When plots are not generated from R code, there is no way for knitr to
capture plots automatically. In this case, you may generate the images
manually and pass their file paths to this function to include them in the
output. The major advantage of using this function is that it is portable in
the sense that it works for all document formats that knitr supports,
so you do not need to think if you have to use, for example, LaTeX or
Markdown syntax, to embed an external image. Chunk options related to
graphics output that work for normal R plots also work for these images, such
include_graphics( path, auto_pdf = getOption("knitr.graphics.auto_pdf", FALSE), dpi = NULL, rel_path = getOption("knitr.graphics.rel_path", TRUE), error = getOption("knitr.graphics.error", TRUE) )
The same as the input character vector
path but it is marked
with special internal S3 classes so that knitr will convert the file
paths to proper output code according to the output format.
A character vector of image paths. Both local file paths and web
paths are supported. Note that the
are not supported for web paths.
Whether to use PDF images automatically when the output
format is LaTeX. If
TRUE, then e.g.
foo/bar.png will be
foo/bar.pdf if the latter exists. This can be useful
since normally PDF images are of higher quality than raster images like
PNG, when the output is LaTeX/PDF.
DPI (dots per inch) value. Used to calculate the output width (in
inches) of the images. This will be their actual width in pixels, divided
dpi. If not provided, the chunk option
dpi is used; if
NA, the output width will not be calculated.
Whether to automatically convert absolute paths to relative
paths. If you know for sure that absolute paths work, you may set this
argument or the global option
Whether to signal an error if any files specified in the
path argument do not exist and are not web resources.