I think this may be an issue of interpretation about what is the desired result.  The code in print.m that handles the -F options is

        if (! isempty (opts.fontsize))
          ## Changing all fontsizes to a fixed value
          if (ischar (opts.fontsize))
            fontsize = str2double (opts.fontsize);
          else
            fontsize = opts.fontsize;
          endif
          if (do_scalefontsize)
            ## This is done to work around the bbox being whole numbers.
            fontsize *= opts.scalefontsize;
          endif

Instead of assigning the fontsize as given by the -F option, it applies a scaled version so that if you change the sizing with -S option things don't look weird.

As an example, try

print('fig2.svg','-dsvg',['-S' num2str(pos(3)/4) ',' num2str(pos(4))],'-F:18');

This uses 1/4 of the x-dimension and produces a narrow, but tall, plot which is attached as fig2.orig.svg.  Note that the plot labels have been scaled so that the plot still looks reasonable.

I disabled font scaling and then made the same squished plot.  It is attached as fig2.new.svg.  I prefer the look of existing code.


(file #50197, file #50198)

For completeness, I can this test

pos = [300 200 560 420];
figure(1,'paperunits','points', 'paperposition', [0,0,pos(3:4)])
plot([0,1],[0,1]);
set(gca,'fontunits','points','fontsize',18,'FontName','Arial');
print('fig1.svg','-dsvg', '-F:14');

This results in an SVG file where the font is 14 points.  Hence, there is only once combination of options that is incorrect.

I think most of this is actually correct.

First, the "papersize" property is only used for printing to page-like formats (PostScript, PDF).  Try 'help print' to see all of the options and caveats for printing.  For all other formats, the size is taken from the "paperposition" property.  Hence, the creation of the figure needs to be

figure(1,'paperunits','points', 'paperposition', [0,0,pos(3:4)])

If I run the rest of the test script after making the modification above I find that fig1.svg is indeed 560x420 as measured in points.  The fontsize is 18.

The size of fig1.png is 1166x875 pixels.  This also makes sense.  There are 72 points/inch so 560 points is 7.7778 inches.  The resolution for bitmapped formats, like png, is 150 dpi/inch so multiplying 7.7778 by 150 = 1166.  See the "-r" resolution option for print to change this default.

The "-S" option overrides the default mechanism above.  For fig2.png, the result is 560x420 pixels and for fig2.svg the result is 560x420 points.

The one thing I don't quite understand is that for fig2.svg the size of the font is 17.496 points instead of 18.0 points.  If there is a problem, it is with this one part of the svg file.