Hi John and All, On 6/1/07, Andrea Gavana wrote: > Hi John, > > On 5/31/07, John Hunter wrote: > > On 5/31/07, Andrea Gavana <[EMAIL PROTECTED]> wrote: > > > Hi All, > > > > > > I am writing an application (wxPython based) which embeds a big > > > matplotlib figure as a main panel. Basically, this app shows oil well > > > producers and gas injectors on a 2D map as dots (every dot represents > > > its surface location), and a bunch of "streamlines" (i.e., straight > > > lines or simple curves) which connect injectors and producers. > > > As the numerical simulation continues, more and more streamlines are > > > added to the plot (because of new wells or because interference > > > between wells), and actually I end up having 200 dots plus 800-1200 > > > lines. As the simulation progresses, the plots become slower and > > > slower... > > > As the lines are usually 2-points straight lines, I was thinking about > > > using Line Collections; however, every matplotlib line has a linewidth > > > value that is dependent on the calculated "interference" effect > > > between wells, which means I have to build a matplotlib line for every > > > line connecting an injector with a producer. Moreover, every injector > > > well has its own colour for the streamlines (there are 33 injector > > > wells). > > > Will Line Collections save some time in this case? If not, does anyone > > > have a suggestion on how I could try to speed-up the plotting? I am > > > not really familiar with some obscure line/axes properties, so I may > > > have overlooked something. > > > > Yes, a line collection will save you a lot of time with upwards of > > 1000 line segments. This is the use case they were designed to solve: > > a bunch of segments of differing widths and colors. One could > > optimize it for the special case of simple line segments, ie [(x1,y1), > > (x2, y2)] in which case we could use numpy arrays, but currently we > > have only the general case of a collection of arbitrary length > > segments, and since they are not necessarily the same length, we use a > > sequence of segments rather than an array, and this is slower than it > > could be. > > I managed to get things twice faster than before using Line > Collections (even though some more optimization can be done). However, > I am facing a problem with the legend: as I put all the lines in a > single collection, and I don't want all the lines to be marked in the > legend but only the ones with biggest linewidth for every injector > well, how do I get a particular line of the collection in order to > legend() that line only? I didn't find any method or attribute about > that. Maybe it is just plain impossible. > > Thank you for every hint.
I probably solved this thing, with a workaround instead of a real solution. Instead of definining a single Line Collection for all the lines, I just build a Line Collection for every injector well (from which the lines start). That means I have at most 33 Line Collections to plot instead of 800-1000 calls to axis.plot(), and I can use the legend() command. It's not optimal, but it works sufficiently fast. I still have a couple of questions: 1) I am plotting a bunch of points (which represent the well positions on a 2D map) and next to them the well names as axis.text() instances. I don't think something like a "Text Collection" exists, but is there a way to draw a bunch of texts without a loop? 2) I am currently using the pure Python implementation of the WxAgg backend, as with wxPython 2.8.4 and the pyd backend I always get the message that "wxPython2.6-unicode can not be found" or something like that. Is there any plan to adapt matplotlib to use the available wxPython installation instead of a predefined one? And, in this respect, will I get any performance improvement for the kind of plots I am doing right now? Thank you for your suggestions. Andrea. "Imagination Is The Only Weapon In The War Against Reality." http://xoomer.virgilio.it/infinity77/ ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
