pdf starts the graphics device driver for producing PDF
graphics.
pdf(file = if(onefile) "Rplots.pdf" else "Rplot%03d.pdf",
width, height, onefile, family, title, fonts, version,
paper, encoding, bg, fg, pointsize, pagecentre, colormodel,
useDingbats, useKerning, fillOddEven, compress)a character string giving the name of the file.
If it is of the form "|cmd", the output is piped to the
command given by cmd. If it is NULL,
then no external file is created (effectively, no drawing occurs),
but the device may still be queried (e.g., for size of text).
For use with onefile = FALSE give a C integer format such
as "Rplot%03d.pdf" (the default in that case).
(See postscript for further details.)
Tilde expansion (see path.expand) is done.
the width and height of the graphics region in
inches. The default values are 7.
logical: if true (the default) allow multiple figures
in one file. If false, generate a file with name containing the page
number for each page. Defaults to TRUE, and forced to true
if file is a pipe.
the font family to be used, see
postscript. Defaults to "Helvetica".
title string to embed as the /Title field in the
file. Defaults to "R Graphics Output".
a character vector specifying R graphics font family
names for additional fonts which will be included in the PDF file.
Defaults to NULL.
a string describing the PDF version that will be
required to view the output. This is a minimum, and will be
increased (with a warning) if necessary. Defaults to "1.4",
but see ‘Details’.
the target paper size. The choices are
"a4", "letter", "legal" (or "us") and
"executive" (and these can be capitalized), or "a4r"
and "USr" for rotated (‘landscape’).
The default is "special", which means that the width
and height specify the paper size. A further choice is
"default"; if this is selected, the
papersize is taken from the option "papersize"
if that is set and as "a4" if it is unset or empty.
Defaults to "special".
the name of an encoding file. See
postscript for details. Defaults to "default".
the initial background color to be used. Defaults to
"transparent".
the initial foreground color to be used. Defaults to
"black".
the default point size to be used. Strictly
speaking, in bp, that is 1/72 of an inch, but approximately in
points. Defaults to 12.
logical: should the device region be centred on the
page? -- is only relevant for paper != "special".
Defaults to TRUE.
a character string describing the color model:
currently allowed values are "srgb", "gray" (or
"grey") and "cmyk". Defaults to "srgb". See section
‘Color models’.
logical. Should small circles be rendered
via the Dingbats font? Defaults to TRUE, which produces
smaller and better output. Setting this to FALSE can work
around font display problems in broken PDF viewers: although this
font is one of the 14 guaranteed to be available in all PDF viewers,
that guarantee is not always honoured.
On Unix-alikes (incl. Mac), see the ‘Note’ for a possible fix for some viewers.
logical. Should kerning corrections be included in
setting text and calculating string widths? Defaults to TRUE.
logical controlling the polygon fill mode: see
polygon for details. Defaults to FALSE.
logical. Should PDF streams be generated with Flate
compression? Defaults to TRUE.
The default color model ("srgb") is sRGB. Model "gray"
(or "grey") maps sRGB colors to greyscale using perceived
luminosity (biased towards green). "cmyk" outputs in CMYK
colorspace. The simplest possible conversion from sRGB to CMYK is
used
(https://en.wikipedia.org/wiki/CMYK_color_model#Mapping_RGB_to_CMYK),
and raster images are output in RGB.
Also available for backwards compatibility is model "rgb" which
uses uncalibrated RGB and corresponds to the model used with that name
in R prior to 2.13.0. Some viewers may render some plots in that
colorspace faster than in sRGB, and the plot files will be smaller.
This section describes the implementation of the conventions for graphics devices set out in the “R Internals Manual”.
The default device size is 7 inches square.
Font sizes are in big points.
The default font family is Helvetica.
Line widths are as a multiple of 1/96 inch, with a minimum of 0.01 enforced.
Circles of any radius are allowed. Unless useDingbats =
FALSE, opaque circles of less than 10 big points radius are
rendered using char 108 in the Dingbats font: all semi-transparent
and larger circles using a B<U+00E9>zier curve for each
quadrant.
Colours are by default specified as sRGB.
At very small line widths, the line type may be forced to solid.
Except on Windows it is possible to print directly from pdf by
something like (this is appropriate for a CUPS printing system):
pdf("|lp -o landscape", paper = "a4r")This forces onefile = TRUE.
All arguments except file default to values given by
pdf.options(). The ultimate defaults are quoted in the
arguments section.
pdf() opens the file file and the PDF commands needed to
plot any graphics requested are sent to that file.
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.pdf, …, Rplot999.pdf,
Rplot1000.pdf, ….
The family argument can be used to specify a PDF-specific
font family as the initial/default font for the device. If additional
font families are to be used they should be included in the
fonts argument.
If a device-independent R graphics font family is specified (e.g., via
par(family = ) in the graphics package), the PDF device makes use
of the PostScript font mappings to convert the R graphics font family
to a PDF-specific font family description. (See the
documentation for pdfFonts.)
This device does not embed fonts in the PDF file, so it is only
straightforward to use mappings to the font families that can be
assumed to be available in any PDF viewer: "Times"
(equivalently "serif"), "Helvetica" (equivalently
"sans") and "Courier" (equivalently "mono").
Other families may be specified, but it is the user's responsibility
to ensure that these fonts are available on the system and third-party
software (e.g., Ghostscript) may be required to embed the fonts so
that the PDF can be included in other documents (e.g., LaTeX): see
embedFonts. The URW-based families described for
postscript can be used with viewers, platform dependently:
viewers set up to use URW fonts, which is
usual with those based on xpdf or Ghostscript.
viewers such as GSView which utilise URW fonts.
Since embedFonts makes use of Ghostscript, it should be
able to embed the URW-based families for use with other viewers.
See postscript for details of encodings, as the internal
code is shared between the drivers. The native PDF encoding is given
in file PDFDoc.enc.
The PDF produced is fairly simple, with each page being represented as a single stream (by default compressed and possibly with references to raster images). The R graphics model does not distinguish graphics objects at the level of the driver interface.
The version argument declares the version of PDF that gets
produced. The version must be at least 1.2 when compression is used,
1.4 for semi-transparent output to be understood, and at least 1.3 if
CID fonts are to be used: if any of these features are used the
version number will be increased (with a warning). (PDF 1.4 was first
supported by Acrobat 5 in 2001; it is very unlikely not to be
supported in a current viewer.)
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, which is
also the ‘pixel’ size assumed for graphics parameters such as
"cra".
The paper argument sets the /MediaBox entry in the file,
which defaults to width by height. If it is set to
something other than "special", a device region of the
specified size is (by default) centred on the rectangle given by the
paper size: if either width or height is less
than 0.1 or too large to give a total margin of 0.5 inch, it is
reset to the corresponding paper dimension minus 0.5. Thus if you
want the default behaviour of postscript use
pdf(paper = "a4r", width = 0, height = 0) to centre the device region
on a landscape A4 page with 0.25 inch margins.
When the background colour is fully transparent (as is the initial default value), the PDF produced does not paint the background. Most PDF viewers will use a white canvas so the visual effect is if the background were white. This will not be the case when printing onto coloured paper, though.
pdfFonts, pdf.options,
embedFonts,
Devices,
postscript.
cairo_pdf and (on macOS only) quartz
for other devices that can produce PDF.
More details of font families and encodings and especially handling text in a non-Latin-1 encoding and embedding fonts can be found in
Paul Murrell and Brian Ripley (2006) Non-standard fonts in PostScript and PDF graphics. R News, 6(2):41--47. https://www.r-project.org/doc/Rnews/Rnews_2006-2.pdf.
# NOT RUN {
## Test function for encodings
TestChars <- function(encoding = "ISOLatin1", ...)
{
pdf(encoding = encoding, ...)
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.
TestChars("ISOLatin2")
## this does not view properly in older viewers.
TestChars("ISOLatin2", family = "URWHelvetica")
## works well for viewing in gs-based viewers, and often in xpdf.
# }
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