[Matplotlib-users] plotting a contour map from CSV file

[Tim M. <tim...@gm...>]

Dear Matplotlib-Users,
I am tryring to create a contour plot over a basemap.

My main problem is creating the array for the Z values as a basis for the
plt.contour command from a CSV file where latitude, longitude and value are
stored column-wise:

lat;	lon;	value
50;	10;	6
...

The data represents a regular spaced grid with a datapoint each 0.25 degrees.

I tried various possibilities but didn't have success:

1) following simpletest.py from the basemap examples:
X, Y = meshgrid(data[:,1], data[:,0])

Z = data[:,2]

m.contourf(x,y, Z)

=> Error: Z must be a 2D array
-> How do I get Z to be a 2D array?

2) using the griddata package
Here I was nearly without orientation how to call griddata correctly.


3) Using the python bindings of ogr
Any examples on this one?

>From my above demonstrated methods the following questions arrise:
What is the preferred way to plot
	- Points stored in the above descripbed format (lat, lon, value)?
	- Interpolate a grid of data points by using different interpolation methods
like inverse distance wheighting, natural neighbor  interpolation, etc. to get a
contour map?

Thanks in advance for your help & kind regards,
Timmie