matplotlib pcolormesh plot from x,y,z data

Question

I have data in a textfile in tableform with three columns. I use np.genfromtxt to read all the columns into matplotlib as x, y, z.

I want to create a color meshplot

Answer 1

It seems you are plotting X and Y as 2D arrays while Z is still a 1D array. Try something like:

Znew=np.reshape(z,(len(xmesh[:,0]),len(xmesh[0,:])))
diagram1.pcolormesh(xmesh,ymesh,Znew) 

Update: Tou have a X/Y grid of size 4x4:

x = np.genfromtxt('mesh.txt', dtype=float, delimiter=' ', usecols = (0))
y = np.genfromtxt('mesh.txt', dtype=float, delimiter=' ', usecols = (1))
z = np.genfromtxt('mesh.txt', dtype=float, delimiter=' ', usecols = (2))

Reshape the arrays as suggestet by @Gustav Larsson and myself like this:

Xnew=np.reshape(x,(4,4)) 
Xnew=np.reshape(y,(4,4))
Znew=np.reshape(z,(4,4))

Which gives you three 4x4 arrays to plot using pcolormesh:

diagram1.pcolormesh(Xnew,Ynew,Znew)