faster way of plotting large number of markers in different colors

[GoogleCodeExporter]

What new or enhanced feature are you proposing?
plotting markers in different colors(at least 3) in large quantities (about 
50000 or more) as faster as possible(less than about 3 secs).

problem encountered:

i have already added above feature in my modified map with markers in 3 
different colors. the expected number of markers to be plotted is maximum 
50000. the problem is, it is too slow and the map get stuck until all 50000 
makers are loaded in 'for' loop. markers are read from a mysql table using a 
curser objet, instead of the marker file.

but when i use a separate method(event for a "show markers" button), then the 
map does not get stuck while markers are being plotted. any solution for faster 
way of plotting markers without getting stuck. please help!

Original issue reported on code.google.com by dilshanl...@gmail.com on 30 Mar 2013 at 6:10

[GoogleCodeExporter]

MySQL is not going to make any difference in the speed of the drawing, the 
marker file is read only once when the app loads.

To make it faster you can try using threads

Original comment by heldersepu on 22 Jul 2013 at 1:17

• Changed state: Done

[GoogleCodeExporter]

i have the same problem. what is the most efficient way of using threads? 
1. call draw overlay method in a separate thread
2. create separate threads for each marker for all 50000 markers, in 
widdrawingarea.py  

Original comment by thilinai...@gmail.com on 22 Jul 2013 at 2:09

[GoogleCodeExporter]

Is hard to tell!
Test all theories, see which one works best for you

Original comment by heldersepu on 22 Jul 2013 at 2:23

[GoogleCodeExporter]

I'd stay away from second solution at least, you'll run into problems with 
process limits very, very fast.

Original comment by kipenros...@gmail.com on 22 Jul 2013 at 2:57

[GoogleCodeExporter]

what about multiprocessing? can it be used in gmapcatcher? it seems not.

Original comment by thilinai...@gmail.com on 22 Jul 2013 at 3:01

[GoogleCodeExporter]

first solution cannot reach expected speed according to my implementation (i 
need all 50000 to be plotted at least withing 1 min). and it gets stuck at the 
middle after plotting about 1000 or 2000 markers, cannot find the reason for 
it..

Original comment by thilinai...@gmail.com on 22 Jul 2013 at 3:08