Re: empty data-files

[Ethan M. <merritt@u.washington.edu>]

On Thursday 13 January 2005 07:53 am, Petr Mikulik wrote:
> >
> > So I think that in plot2d.c:
> >
> > int_error(c_token, "no valid data points found in specified file");
> >
> > should be replaced with:
> >
> > int_warn(c_token, "no valid data points found in specified file");
> 
> This behviour is fine with me, just there should be an int_error("nothing to
> plot") if there was only a single (empty) file to plot. Please update your
> patch, add taking care of 3d plots.

It's more complicated that that.  The first thing that will happen
if you just change int_error into int_warn is likely to be a 
divide-by-zero error as the autoscaling fails.  Beyond that, there
is the question of consistent behaviour of the plot.
For instance, "skipping" a plot  should not change the color
assignments of the remaining plots.

So I think that to do this properly you'd have to mark the
plot empty (or just use the fact that npoints == 0), but carry it
along and test for this explicitly at every stage of the plotting
process. I think that would be straightforward, but it's a lot
more work than just changing one call.


-- 
Ethan A Merritt       merritt@u.washington.edu
Biomolecular Structure Center
Mailstop 357742
University of Washington, Seattle, WA 98195