Generate Density Plot (of big data set) to Overlay in Google Maps
<p>I am computing geographical densities by using MySQL polynomials to create a grid over a specific location in the world.  I use geospatial indices on the grid in order to improve speed when I run the MySQL st_contains command.  It all works great but it very slow since I use a resolution of 1/1000 of a degree.  Below is a plot using Google Maps API polyline to draw the grids and the coloring the grids based on the count found using st_contains.  Since I need to do the entire world, I need to switch to less resolution for my grid.    </p>

<p>I have tried the following Python plotting routines:  pcolormesh, imshow, heatmap, scatter, and contourf.   I have looked at also interpolating using Pythons griddata. I have not found something equivalent to plotting the polylines in Google Maps.  Any recommendations?</p>

<p><a href="http://i.stack.imgur.com/gcW8O.jpg" rel="nofollow">Google Maps API results</a>
<a href="http://i.stack.imgur.com/wOUbq.png" rel="nofollow">Python Contourf</a></p>