Re: Speeding Up gnuplot Interface with Binary Data

[David Bateman]

John W. Eaton wrote:
> The follwoing commands that we are now sending to gnuplot
> unconditionally seem to be the ones causing trouble:
>
>   set tmargin 0;
>   set bmargin 0;
>   set lmargin 0;
>   set rmargin 0;
>
> These were moved in the changeset
>
>   http://hg.savannah.gnu.org/hgweb/octave/rev/f6ca8ff51818
>
> Maybe David can comment on the reason for this change.

In fact they were even there till recently. I believe Dmitri proposed 
them (but I was working on a patch that used zero margins in any case). 
I also discussed the reasoning for this in the thread on plotyy/colorbar 
last week.

What this supposed to do is that the Position property on the axes 
corresponds the the plot, without the labels, etc, and so using zero 
margins rather than automatic margins tells gnuplot that the graph size 
is exactly what you give it with "set size" and the axis labels are 
outside of that. This allows easy plot alignment in subplots and plotyy, 
and is needed to get consistent behavior with colorbars that are images 
as my recent changes makes them (ie a plot with a colorbar keep the same 
OuterPosition as a plot without one but modifies the Position property).

However, it also now appears that gnuplot assumes that the bounding box 
calculation with zero margins is based on the value give with "set 
szie"... Grrrrrrrr, then I'm not sure how to reconcile the need to set 
the plot size  based on the axes "position" variable and the 
bounding-box in the postscript plots by the OuterPosition property..

D.

--
David Bateman                                address@hidden
35 rue Gambetta                              +33 1 46 04 02 18 (Home)
92100 Boulogne-Billancourt FRANCE            +33 6 72 01 06 33 (Mob)