Interpolation from a triangular basis to a rectangular grid

[martinkhouri102023]

I am new to skfem and I would like to interpolate the FE results stored in a E vector to a rectangular meshgrid I have set. I've tried to use basis.interpolator :

import skfem
import numpy as np
import matplotlib.pyplot as plt

'''Interpolation tests'''
mode = modes[0][0]
E = modes[0][0].E       # The solution I want to interpolate (E.shape : (8303,))
basis = mode.basis      
mesh = basis.mesh       # mesh.p.shape : (2, 2091)

# Get the simulation domain bounds from the mesh
x_min, x_max = mesh.p[0,:].min(), mesh.p[0,:].max()     # x_min, x_max = (-5.8,5.8)
y_min, y_max = mesh.p[1,:].min(), mesh.p[1,:].max()     # y_min, y_max = (-6.0, 9.0)

# Create a regular rectangular grid
n_pts = 200  # number of points along each dimension
x = np.linspace(x_min, x_max, n_pts)
y = np.linspace(y_min, y_max, n_pts)
X, Y = np.meshgrid(x, y)
grid_points = np.vstack([X.ravel(), Y.ravel()])

# Trial to evaluate the field from the mode on the rectangular grid.
interp_func = basis.interpolator(E)
Z = interp_func(grid_points).reshape(X.shape)

# Plot the real part of the field on the rectangular grid
plt.figure(figsize=(8,6))
plt.pcolormesh(X, Y, np.real(Z), shading='auto')
plt.colorbar(label="Real(E)")
plt.xlabel("x")
plt.ylabel("y")
plt.title("Mode Field Interpolated on a Rectangular Grid")
plt.show()

Unfortunately, that returns an error :

ValueError: row, column, and data array must all be the same length

This sounds like a very basic question, I've made searches for solutions but I don't understand why my code doesn't work. Does anyone have a solution?
Thanks!