threshold excludes lines whose counts are less than the threshold value.
Use -background to specify the color of the background onto which the lines will be drawn. The default is black. Use -fill to specify the color of the lines. Use -stroke and -strokewidth to specify the thickness of the lines. The default is black and no strokewidth.
A text file listing the endpoints and counts may be created by using the suffix,. mvg, for the output image. Offsets, if present in the geometry specification, are handled in the same manner as the -geometry option, using X11 style to handle negative offsets. This information is printed: image scene number; image name; image size; the image class DirectClass or PseudoClass ; the total number of unique colors; and the number of seconds to read and transform the image.
Refer to MIFF for a description of the image class. If -colors is also specified, the total unique colors in the image and color reduction error values are printed. Refer to color reduction algorithm for a description of these values. If -verbose precedes this option, copious amounts of image properties are displayed including image statistics, profiles, image histogram, and others.
It transforms a pair of magnitude and phase images from the frequency domain to a single image in the normal or spatial domain. For example, depending upon the image format used to store the result of the -fft , one would use either. The FFTW delegate library is required to use -ift.
By default the IFT is not normalized and the FFT is. reference illuminant. This option takes last image in the current image sequence and inserts it at the given index.
If a negative index is used, the insert position is calculated before the last image is removed from the sequence. As such -insert -1 will result in no change to the image sequence. In other words, insert the last image, at the end of the current image sequence. Consequently this has no effect on the image sequence order.
ImageMagick provides a number of methods used in situations where an operator needs to determine a single grayscale value for some purpose, from an image with red, green, and blue pixel components. Typically the RecLuma formula is used, which is the same formula used when converting images to -colorspace gray. The following formulas are currently provided, and will first convert the pixel values to linear-RGB or non-linear sRGB colorspace before being applied to calculate the final greyscale value.
Note that the above R,G,B values is the image's linear-RGB values, while R',G',B' are sRGB non-linear values. These intensity methods are mathematical in nature and will use the current value in the images respective R,G,B channel regardless of what that is, or what colorspace the image is currently using. These methods are often used for other purposes, such as generating a grayscale difference image between two color images using -compose ' Difference ' composition.
For example The 'MS' Mean Squared setting is good for minimizing color error comparisions. The method 'RMS' Root Mean Squared for example is appropriate for calculating color vector distance, from a color difference image. This is equivalent to the color only component of the -fuzz factor color compare setting. See also -grayscale which applies one of the above grayscaling formula directly to an image without setting the -intensity setting. The -colorspace gray image conversion also uses the current intensity setting, but will always convert the image to the appropriate sRGB or linear-RGB colorspace before appling the above function.
To print a complete list of possible pixel intensity setting methods, use -list intensity. Use this option to affect the color management operation of an image see -profile. Choose from these intents: Absolute, Perceptual, Relative, Saturation. The default intent is Perceptual for the sRGB colorspace and undefined for the RGB and gray colorspaces. This option is used to specify the type of interlacing scheme for raw image formats such as RGB or YUV.
Partition is like plane except the different planes are saved to individual files e. R, image. G, and image. Use Line or Plane to create an interlaced PNG or GIF or progressive JPEG image. Set the pixel color interpolation method to use when looking up a color based on a floating point or real value.
When looking up the color of a pixel using a non-integer floating point value, you typically fall in between the pixel colors defined by the source image. This setting determines how the color is determined from the colors of the pixels surrounding that point. That is how to determine the color of a point that falls between two, or even four different colored pixels. This most important for distortion operators such as -distort , -implode , -transform and -fx.
See also -virtual-pixel , for control of the lookup for positions outside the boundaries of the image. Resize with interpolation. See the -interpolate setting. Kmeans iterative color reduction e. Colors is the desired number of colors. Initial colors are found using color quantization. Processing finishes, if either iterations or tolerance are reached. A color list overrides the color quantization. A non-empty list of colors overrides the number of colors.
Any unassigned initial colors are assigned random colors from the image. The radius is more important than the sigma. The sigma provides a bit of additional smoothing control. Use this option to assign a specific label to the image, as it is read in or created. You can use the -set operation to re-assign a the labels of images already read in. Image formats such as TIFF, PNG, MIFF, supports saving the label information with the image. When saving an image to a PostScript file, any label assigned to an image is used as a header string to print above the postscript image.
You can include the image filename, type, width, height, or other image attribute by embedding special format character. See Format and Print Image Properties for details of the percent escape codes.
assigns an image label of MIFF:bird. miff x to the " bird. miff " image and whose width is and height is , as it is read in. You can remove all labels from an image by assigning the empty string. A label is not drawn on the image, but is embedded in the image datastream via Label tag or similar mechanism. If you want the label to be visible on the image itself, use the -draw option, or during the final processing in the creation of an image montage.
If the first character of string is , the image label is read from a file titled by the remaining characters in the string. Labels in a file are literal, no embedded formatting characters are recognized.
Adaptively threshold each pixel based on the value of pixels in a surrounding window. If the current pixel is lighter than this average plus the optional offset , then it is made white, otherwise it is made black. Small variations in pixel values such as found in scanned documents can be ignored if offset is positive. A locally elected Democratic official says the proposed revisions to Washington, D. Fox News medical contributor Dr. Marc Siegel joins 'Fox News Live' to discuss the history surge in respiratory illnesses in the United States.
Defense attorney and formal prosecutor Robert Schalk joins 'Fox News Live' to discuss an FTX lawsuit against big-name celebrities. But most Americans aren't buying it. Even some progressives want an alternative. The week's best and worst from Kim Strassel, Collin Levy, Allysia Finley and Dan Henninger. The Biden administration is engaged in a multitude of legal battles over U. immigration and border security policies, including the Title 42 public health order.
It can be run on one or more directories, or compressed package tar archives with extension. tgz ,. It is strongly recommended that the final checks are run on a tar archive prepared by R CMD build. A warning is given for directory names that look like R package check directories — many packages have been submitted to CRAN containing these.
Note that the latter might give false positives in that the symbols might be pulled in with external libraries and could never be called. Of course, released packages should be able to run at least their own examples. If there is an error 51 in executing the R code in vignette foo. ext , a log file foo. log is created in the check directory.
Use R CMD check --help to obtain more information about the usage of the R package checker. A subset of the checking steps can be selected by adding command-line options. Rprofile , by e. which reports unused local assignments. Not only does this point out computations which are unnecessary because their results are unused, it also can uncover errors.
This can give false positives, most commonly because of non-standard evaluation for formulae and because the intention is to return objects in the environment of a function for later use.
Complete checking of a package which contains a file README. You do need to ensure that the package is checked in a suitable locale if it contains non- ASCII characters. Such packages are likely to fail some of the checks in a C locale, and R CMD check will warn if it spots the problem. You should be able to check any package in a UTF-8 locale if one is available. Beware that although a C locale is rarely used at a console, it may be the default if logging in remotely or for batch jobs.
Often R CMD check will need to consult a CRAN repository to check details of uninstalled packages. Next: Building binary packages , Previous: Checking packages , Up: Checking and building packages [ Contents ][ Index ].
gz files or in binary form. The source form can be installed on all platforms with suitable tools and is the usual form for Unix-like systems; the binary form is platform-specific, and is the more common distribution form for the Windows and macOS platforms. Using R CMD build , the R package builder, one can build R package tarballs from their sources for example, for subsequent release. Prior to actually building the package in the standard gzipped tar file format, a few diagnostic checks and cleanups are performed.
Run-time checks whether the package works correctly should be performed using R CMD check prior to invoking the final build procedure. To exclude files from being put into the package, one can specify a list of exclude patterns in file. Rbuildignore in the top-level source directory. These patterns should be Perl-like regular expressions see the help for regexp in R for the precise details , one per line, to be matched case-insensitively against the file and directory names relative to the top-level package source directory.
In addition, directories from source control systems 54 or from eclipse 55 , directories with names check , chm , or ending. In addition, same-package tarballs from previous builds and their binary forms will be excluded from the top-level directory, as well as those files in the R , demo and man directories which are flagged by R CMD check as having invalid names.
Use R CMD build --help to obtain more information about the usage of the R package builder. To do so it installs the current package into a temporary library tree, but any dependent packages need to be installed in an available library tree see the Note: at the top of this section.
Similarly, if the. If there are any install-time or render-time macros, a. pdf version of the package manual will be built and installed in the build subdirectory. This allows CRAN or other repositories to display the manual even if they are unable to install the package. One of the checks that R CMD build runs is for empty source directories. The --resave-data option allows saved images. rda and. RData files in the data directory to be optimized for size.
It will also compress tabular files and convert. R files to saved images. Where a non-POSIX file system is in use which does not utilize execute permissions, some care is needed with permissions. This applies on Windows and to e. FAT-formatted drives and SMB-mounted file systems on other OSes. info returns. A particular issue is packages being built on Windows which are intended to contain executable scripts such as configure and cleanup : R CMD build ensures those two are recorded with execute permission.
Directory build of the package sources is reserved for use by R CMD build : it contains information which may not easily be created when the package is installed, including index information on the vignettes and, rarely, information on the help pages and perhaps a copy of the PDF reference manual see above.
Previous: Building package tarballs , Up: Checking and building packages [ Contents ][ Index ]. Binary packages are compressed copies of installed versions of packages.
The format and filename are platform-specific; for example, a binary package for Windows is usually supplied as a. zip file, and for the macOS platform the default binary package file extension is. R CMD INSTALL --build pkg where pkg is either the name of a source tarball in the usual. gz format or the location of the directory of the package source to be built. This operates by first installing the package and then packing the installed binaries into the appropriate binary package file for the particular platform.
By default, R CMD INSTALL --build will attempt to install the package into the default library tree for the local installation of R. This has two implications:. To prevent changes to the present working installation or to provide an install location with write access, create a suitably located directory with write access and use the -l option to build the package in the chosen location.
The usage is then. where location is the chosen directory with write access. The package will be installed as a subdirectory of location , and the package binary will be created in the current directory.
Other options for R CMD INSTALL can be found using R CMD INSTALL --help , and platform-specific details for special cases are discussed in the platform-specific FAQs. Note that this is intended for developers on other platforms who do not have access to Windows but wish to provide binaries for the Windows platform.
Next: Package namespaces , Previous: Checking and building packages , Up: Creating R packages [ Contents ][ Index ]. In addition to the help files in Rd format, R packages allow the inclusion of documents in arbitrary other formats. Pointers from package help indices to the installed documents are automatically created. To ensure that they can be accessed from a browser as an HTML index is provided , the file names should start with an ASCII letter and be comprised entirely of ASCII letters or digits or hyphen or underscore.
A special case is package vignettes. Sweave, provided by the R distribution, is the default engine. Other vignette engines besides Sweave are supported; see Non-Sweave vignettes. Package vignettes have their sources in subdirectory vignettes of the package sources. Sweave vignette sources are normally given the file extension. Rnw or. Rtex , but for historical reasons extensions Snw and.
Stex are also recognized. Sweave allows the integration of LaTeX documents: see the Sweave help page in R and the Sweave vignette in package utils for details on the source document format. Package vignettes are tested by R CMD check by executing all R code chunks they contain except those marked for non-evaluation, e. The R working directory for all vignette tests in R CMD check is a copy of the vignette source directory. All other files needed to re-make the vignettes such as LaTeX style files, BibTeX input files and files for any figures not created by running the code in the vignette must be in the vignette source directory.
By including the vignette outputs in the package sources it is not necessary that these can be re-built at install time, i. By default R CMD build will run Sweave on all Sweave vignette source files in vignettes.
If Makefile is found in the vignette source directory, then R CMD build will try to run make after the Sweave runs, otherwise texi2pdf is run on each.
tex file produced. All the usual caveats about including a Makefile apply. It must be portable no GNU extensions , use LF line endings and must work correctly with a parallel make : too many authors have written things like.
Metadata lines can be placed in the source file, preferably in LaTeX comments in the preamble. This index is linked from the HTML help index for the package. Do watch that PDFs are not too large — one in a CRAN package was 72MB! This is usually caused by the inclusion of overly detailed figures, which will not render well in PDF viewers.
Sometimes it is much better to generate fairly high resolution bitmap PNG, JPEG figures and include those in the PDF document. See the description of the. Rinstignore file for full details. Next: Non-Sweave vignettes , Previous: Writing package vignettes , Up: Writing package vignettes [ Contents ][ Index ].
Vignettes will in general include descriptive text, R input, R output and figures, LaTeX include files and bibliographic references. As any of these may contain non- ASCII characters, the handling of encodings can become very complicated.
The vignette source file should be written in ASCII or contain a declaration of the encoding see below. This applies even to comments within the source file, since vignette engines process comments to look for options and metadata lines. Sweave will produce a. tex file in the current encoding, or in UTF-8 if that is declared. Non- ASCII encodings need to be declared to LaTeX via a line like.
For files where this line is not needed e. chapters included within the body of a larger document, or non-Sweave vignettes , the encoding may be declared using a comment like. If no declaration is given in the vignette, it will be assumed to be in the encoding declared for the package.
If there is no encoding declared in either place, then it is an error to use non- ASCII characters in the vignette. Sweave will also parse and evaluate the R code in each chunk. One thing people often forget is that the R output may not be ASCII even for ASCII R sources, for many possible reasons.
The final issue is the encoding of figures — this applies only to PDF figures and not PNG etc. The PDF figures will contain declarations for their encoding, but the Sweave option pdf.
encoding may need to be set appropriately: see the help for the pdf graphics device. That package did not have a declared encoding, and its vignette was in ASCII. However, the data it displays are read from a UTF-8 CSV file and will be assumed to be in the current encoding, so fortunes. tex will be in UTF-8 in any locale. Had read. table been told the data were UTF-8, fortunes. Previous: Encodings and vignettes , Up: Writing package vignettes [ Contents ][ Index ].
For example knitr version 1. tex files from a variation on Sweave format, and. These engines replace the Sweave function with other functions to convert vignette source files into LaTeX files for processing into. pdf , or directly into. pdf or. html files.
The Stangle function is replaced with a function that extracts the R source from a vignette. R recognizes non-Sweave vignettes using filename extensions specified by the engine. For example, the knitr package supports the extension. This specifies the name of a package and an engine to use in place of Sweave in processing the vignette. If more than one package is specified as a builder, they will be searched in the order given there. The utils package is always implicitly appended to the list of builder packages, but may be included earlier to change the search order.
The vignette engine can produce. tex ,. pdf , or. html files as output. If it produces. tex files, R will call texi2pdf to convert them to. pdf for display to the user unless there is a Makefile in the vignettes directory. Package writers who would like to supply vignette engines need to register those engines in the package. onLoad function. For example, that function could make the call.
The actual registration in knitr is more complicated, because it supports other input formats. See the? tools::vignetteEngine help topic for details on engine registration. Next: Writing portable packages , Previous: Writing package vignettes , Up: Creating R packages [ Contents ][ Index ]. R has a namespace management system for code in packages. This system allows the package writer to specify which variables in the package should be exported to make them available to package users, and which variables should be imported from other packages.
The namespace for a package is specified by the NAMESPACE file in the top level package directory. This file contains namespace directives describing the imports and exports of the namespace. Additional directives register any shared objects to be loaded and any S3-style methods that are provided. Note that although the file looks like R code and often has R-style comments it is not processed as R code.
Only very simple conditional processing of if statements is implemented. Packages are loaded and attached to the search path by calling library or require. Only the exported variables are placed in the attached frame. Loading a package that imports variables from other packages will cause these other packages to be loaded as well unless they have already been loaded , but they will not be placed on the search path by these implicit loads.
Thus code in the package can only depend on objects in its own namespace and its imports including the base namespace being visible Namespaces are sealed once they are loaded. Sealing means that imports and exports cannot be changed and that internal variable bindings cannot be changed. Sealing allows a simpler implementation strategy for the namespace mechanism and allows code analysis and compilation tools to accurately identify the definition corresponding to a global variable reference in a function body.
The namespace controls the search strategy for variables used by functions in the package. If not found locally, R searches the package namespace first, then the imports, then the base namespace and then the normal search path so the base namespace precedes the normal search rather than being at the end of it.
Next: Registering S3 methods , Previous: Package namespaces , Up: Package namespaces [ Contents ][ Index ]. Exports are specified using the export directive in the NAMESPACE file. A directive of the form.
specifies that the variables f and g are to be exported. fractions must be. For packages with many variables to export it may be more convenient to specify the names to export with a regular expression using exportPattern. The directive. exports all variables that do not start with a period. However, such broad patterns are not recommended for production code: it is better to list all exports or use narrowly-defined groups.
This pattern applies to S4 classes. Beware of patterns which include names starting with a period: some of these are internal-only variables and should never be exported, e. Packages implicitly import the base namespace. Variables exported from other packages with namespaces need to be imported explicitly using the directives import and importFrom. The import directive imports all exported variables from the specified package s.
Thus the directives. specifies that all exported variables in the packages foo and bar are to be imported. If only some of the exported variables from a package are needed, then they can be imported using importFrom. specifies that the exported variables f and g of the package foo are to be imported. Using importFrom selectively rather than import is good practice and recommended notably when importing from packages with more than a dozen exports and especially from those written by others so what they export can change in future.
To import every symbol from a package but for a few exceptions, pass the except argument to import. imports every symbol from foo except bar and baz. The value of except should evaluate to something coercible to a character vector, after substituting each symbol for its corresponding string.
It is possible to export variables from a namespace which it has imported from other namespaces: this has to be done explicitly and not via exportPattern. If a package only needs a few objects from another package it can use a fully qualified variable reference in the code instead of a formal import.
A fully-qualified reference to the function f in package foo is of the form foo::f. Evaluating foo::f will cause package foo to be loaded, but not attached, if it was not loaded already—this can be an advantage in delaying the loading of a rarely used package.
Using the foo::f form will be necessary when a package needs to use a function of the same name from more than one namespace. Using foof instead of foo::f allows access to unexported objects. This is generally not recommended, as the existence or semantics of unexported objects may be changed by the package author in routine maintenance. Next: Load hooks , Previous: Specifying imports and exports , Up: Package namespaces [ Contents ][ Index ].
The standard method for S3-style UseMethod dispatching might fail to locate methods defined in a package that is imported but not attached to the search path. To ensure that these methods are available the packages defining the methods should ensure that the generics are imported and register the methods using S3method directives. If a package defines a function print. foo intended to be used as a print method for class foo , then the directive.
ensures that the method is registered and available for UseMethod dispatch, and the function print. foo does not need to be exported. Since the generic print is defined in base it does not need to be imported explicitly. It is possible to specify a third argument to S3method, the function to be used as the method, for example.
As from R 3. function gen. cls will get registered as an S3 method for class cls and generic gen from package pkg only when the namespace of pkg is loaded.
Next: useDynLib , Previous: Registering S3 methods , Up: Package namespaces [ Contents ][ Index ]. There are a number of hooks called as packages are loaded, attached, detached, and unloaded. See help ". onLoad" for more details. Since loading and attaching are distinct operations, separate hooks are provided for each.
These hook functions are called. onLoad and. They both take arguments 63 libname and pkgname ; they should be defined in the namespace but not exported. Packages can use a. onDetach or. lib function provided the latter is exported from the namespace when detach is called on the package.
It is called with a single argument, the full path to the installed package. There is also a hook. onUnload and. onDetach should be defined in the namespace and not exported, but. lib does need to be exported. Packages are not likely to need.
onAttach except perhaps for a start-up banner ; code to set options and load shared objects should be placed in a.
onLoad function, or use made of the useDynLib directive described next. These hooks are often used incorrectly. People forget to export. Compiled code should be loaded in. onLoad or via a useDynLb directive: see below and unloaded in. by pkgname::fun and that a package can be detached and re-attached whilst its namespace remains loaded.
It is good practice for these functions to be quiet. Any messages should use packageStartupMessage so users include check scripts can suppress them if desired. Next: An example , Previous: Load hooks , Up: Package namespaces [ Contents ][ Index ]. A NAMESPACE file can contain one or more useDynLib directives which allows shared objects that need to be loaded.
registers the shared object foo 65 for loading with library. Loading of registered object s occurs after the package code has been loaded and before running the load hook function. Packages that would only need a load hook function to load a shared object can use the useDynLib directive instead.
The useDynLib directive also accepts the names of the native routines that are to be used in R via the. Call ,. Fortran and. External interface functions. These are given as additional arguments to the directive, for example,. These can be used in the. External calls in place of the name of the routine and the PACKAGE argument.
For instance, we can call the routine myRoutine from R with the code. There are at least two benefits to this approach. Firstly, the symbol lookup is done just once for each symbol rather than each time the routine is invoked. Secondly, this removes any ambiguity in resolving symbols that might be present in more than one DLL. However, this approach is nowadays deprecated in favour of supplying registration information see below.
In some circumstances, there will already be an R variable in the package with the same name as a native symbol. For example, we may have an R function in the package named myRoutine.
In this case, it is necessary to map the native symbol to a different R variable name. This can be done in the useDynLib directive by using named arguments. It may be too costly to compute these for many routines when the package is loaded if many of these routines are not likely to be used.
In this case, one can still perform the symbol resolution correctly using the DLL, but do this each time the routine is called. Given a reference to the DLL as an R variable, say dll , we can call the routine myRoutine using the expression. This is the same computation as above where we resolve the symbol when the package is loaded.
In order to use this dynamic approach e. For example, if we wanted to assign the DLL reference for the DLL foo in the example above to the variable myDLL , we would use the following directive in the NAMESPACE file:. If the package has registration information see Registering native routines , then we can use that directly rather than specifying the list of symbols again in the useDynLib directive in the NAMESPACE file.
Each routine in the registration information is specified by giving a name by which the routine is to be specified along with the address of the routine and any information about the number and type of the parameters.
Using the. registration argument of useDynLib , we can instruct the namespace mechanism to create R variables for these symbols. For example, suppose we have the following registration information for a DLL named myDLL :.
Note that the names for the R variables are taken from the entry in the registration information and do not need to be the same as the name of the native routine. This allows the creator of the registration information to map the native symbols to non-conflicting variable names in R, e.
Using argument. fixes allows an automatic prefix to be added to the registered symbols, which can be useful when working with an existing package.
For example, package KernSmooth has. NB : Using these arguments for a package which does not register native symbols merely slows down the package loading although many CRAN packages have done so. Once symbols are registered, check that the corresponding R variables are not accidentally exported by a pattern in the NAMESPACE file.
Next: Namespaces with S4 classes and methods , Previous: useDynLib , Up: Package namespaces [ Contents ][ Index ]. As an example consider two packages named foo and bar. The R code for package foo in file foo. Some C code defines a C function compiled into DLL foo with an appropriate extension.
The NAMESPACE file for this package is. Calling library bar loads bar and attaches its exports to the search path. Package foo is also loaded but not attached to the search path. A call to g produces. This is consistent with the definitions of c in the two settings: in bar the function c is defined to be equivalent to sum , but in foo the variable c refers to the standard function c in base.
Previous: An example , Up: Package namespaces [ Contents ][ Index ]. Some additional steps are needed for packages which make use of formal S4-style classes and methods unless these are purely used internally. plus any classes and methods which are to be exported need to be declared in the NAMESPACE file. For example, the stats4 package has. All S4 classes to be used outside the package need to be listed in an exportClasses directive.
Alternatively, they can be specified using exportClassPattern 66 in the same style as for exportPattern. To export methods for generics from other packages an exportMethods directive can be used. Note that exporting methods on a generic in the namespace will also export the generic, and exporting a generic in the namespace will also export its methods.
If the generic function is not local to this package, either because it was imported as a generic function or because the non-generic version has been made generic solely to add S4 methods to it as for functions such as coef in the example above , it can be declared via either or both of export or exportMethods , but the latter is clearer and is used in the stats4 example above.
In particular, for primitive functions there is no generic function, so export would export the primitive, which makes no sense. On the other hand, if the generic is local to this package, it is more natural to export the function itself using export , and this must be done if an implicit generic is created without setting any methods for it as is the case for AIC in stats4.
A non-local generic function is only exported to ensure that calls to the function will dispatch the methods from this package and that is not done or required when the methods are for primitive functions.
For this reason, you do not need to document such implicitly created generic functions, and undoc in package tools will not report them. If a package uses S4 classes and methods exported from another package, but does not import the entire namespace of the other package 67 , it needs to import the classes and methods explicitly, with directives.
listing the classes and functions with methods respectively. Suppose we had two small packages A and B with B using A. Then they could have NAMESPACE files. Note that importMethodsFrom will also import any generics defined in the namespace on those methods.
It is important if you export S4 methods that the corresponding generics are available. You may for example need to import coef from stats to make visible a function to be converted into its implicit generic.
But it is better practice to make use of the generics exported by stats4 as this enables multiple packages to unambiguously set methods on those generics. Next: Diagnostic messages , Previous: Package namespaces , Up: Creating R packages [ Contents ][ Index ].
This section contains advice on writing packages to be used on multiple platforms or for distribution for example to be submitted to a package repository such as CRAN.
Portable packages should have simple file names: use only alphanumeric ASCII characters and period. Many of the graphics devices are platform-specific: even X11 aka x11 which although emulated on Windows may not be available on a Unix-alike and is not the preferred screen device on OS X.
It is rarely necessary for package code or examples to open a new device, but if essential, 68 use dev. R CMD check provides a basic set of checks, but often further problems emerge when people try to install and use packages submitted to CRAN — many of these involve compiled code. Here are some further checks that you can do to make your package more portable. Note that the -C flag for make is not included in the POSIX specification and is not implemented by some of the make s used with R.
which works in all versions of make known 71 to be used with R. and ensure that you use the value of environment variable MAKE and not just make in your scripts. On some platforms GNU make is available under a name such as gmake , and there SystemRequirements is used to set MAKE. If you only need GNU make for parts of the package which are rarely needed for example to create bibliography files under vignettes , use a file called GNUmakefile rather than Makefile as GNU make only will use the former.
macOS has used GNU make for many years it previously used BSD make , but the version has been frozen at 3. Since the only viable make for Windows is GNU make, it is permissible to use GNU extensions in files Makevars. win , Makevars. ucrt , Makefile.
Using test -e or [ -e ] in shell scripts is not fully portable 74 : -f is normally what is intended. Flags -a and -o are nowadays declared obsolescent by POSIX and should not be used. The -o flag for set in shell scripts is optional in POSIX and not supported on all the platforms R is used on. Although R only requires Fortran 90, gfortran does not have a way to specify that standard.
Not all common R platforms conform to the expected standards, e. C99 for C code. It is very rare to need to output such types, and bit integers can usually be converted to doubles for output. However, the C11 standard section 7.
h for example PRId64 so the portable approach is to test for these and if not available provide emulations in the package.
This can be used on other platforms with gcc or clang. If your package has a autoconf -generated configure script , try installing it whilst using this flag, and read through the config. log file — compilation warnings and errors can lead to features which are present not being detected. If possible do this on several platforms. although -pthread is pretty close to portable. Option -U is portable but little use on the command line as it will only cancel built-in defines not portable and those defined earlier on the command line R does not use any.
This is unsafe for several reasons. Second, future versions of compilers may behave differently including updates to quite old series so for example -Werror and specializations can make a package non-installable under a future version.
Third, using flags to suppress diagnostic messages can hide important information for debugging on a platform not tested by the package maintainer.
R CMD check can optionally report on unsafe flags which were used. For personal use -mtune is safer, but still not portable enough to be used in a public package. It is not safe to assume that long and pointer types are the same size, and they are not on bit Windows.
Next: Acknowledgements [ Contents ][ Index ]. Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one.
Permission is granted to copy and distribute translations of this manual into another language, under the above conditions for modified versions, except that this permission notice may be stated in a translation approved by the R Core Team.
Next: Creating R packages , Previous: Writing R Extensions , Up: Writing R Extensions [ Contents ][ Index ]. The contributions to early versions of this manual by Saikat DebRoy who wrote the first draft of a guide to using. Call and. Next: Writing R documentation files , Previous: Acknowledgements , Up: Writing R Extensions [ Contents ][ Index ]. Packages provide a mechanism for loading optional code, data and documentation as needed. The R distribution itself includes about 30 packages.
In the following, we assume that you know the library command, including its lib. loc argument, and we also assume basic knowledge of the R CMD INSTALL utility.
Once a source package is created, it must be installed by the command R CMD INSTALL. See Add-on-packages in R Installation and Administration. Other types of extensions are supported but rare : See Package types.
Some notes on terminology complete this introduction. These will help with the reading of this manual, and also in describing concepts accurately when asking for help.
A package is a directory of files which extend R, a source package the master files of a package , or a tarball containing the files of a source package, or an installed package, the result of running R CMD INSTALL on a source package. On some platforms notably macOS and Windows there are also binary packages , a zip file or tarball containing the files of an installed package which can be unpacked rather than installing from sources.
A package is not 1 a library. The latter is used in two senses in R documentation. The concept of lazy loading of code or data is mentioned at several points.
This is part of the installation, always selected for R code but optional for data. When used the R objects of the package are created at installation time and stored in a database in the R directory of the installed package, being loaded into the session at first use.
This makes the R session start up faster and use less virtual memory. For technical details, see Lazy loading in R Internals. CRAN is a network of WWW sites holding the R distributions and contributed code, especially R packages.
shtml submitting. Next: Configure and cleanup , Previous: Creating R packages , Up: Creating R packages [ Contents ][ Index ]. The package subdirectory may also contain files INDEX , configure , cleanup , LICENSE , LICENCE and NEWS. md 2 , or ChangeLog will be ignored by R, but may be useful to end users.
The utility R CMD build may add files in a build directory but this should not be used for other purposes. The NAMESPACE file is described in the section on Package namespaces. The optional files configure and cleanup are Bourne shell scripts which are, respectively, executed before and if option --clean was given after installation on Unix-alikes, see Configure and cleanup.
The analogues on Windows are configure. win and cleanup. Since R 4. ucrt and cleanup. ucrt are supported and take precedence over configure. They can hence be used to provide content specific for UCRT or Rtools42, if needed, but the support for. ucrt files may be removed in the future when building packages from source on the older versions of R will no longer be needed, and hence the files may be renamed back to. html Documentation. The package subdirectory should be given the same name as the package.
Because some file systems e. For example, if you have a package named foo , do not also create a package named Foo. Also, file names in the same directory must not differ only by case see the previous paragraph. For maximal portability filenames should only contain only ASCII characters not excluded already that is A-Za-z In addition, packages are normally distributed as tarballs, and these have a limit on path lengths: for maximal portability bytes.
A source package if possible should not contain binary executable files: they are not portable, and a security risk if they are of the appropriate architecture. R CMD check will warn about them 4 unless they are listed one filepath per line in a file BinaryFiles at the top level of the package. Note that CRAN will not accept submissions containing binary files even if they are listed. The R function package. skeleton can help to create the structure for a new package: see its help page for details.
Next: Licensing , Previous: Package structure , Up: Package structure [ Contents ][ Index ]. Fields start with an ASCII name immediately followed by a colon: the value starts after the colon and a space. Continuation lines for example, for descriptions longer than one line start with a space or tab. Field names are case-sensitive: all those used by R are capitalized. This should contain only ASCII letters, numbers and dot, have at least two characters and start with a letter and not end in a dot.
It is not a decimal number, so for example 0. Some package listings may truncate the title to 65 characters. It should use title case that is, use capitals for the principal words: tools::toTitleCase can help you with this , not use any markup, not have any continuation lines, and not end in a period unless part of …. Do not repeat the package name: it is often used prefixed by the name. Refer to other packages and external software in single quotes, and to book titles and similar in double quotes.
One can use several complete sentences, but only one paragraph. It should be intelligible to all the intended readership e. for a CRAN package to all CRAN users. This field should also be used for explaining the package name if necessary. URLs should be enclosed in angle brackets, e. Note that all significant contributors must be included: if you wrote an R wrapper for the work of others included in the src directory, you are not the sole and maybe not even the main author.
It should not end in a period or comma. This field is what is reported by the maintainer function and used by bug. For a CRAN package it should be a person , not a mailing list and not a corporate entity: do ensure that it is valid and will remain valid for the lifetime of the package. Note that the display name the part before the address in angle brackets should be enclosed in double quotes if it contains non-alphanumeric characters such as comma or period.
The current standard, RFC , allows periods but RFC did not. person for more information. Note that no role is assumed by default. Auto-generated package citation information takes advantage of this specification. These URL s are converted to active hyperlinks in CRAN package listings.
See Specifying URLs. This URL will be used by bug. report instead of sending an email to the maintainer. Base and recommended packages i. These priorities must not be used by other packages. If present, the collate specification must list all R code files in the package taking possible OS-specific subdirectories into account, see Package subdirectories as a whitespace separated list of file paths relative to the R subdirectory.
Paths containing white space or quotes need to be quoted. This can be overridden by installing with flag --no-byte-compile. This can be overridden by the flags --use-LTO and --no-use-LTO. This field was introduced in R 3.
This should only be used exceptionally, for example if the PDFs include large figures which are not part of the package sources and hence only in packages which do not have an Open Source license. The utils package is always implicitly appended. See Non-Sweave vignettes for details. Rd files. The examples are assumed to be in this encoding when running R CMD check , and it is used for the encoding of the CITATION file.
Only encoding names latin1 , latin2 and UTF-8 are known to be portable. Do not specify an encoding unless one is actually needed: doing so makes the package less portable. If a package has a specified encoding, you should run R CMD build etc in a locale using that encoding. This is used by install. html ; the former refers to the version. The subject classifications should be comma-separated lists of the respective classification codes, e.
WebThis option creates a single longer image, by joining all the current images in sequence top-to-bottom. Use +append to stack images left-to-right. If they are not of the same width, narrower images are padded with the current -background color setting, and their position relative to each other can be controlled by the current -gravity setting WebApple Footer The following purchases with Apple Card are ineligible to earn 5% back: monthly financing through Apple Card Monthly Installments, Apple iPhone Payments, the iPhone Upgrade Program, and wireless carrier financing plans; Apple Media Services; AppleCare+ monthly payments. Subject to credit approval. Valid only on qualifying Web21/09/ · Generally, a download manager enables downloading of large files or multiples files in one session. Many web browsers, such as Internet Explorer 9, include a download manager WebThe Business Journals features local business news from plus cities across the nation. We also provide tools to help businesses grow, network and hire Web14/12/ · ITPro Today’s Top 10 Stories About Microsoft in Dec 16, Highlights from Microsoft this year included its launch of Viva Combat IT Talent Shortage with Upskilling and Reskilling. Dec 16, Organizations should look to upskilling and reskilling their Why IT Operations Management is Critical- and Where to Start WebPresidential politics and political news from blogger.com News about political parties, political campaigns, world and international politics, politics news headlines plus in-depth features and ... read more
subnormal positive double. There is no default. The hue argument causes a "rotation" of the colors within the image by the amount specified. By default, objects e. When writing a JNG file, specify Zip compression to request that the alpha channel be encoded in PNG "IDAT" format, or JPEG to request that it be encoded in JPG "JDAA" format.It will be serialized to the wire, double top binary option. See the -annotate option for another convenient way to annotate an image with text. The principal function of noise peak elimination filter is to smooth the objects within an image without losing edge information and without creating undesired structures. This field was introduced in R 3. A larger value means that farther pixels influence each other as long as their colors are close enough see intensity-sigma. The performance of OpenMP varies substantially between platforms. Buy Learn more View in AR.