Spline Interpolation of a 2D Histogram - Python

Question

i have a 2D Histogram (x,y coordinates and a “weight”) and i need to do a spline interpolation and extract data (so not only graphical), how can i do that with python? (i attach here the histo) Thanks! LightMap X_Z

Answer 1

You can use scipy, I took the following example from here and modified it slightly:

from scipy import interpolate
import matplotlib.pyplot as plt

# define range of x values
x = np.arange(-5.01, 5.01, 0.25)
# define range of z values
z = np.arange(-5.01, 5.01, 0.25)
# create a meshgrid
xx, zz = np.meshgrid(x, z)
# these weights would be given to you in your histogram - here is an example function to generate weights
weights = np.sin(xx**2+zz**2)
# create interpolation object
f = interpolate.interp2d(x, z, weights, kind='cubic')

# generate new ranges of x and z values
xnew = np.arange(-5.01, 5.01, 1e-2)
znew = np.arange(-5.01, 5.01, 1e-2)
# interpolate 
weightsnew = f(xnew, znew)

# plot
plt.imshow(weightsnew)
plt.show()