Question

I am exporting some plots to EPS files. My code is

setEPS()
postscript("test.eps")
par(mar=c(0,0,0,0))
plot(1:10)
dev.off()

But I find that there are (device) margins around the plotting area. How to remove them? Thank you.

Answer 1

That isn’t a margin. Notice how there are no axes, tick marks or plot frame in the EPS produced by your code. There is no room to draw these and the plot frame will be exactly on the edge of the EPS.

What you are seeing is the extra padding that R adds to the axis limits to ensure that the plotting characters are inside the plot region, not on it’s edge. IIRC this padding is 4%.

You can turn this off using using the xaxs and yaxs plotting parameters for the x- and y-axis respectively; see ?par

 ‘xaxs’ The style of axis interval calculation to be used for the
      x-axis.  Possible values are ‘"r"’, ‘"i"’, ‘"e"’, ‘"s"’,
      ‘"d"’.  The styles are generally controlled by the range of
      data or ‘xlim’, if given.
      Style ‘"r"’ (regular) first extends the data range by 4
      percent at each end and then finds an axis with pretty labels
      that fits within the extended range.
      Style ‘"i"’ (internal) just finds an axis with pretty labels
      that fits within the original data range.
      ** editted for brevity **
      (_Only ‘"r"’ and ‘"i"’ styles have been implemented in R._)

The default is "r", instead use:

setEPS()
postscript("test.eps")
par(mar=c(0,0,0,0), xaxs = "i", yaxs = "i")
plot(1:10)
dev.off()