| % File src/library/grDevices/man/dev2bitmap.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2018 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{dev2bitmap} |
| \alias{dev2bitmap} |
| \alias{bitmap} |
| |
| \title{Graphics Device for Bitmap Files via Ghostscript} |
| \usage{ |
| bitmap(file, type = "png16m", height = 7, width = 7, res = 72, |
| units = "in", pointsize, taa = NA, gaa = NA, \dots) |
| |
| dev2bitmap(file, type = "png16m", height = 7, width = 7, res = 72, |
| units = "in", pointsize, \dots, |
| method = c("postscript", "pdf"), taa = NA, gaa = NA) |
| } |
| \arguments{ |
| \item{file}{The output file name, with an appropriate extension.} |
| \item{type}{The type of bitmap.} |
| \item{width, height}{Dimensions of the display region.} |
| \item{res}{Resolution, in dots per inch.} |
| \item{units}{The units in which \code{height} and \code{width} are |
| given. Can be \code{in} (inches), \code{px} (pixels), \code{cm} or |
| \code{mm}.} |
| \item{pointsize}{The pointsize to be used for text: defaults to |
| something reasonable given the width and height} |
| \item{\dots}{Other parameters passed to \code{\link{postscript}} or |
| \code{\link{pdf}}.} |
| \item{method}{Should the plot be done by \code{\link{postscript}} or |
| \code{\link{pdf}}?} |
| \item{taa, gaa}{Number of bits of antialiasing for text and for graphics |
| respectively. Usually 4 (for best effect) or 2. Not supported on |
| all types.} |
| } |
| \description{ |
| \code{bitmap} generates a graphics file. |
| \code{dev2bitmap} copies the current graphics device to a file in a |
| graphics format. |
| } |
| \details{ |
| \code{dev2bitmap} works by copying the current device to a |
| \code{\link{postscript}} or \code{\link{pdf}} device, and |
| post-processing the output file using \code{ghostscript}. |
| \code{bitmap} works in the same way using a \code{postscript} device |
| and post-processing the output as \sQuote{printing}. |
| |
| You will need \code{ghostscript}: the full path to the executable can |
| be set by the environment variable \env{R_GSCMD}. If this is unset, a |
| GhostScript executable will be looked for by name on your path: on a |
| Unix alike \code{"gs"} is used, and on Windows the setting of the |
| environment variable \env{GSC} is used, otherwise commands |
| \code{"gswi64c.exe"} then \code{"gswin32c.exe"} are tried. |
| |
| The types available will depend on the version of \code{ghostscript}, |
| but are likely to include |
| \code{"jpeg"}, \code{"jpegcmyk"}, \code{"jpeggray"}, |
| \code{"tiffcrle"}, \code{"tiffg3"}, |
| \code{"tiffg32d"}, \code{"tiffg4"}, \code{"tiffgray"}, \code{"tifflzw"}, |
| \code{"tiffpack"}, \code{"tiff12nc"}, \code{"tiff24nc"}, \code{"tiff32nc"} |
| \code{"png16"}, \code{"png16m"}, \code{"png256"}, \code{"png48"}, |
| \code{"pngmono"}, \code{"pnggray"}, \code{"pngalpha"}, |
| \code{"bmp16"}, \code{"bmp16m"} \code{"bmp256"}, \code{"bmp32b"}, |
| \code{"bmpgray"}, \code{"bmpmono"}. |
| |
| The default type, \code{"png16m"}, supports 24-bit colour and |
| anti-aliasing. Type \code{"png256"} uses a palette of 256 colours and |
| could give a more compact representation. Monochrome graphs can use |
| \code{"pngmono"}, or \code{"pnggray"} if anti-aliasing is desired. |
| Plots with a transparent background and varying degrees of |
| transparency should use \code{"pngalpha"}. |
| |
| Note that for a colour TIFF image you probably want \code{"tiff24nc"}, |
| which is 8-bit per channel RGB (the most common TIFF format). None of |
| the listed TIFF types support transparency. \code{"tiff32nc"} uses |
| 8-bit per channel CMYK, which printers might require. |
| |
| For formats which contain a single image, a file specification like |
| \code{Rplots\%03d.png} can be used: this is interpreted by Ghostscript. |
| |
| For \code{dev2bitmap} if just one of \code{width} and \code{height} is |
| specified, the other is chosen to preserve the aspect ratio of the |
| device being copied. The main reason to prefer \code{method = "pdf"} |
| over the default would be to allow semi-transparent colours to be used. |
| |
| For graphics parameters such as \code{"cra"} that need to work in |
| pixels, the default resolution of 72dpi is always used. |
| |
| On Windows only, |
| paths for \code{file} and \env{R_GSCMD} which contain spaces are |
| mapped to short names \emph{via} \code{\link{shortPathName}}. |
| } |
| \value{ |
| None. |
| } |
| |
| \note{ |
| On Windows, |
| Use of \code{bitmap} will leave a temporary file (with file name |
| starting \code{Rbit}). |
| |
| Although using \code{type = "pdfwrite"} will work for simple plots, it |
| is not recommended. Either use \code{\link{pdf}} to produce PDF |
| directly, or call \command{ps2pdf -dAutoRotatePages=/None} on the |
| output of \code{\link{postscript}}: that command is optimized to do |
| the conversion to PDF in ways that these functions are not. |
| } |
| |
| \section{Conventions}{ |
| This section describes the implementation of the conventions for |
| graphics devices set out in the \dQuote{R Internals Manual}. These |
| devices follow the underlying device, so when viewed at the stated |
| \code{res}: |
| |
| \itemize{ |
| \item The default device size is 7 inches square. |
| \item Font sizes are in big points. |
| \item The default font family is (for the standard Ghostscript |
| setup) URW Nimbus Sans. |
| \item Line widths are as a multiple of 1/96 inch, with no minimum. |
| \item Circle of any radius are allowed. |
| \item Colours are interpreted by the viewing/printing application. |
| } |
| } |
| |
| \seealso{ |
| \code{\link{savePlot}}, which for \code{windows} and |
| \code{X11(type = "cairo")} provides a simple way to record a PNG |
| record of the current plot. |
| |
| \code{\link{postscript}}, \code{\link{pdf}}, \code{\link{png}}, |
| \code{\link{jpeg}}, \code{\link{tiff}} and \code{bmp}. |
| |
| To display an array of data, see \code{\link{image}}. |
| } |
| |
| \keyword{utilities} |