# Examples from pyvista.ExplicitStructuredGrid
# ============================================

import numpy as np
import pyvista as pv

# grid size: ni*nj*nk cells; si, sj, sk steps
ni, nj, nk = 4, 5, 6
si, sj, sk = 20, 10, 1

# create raw coordinate grid
grid_ijk = np.mgrid[
    : (ni + 1) * si : si,
    : (nj + 1) * sj : sj,
    : (nk + 1) * sk : sk,
]

# repeat array along each Cartesian axis for connectivity
for axis in range(1, 4):
    grid_ijk = grid_ijk.repeat(2, axis=axis)

# slice off unnecessarily doubled edge coordinates
grid_ijk = grid_ijk[:, 1:-1, 1:-1, 1:-1]

# reorder and reshape to VTK order
corners = grid_ijk.transpose().reshape(-1, 3)

dims = np.array([ni, nj, nk]) + 1
grid = pv.ExplicitStructuredGrid(dims, corners)
grid = grid.compute_connectivity()
grid.plot(show_edges=True)

# ----------------------------------------------------------------------
# Generated by sphinx-examples-as-code https://github.com/pyvista/sphinx-examples-as-code