Let us say I have a plot, for example that one:
and I would like to export it as a PDF in such a way that if I print the PDF in a A4 format (for instance), 1 "unit" on the plot will correspond to 1cm on the A4. So the $x$-axis above should measure exactly 5cm when printed on an A4. The curve can be rasterized.
Is there an accurate and robust way to do this?
PS: This can be useful if you want to print a map at a given scale, or plans, etc.