[R] multiple pages of plot in one image file

[Marc Schwartz]

On May 24, 2010, at 2:32 PM, array chip wrote:

> Hi, is there a way to create one image file (like using win.metafile(), bmp(), etc) that contained multiple pages of plots, just like what postscript() does in creating PDF file?
> 
> Thanks
> 
> John

John,

There is no notion of pages with bitmapped graphics as there is with PDF/PS, where you can have multiple separate plots in a single file. The single bitmapped file is designed to be rendered on a single bitmapped display device. The EMF/WMF metafiles on Windows are, I believe, subject to the same limitations, even though they are vector based.

However, you can output multiple plots to multiple files (one-to-one) after a single call to one of the bitmapped device functions. See the 'filename' argument in the various functions (eg. ?png) where you can use a filename format that includes a sprintf style integer format, such as "MyPlots%03d.png". The "%03d" will start as '001' and increment with each new plot() call before the subsequent dev.off() call.

For example:

png(file = "test%03d.png")
barplot(1:5)
barplot(1:10)
barplot(1:15)
dev.off()

You end up with three files named test001.png, test002.png and test003.png.

HTH,

Marc Schwartz