| postscript {grDevices} | R Documentation |
postscript starts the graphics device driver for producing
PostScript graphics.
The auxiliary function ps.options can be used to set and view
(if called without arguments) default values for the arguments to
postscript.
postscript(file = ifelse(onefile, "Rplots.ps", "Rplot%03d.ps"),
onefile = TRUE,
paper, family, encoding, bg, fg,
width, height, horizontal, pointsize,
pagecentre, print.it, command,
title = "R Graphics Output", fonts = NULL)
ps.options(paper, horizontal, width, height, family, encoding,
pointsize, bg, fg,
onefile = TRUE, print.it = FALSE, append = FALSE,
reset = FALSE, override.check = FALSE)
file |
a character string giving the name of the file. If it is
"", the output is piped to the command given by the argument
command.
If it is of the form "|cmd", the output is piped to the
command given by ‘cmd’.
For use with onefile = FALSE give a printf format such
as "Rplot%03d.ps" (the default in that case).
|
paper |
the size of paper in the printer. The choices are
"a4", "letter", "legal" and
"executive" (and these can be capitalized).
Also, "special" can be used, when the width
and height specify the paper size. A further choice is
"default", which is the default. If this is selected, the
papersize is taken from the option "papersize"
if that is set and to "a4" if it is unset or empty. |
horizontal |
the orientation of the printed image, a logical. Defaults to true, that is landscape orientation on paper sizes with width less than height. |
width, height |
the width and height of the graphics region in inches. The default is to use the entire page less a 0.25 inch border on each side. |
family |
the font family to be used. EITHER a single character string OR a character vector of length four or five. See the section ‘Families’. |
encoding |
the name of an encoding file. Defaults to
"ISOLatin1.enc"
in the ‘afm’ directory of package grDevices, which is used
if the path does not contain a path separator. An extension
".enc" can be omitted.
In a UTF-8 locale only "ISOLatin1.enc" is allowed.
|
pointsize |
the default point size to be used. |
bg |
the default background color to be used.
If "transparent" (or an equivalent specification), no
background is painted. |
fg |
the default foreground color to be used. |
onefile |
logical: if true (the default) allow multiple figures
in one file. If false, generate a file name containing the page
number and use an EPSF header and no DocumentMedia comment. |
pagecentre |
logical: should the device region be centred on the page? – defaults to true. |
print.it |
logical: should the file be printed when the device is
closed? (This only applies if file is a real file name.) |
command |
the command to be used for “printing”. Defaults to
option "printcmd"; this can also be selected as
"default". |
append |
logical; currently disregarded; just there for compatibility reasons. |
reset, override.check |
logical arguments passed to
check.options. See the Examples. |
title |
title string to embed in the file. |
fonts |
a character vector specifying R graphics (device-independent) font family names for fonts which must be included in the PostScript file. |
postscript opens the file file and the PostScript
commands needed to plot any graphics requested are stored in that
file. This file can then be printed on a suitable device to obtain
hard copy.
A postscript plot can be printed via postscript in two ways.
print.it = TRUE causes the command given in
argument command to be called with argument "file"
when the device is closed.
Note that the plot file is not deleted unless command arranges to
delete it.
file="" or file="|cmd" can be used to print
using a pipe on systems that support ‘popen’. Failure to open the
command will probably be reported to the terminal but not to
‘popen’, in which case close the device by dev.off
immediately.
The file argument is interpreted as a C integer format as used
by sprintf, with integer argument the page number.
The default gives files ‘Rplot001.ps’, ..., ‘Rplot999.ps’,
‘Rplot1000.ps’, ....
The postscript produced by R is EPS (Encapsulated PostScript)
compatible, and can be included into other documents, e.g., into
LaTeX, using \includegraphics{<filename>}. For use in this way
you will probably want to set horizontal = FALSE, onefile = FALSE,
paper = "special".
Most of the PostScript prologue used is taken from the R character
vector .ps.prolog. This is marked in the output, and can be
changed by changing that vector. (This is only advisable for
PostScript experts: the standard version is in
namespace:grDevices.)
ps.options needs to be called before calling postscript,
and the default values it sets can be overridden by supplying
arguments to postscript.
A PostScript device has a default font, which can be set by the user
via family. If other fonts are to be used when drawing to
the PostScript device, these must be declared when the
device is created via fonts; the font family names for this
argument are device-independent R graphics font family names (see the
documentation for postscriptFonts).
Line widths as controlled by par(lwd=) are in multiples of
1/96 inch. Multiples less than 1 are allowed. pch="." with
cex = 1 corresponds to a square of side 1/72 inch.
Font families may be specified in several ways. The family
argument specifies an initial/default font family for the device.
This is a PostScript-specific font family specification (see below).
The fonts argument specifies a set of device-independent
font families that are mapped to PostScript-specific fonts via
a font database (see postscriptFonts).
The argument family specifies the initial/default font family
to be used. In normal use it is one of "AvantGarde",
"Bookman", "Courier", "Helvetica",
"Helvetica-Narrow", "NewCenturySchoolbook",
"Palatino" or "Times", and refers to the standard Adobe
PostScript fonts families of those names which are included (or
cloned) in all common PostScript devices.
Many PostScript emulators (including those based on
ghostscript) use the URW equivalents of these fonts, which are
"URWGothic", "URWBookman", "NimbusMon",
"NimbusSan", "NimbusSanCond", "CenturySch",
"URWPalladio" and "NimbusRom" respectively. If your
PostScript device is using URW fonts, you will obtain access to more
characters and more appropriate metrics by using these names. To make
these easier to remember, "URWHelvetica" == "NimbusSan" and
"URWTimes" == "NimbusRom" are also supported.
If the second form of argument "family" is used, it should be a
character vector of four or five paths to Adobe Font Metric files for
the regular, bold, italic, bold italic and (optionally) symbol fonts to
be used. If these paths do not contain the file separator, they are
taken to refer to files in directory ‘afm’ of package
grDevices. Thus the default Helvetica family can be specified by
family =
c("hv______.afm",
"hvb_____.afm", "hvo_____.afm", "hvbo____.afm", "sy______.afm").
It is the user's responsibility to check that suitable fonts are made
available, and that they contain the needed characters when
re-encoded. The fontnames used are taken from the FontName
fields of the afm files. The software including the PostScript plot
file should either embed the font outlines (usually from ‘.pfb’
or ‘.pfa’ files) or use DSC comments to instruct the print
spooler to do so.
The .afm files for the first four fonts do not need to be in
the correct encoding, but that for the symbol font must be.
It is also possible to specify family = "ComputerModern" with
an appropriate encoding (see below). This is intended to use with the
Type 1 versions of the TeX CM fonts. It will normally be possible to
include such output in TeX or LaTeX provided it is processed with
dvips -Ppfb -j0 or the equivalent on your system. (-j0
turns off font subsetting.) When family = "ComputerModern" is
used, the italic/bold-italic fonts used are slanted fonts
(cmsl10 and cmbxsl10). To use text italic fonts
instead, use family = c("CM_regular_10.afm", "CM_boldx_10.afm",
"cmti10.afm", "cmbxti10.afm", "CM_symbol_10.afm").
Encodings describe which glyphs are used to display the character codes
(in the range 0–255). By default R uses ISOLatin1 encoding, and
the examples for text are in that encoding. However,
the encoding used on machines running R may well be different, and by
using the encoding argument the glyphs can be matched to
encoding in use.
None of this will matter if only ASCII characters (codes 32–126) are
used as all the encodings (except "TeXtext") agree over that
range. Some encodings are supersets of ISOLatin1, too. However, if
accented and special characters do not come out as you expect, you may
need to change the encoding. Some other encodings are supplied with
R: "WinAnsi.enc" and "MacRoman.enc" correspond to the
encodings normally used on Windows and Classic MacOS (at least by
Adobe), and "PDFDoc.enc" is the first 256 characters of the
Unicode encoding, the standard for PDF. There are also encodings
"ISOLatin2.enc", "CP1250.enc", "ISOLatin7.enc"
(ISO 8859-13) and "ISOLatin9.enc" (ISO 8859-15),
"Cyrillic.enc" (ISO 8859-5), "KOI8-R.enc",
"KOI8-U.enc", "CP1251.enc", and "TeXtext" for the
7-bit TeX encoding. Note that many glyphs in these encodings are not
in the fonts corresponding to the standard families: the Adobe ones
cover little more than Latin-1, whereas the URW ones also cover
Latin-2, Latin-7, Latin-9 and Cyrillic.
If you change the encoding, it is your responsibility to ensure that the PostScript font contains the glyphs used. One issue here is the Euro symbol which is in the WinAnsi and MacRoman encodings but may well not be in the PostScript fonts. (It is in the URW variants; it is not in the supplied Adobe Font Metric files.)
There is an exception. Character 45 ("-") is always set
as minus (its value in Adobe ISOLatin1) even though it is hyphen in
the other encodings. Hyphen is available as character 173 (octal
0255) in all the Latin encodings and Cyrillic. There are some
discrepancies in accounts of glyphs 39 and 96: the supplied encodings
(except CP1250 and CP1251) treat these as ‘quoteright’ and
‘quoteleft’ (rather than ‘quotesingle’/‘acute’
and ‘grave’ respectively), as they are in the Adobe
documentation.
Computer Modern fonts are encoded rather differently and should be
used with encoding = "TeXtext.enc", taking care that the
symbols < > \ _ { } are not available in those fonts.
Support for Computer Modern fonts is based on a contribution by Brian D'Urso durso@hussle.harvard.edu.
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.
postscriptFonts,
Devices,
{check.options which is called from both
ps.options and postscript}.
## Not run:
# open the file "foo.ps" for graphics output
postscript("foo.ps")
# produce the desired graph(s)
dev.off() # turn off the postscript device
postscript("|lp -dlw")
# produce the desired graph(s)
dev.off() # plot will appear on printer
# for URW PostScript devices
postscript("foo.ps", family = "NimbusSan")
## for inclusion in Computer Modern TeX documents, perhaps
postscript("cm_test.eps", width = 4.0, height = 3.0,
horizontal = FALSE, onefile = FALSE, paper = "special",
family = "ComputerModern", encoding = "TeXtext.enc")
## The resultant postscript file can be used by dvips -Ppfb -j0.
## To test out encodings, you can use
TestChars <- function(encoding="ISOLatin1", family="URWHelvetica")
{
postscript(encoding=encoding, family=family)
par(pty="s")
plot(c(-1,16), c(-1,16), type="n", xlab="", ylab="", xaxs="i", yaxs="i")
title(paste("Centred chars in encoding", encoding))
grid(17, 17, lty=1)
for(i in c(32:255)) {
x <- i %% 16
y <- i %/% 16
points(x, y, pch=i)
}
dev.off()
}
## there will be many warnings. We use URW to get a complete enough
## set of font metrics.
TestChars()
TestChars("ISOLatin2")
TestChars("WinAnsi")
## End(Not run)
ps.options(bg = "pink")
utils::str(ps.options(reset = TRUE))
### ---- error checking of arguments: ----
ps.options(width=0:12, onefile=0, bg=pi)
# override the check for 'onefile', but not the others:
utils::str(ps.options(width=0:12, onefile=1, bg=pi,
override.check = c(FALSE,TRUE,FALSE)))