| dev2bitmap {grDevices} | R Documentation |
bitmap generates a graphics file.
dev2bitmap copies the current graphics device to a file in a
graphics format.
bitmap(file, type = "png16m", height = 7, width = 7, res = 72,
units = "in", pointsize, taa = NA, gaa = NA, ...)
dev2bitmap(file, type = "png16m", height = 7, width = 7, res = 72,
units = "in", pointsize, ...,
method = c("postscript", "pdf"), taa = NA, gaa = NA)
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? |
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. |
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",
"pngalpha", "png16", "png256", "png16m",
"png48", "jpeg", "jpeggray", "pdfwrite".
The default type, "png16m" supports 24-bit colour and
anti-aliasing. Versions of R prior to 2.7.0 defaulted to
"png256", which uses a palette of 256 colours and could be a
more compact representation. Monochrome graphs can use
"pngmono", or "pnggray" if anti-aliasing is desired.
Note that for a colour TIFF image you probably want "tiff24nc",
which is 8-bit per channel RGB (the most common TIFF format). None of
the listed TIFF types support transparency.
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.
None.
This section describes the implementation of the conventions for
graphics devices set out in the “R Internals Manual”. These
devices follow the underlying device, so when viewed at the stated
res:
savePlot, which for windows and
X11(type = "Cairo") provides a simple way to record a PNG
record of the current plot.
postscript, pdf, png and
jpeg and on Windows bmp.
To display an array of data, see image.