dev2bitmap {grDevices}R Documentation

Graphics Device for Bitmap Files via GhostScript

Description

bitmap generates a graphics file. dev2bitmap copies the current graphics device to a file in a graphics format.

Usage

bitmap(file, type = "png256", height = 6, width = 6, res = 72,
       units = "in", pointsize, ...)

dev2bitmap(file, type = "png256", height = 6, width = 6, res = 72,
           units = "in", pointsize, ...,
           method = c("postscript", "pdf"))

Arguments

file The output file name, with an appropriate extension.
type The type of bitmap. the default is "png256".
width, height Dimensions of the display region.
res Resolution, in dots per inch.
units The units in which height and width are given. Can be in (inches), px (pixels), cm or mm.
pointsize The pointsize to be used for text: defaults to something reasonable given the width and height
... Other parameters passed to postscript or pdf.
method Should the plot be done by postscript or pdf?

Details

dev2bitmap works by copying the current device to a postscript or pdf device, and post-processing the output file using ghostscript. bitmap works in the same way using a postscript device and post-processing the output as ‘printing’.

You will need ghostscript: the full path to the executable can be set by the environment variable R_GSCMD. (If this is unset the command "gs" is used, which will work if it is in your path.)

The types available will depend on the version of ghostscript, but are likely to include "pcxmono", "pcxgray", "pcx16", "pcx256", "pcx24b", "pcxcmyk", "pbm", "pbmraw", "pgm", "pgmraw", "pgnm", "pgnmraw", "pnm", "pnmraw", "ppm", "ppmraw", "pkm", "pkmraw", "tiffcrle", "tiffg3", "tiffg32d", "tiffg4", "tifflzw", "tiffpack", "tiff12nc", "tiff24nc", "psmono", "psgray", "psrgb", "bit", "bitrgb", "bitcmyk", "pngmono", "pnggray", "png16", "png256", "png16m", "jpeg", "jpeggray", "pdfwrite".

For formats which contain a single image, a file specification like Rplots%03d.png can be used: this is interpreted by GhostScript.

For dev2bitmap if just one of width and height is specified, the other is chosen to preserve aspect ratio of the device being copied. The main reason to prefer method = "pdf" over the default would be to allow semi-transparent colours to be used.

For graphics parameters such as "cra" that need to work in pixels, the default resolution of 72dpi is always used.

Value

None.

See Also

postscript, pdf, png and jpeg and on Windows bmp.

To display an array of data, see image.


[Package grDevices version 2.6.2 Index]