#3957 plot2d(0=0,...) -- true everywhere

[Stavros Macrakis]

plot2d(0=0,[x,0,1],[y,0,1])and plot2d(floor(x)=0,[x,0,1],[y,0,1]) give the "nothing to plot" error, even though they is true everywhere in the plot area -- if it has noticed that, maybe the error could be clearer.

Or alternatively it could just show the whole area of the graph with cross-hatching. After all, as soon it is not true somewhere , it shows a plot, e.g., plot2d(floor(x)=0,[x,0,1.1],[y,0,1]).

[Jaime E. Villate]

That's a nice challenge for someone to fix, perhaps a student? I have a long list of other things to fix that I consider more important :)