On 7/13/10 4:46 AM, David Sanders wrote:
Hi,I need to superimpose several region_plot's. These have regions colored in different colors which may or may not overlap. However, if I do something like var('p q') plot1 = region_plot([p+q<1, p+q>-1], (p,-2,2), (q,-2,2), incol='red') plot2 = region_plot([p-q<1, p-q>-1], (p,-2,2), (q,-2,2), incol='blue') show(plot1+plot2) then I see at most the outline of the first plot. It seems that the second plot covers up the first plot, since the default value of outcol is 'white'. Is there any way to make these plots transparent (i.e. with an alpha value less than 1), or at least not opaque? I tried putting the option outcol=None but this is not accepted. This would seem to me to be the first way of solving the issue. I had a look at the code for region_plot, which I at least understand the idea of. It uses matplotlib for the graphics, so perhaps the question of transparency is a matplotlib question. Nonetheless, I believe that matplotlib does have this capability, so this should be possible...!
It seems that adding transparency is a natural way to do this. I've posted a rough patch to do this up at http://trac.sagemath.org/sage_trac/ticket/9491
I've also attached a figure resulting from:
var('p q')
plot1 = region_plot([p+q<1, p+q>-1], (p,-2,2), (q,-2,2), incol='red',
opacity=0.5)
plot2 = region_plot([p-q<1, p-q>-1], (p,-2,2), (q,-2,2), incol='blue',
opacity=0.5)
show(plot1+plot2)Sorry I don't have right now to finish the patch and ask for review; I'm rushing out the door.
Thanks, Jason -- To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
<<attachment: regionplot.png>>
