pdf {grDevices}R Documentation

PDF Graphics Device


pdf starts the graphics device driver for producing PDF graphics.


pdf(file = ifelse(onefile, "Rplots.pdf", "Rplot%03d.pdf"),
    width = 6, height = 6, onefile = TRUE, family = "Helvetica",
    title = "R Graphics Output", fonts = NULL, version = "1.1",
    paper = "special", encoding, bg, fg, pointsize, pagecentre)


file a character string giving the name of the file. 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.)
width, height the width and height of the graphics region in inches.
onefile logical: if true (the default) allow multiple figures in one file. If false, generate a file name containing the page number.
family the font family to be used, see postscript.
title title string to embed in the file.
fonts a character vector specifying R graphics font family names for fonts which will be included in the PDF file.
version 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.
paper 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 to "a4" if it is unset or empty.
encoding the name of an encoding file. See postscript for details.
bg the default background color to be used.
fg the default foreground color to be used.
pointsize the default point size to be used. Strictly speaking, in bp, that is 1/72 of an inch, but approximately in points.
pagecentre logical: should the device region be centred on the page? – defaults to true, but is only relevant for paper != "special".


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 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.)

R does not embed fonts in the PDF file though, so it is only possible straightforward to use mappings to the font families that are assumed to be available in any PDF viewer: "Times" (equivalently "serif"), "Helvetica" (equivalently "sans"), "Courier" (equivalently "mono") and "Symbol" (equivalently "symbol"). 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). The URW-based families described for postscript can be used with viewers such as GSView which are based on URW fonts.

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’.

pdf writes uncompressed PDF. It is primarily intended for producing PDF graphics for inclusion in other documents, and PDF-includers such as pdftex are usually able to handle compression.

At present the PDF is fairly simple, with each page being represented as a single stream. 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 1.4 for semitransparent output to be understood, and at least 1.3 if CID fonts are to be used: if these features are used the version number will be increased (with a warning). Specifying a low version number (as the default) is useful if you want to produce PDF output that can be viewed on older or non-Adobe PDF viewers. (PDF 1.4 requires Acrobat 5 or later.)

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".


Acrobat Reader does not use the fonts specified but rather emulates them from multiple-master fonts. This can be seen in imprecise centering of characters, for example the multiply and divide signs in Helvetica.

Acrobat Reader 5.x and later can be extended by support for Asian and (so-called) Central European fonts (the latter only for 7.x), and this will be needed for full use of encodings other than Latin-1. See http://www.adobe.com/products/acrobat/acrrasianfontpack.html.

See Also

pdfFonts, Devices, postscript


## Not run: 
## Test function for encodings
TestChars <- function(encoding="ISOLatin1", ...)
    pdf(encoding=encoding, ...)
    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)
## there will be many warnings.
## this does not view properly in older viewers.
TestChars("ISOLatin2", family="URWHelvetica")
## works well for viewing in gs-based viewers, and often in xpdf.
## End(Not run)

[Package grDevices version 2.5.0 Index]