import numpy as np
import matplotlib.pyplot as plt
%matplotlib inline
from scipy.interpolate import RegularGridInterpolator
RegularGridInterpolator from scipy.interpolateDo a 3D example, that is, we have some data $f_i = z_i(x_i, y_i, z_i)$
#-------- define grids in x, y, z
x = np.linspace(0,1,101)
y = np.linspace(0,1,101)
z = np.linspace(0,1,101)
#-------- define the function on the grid
X,Y,Z = np.meshgrid(x,y,z) # just used for conveninece
f = np.sin(9*X)*np.sin(9*Y)*Z
#-------- define interpolant and interpolate to "wanted" point xw, yw, zw
finterp = RegularGridInterpolator( (x,y,z), f )
xw = yw = zw = 0.155
f_w = finterp( (xw, yw, zw) )
f_w
array(0.1499549)