# -*- coding: utf-8 -*-
"""
_______ _______ ___ __ __ _______ _______
| || || | | | | || || |
| ___|| ___|| | | | | || _ || ___|
| |___ | |___ | | | |_| || |_| || |___
| ___|| ___|| |___ | || ___|| ___|
| | | |___ | || || | | |___
|___| |_______||_______||_______||___| |_______|
This file is part of felupe.
Felupe is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Felupe is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Felupe. If not, see <http://www.gnu.org/licenses/>.
"""
import numpy as np
from copy import deepcopy
[docs]class Mesh:
"""A mesh with points, cells and optional a specified cell type.
Parameters
----------
points : ndarray
Point coordinates.
cells : ndarray
Point-connectivity of cells.
cell_type : str or None, optional
An optional string in VTK-convention that specifies the cell type (default is None). Necessary when a mesh is saved to a file.
Attributes
----------
points : ndarray
Point coordinates.
cells : ndarray
Point-connectivity of cells.
cell_type : str or None
A string in VTK-convention that specifies the cell type.
npoints : int
Amount of points.
dim : int
Dimension of mesh point coordinates.
ndof : int
Amount of degrees of freedom.
ncells : int
Amount of cells.
points_with_cells : array
Array with points connected to cells.
points_without_cells : array
Array with points not connected to cells.
cells_per_point : array
Array which counts connected cells per point. Used for averging results.
"""
def __init__(self, points, cells, cell_type=None):
self.points = np.array(points)
self.cells = np.array(cells)
self.cell_type = cell_type
self.update(self.cells)
[docs] def update(self, cells):
"Update the cell and dimension attributes with a given cell array."
self.cells = cells
# obtain dimensions
self.npoints, self.dim = self.points.shape
self.ndof = self.points.size
self.ncells = self.cells.shape[0]
# get number of cells per point
points_in_cell, self.cells_per_point = np.unique(cells, return_counts=True)
# check if there are points without cells
if self.npoints != len(self.cells_per_point):
self.point_has_cell = np.isin(np.arange(self.npoints), points_in_cell)
# update "cells_per_point" ... cells per point
cells_per_point = -np.ones(self.npoints, dtype=int)
cells_per_point[points_in_cell] = self.cells_per_point
self.cells_per_point = cells_per_point
self.points_without_cells = np.arange(self.npoints)[~self.point_has_cell]
self.points_with_cells = np.arange(self.npoints)[self.point_has_cell]
else:
self.points_without_cells = np.array([], dtype=int)
self.points_with_cells = np.arange(self.npoints)
[docs] def disconnect(self):
"Return a new instance of a Mesh with disconnected cells."
points = self.points[self.cells].reshape(-1, self.dim)
cells = np.arange(self.cells.size).reshape(*self.cells.shape)
return Mesh(points, cells, cell_type=self.cell_type)
[docs] def as_meshio(self, **kwargs):
"""Export the mesh as ``meshio.Mesh``.
Parameters
----------
filename : str, optional
The filename of the mesh (default is ``mesh.vtk``).
"""
import meshio
cells = {self.cell_type: self.cells}
return meshio.Mesh(self.points, cells, **kwargs)
[docs] def save(self, filename="mesh.vtk", **kwargs):
"""Export the mesh as VTK file. For XDMF-export please ensure to have
``h5py`` (as an optional dependancy of ``meshio``) installed.
Parameters
----------
filename : str, optional
The filename of the mesh (default is ``mesh.vtk``).
"""
self.as_meshio(**kwargs).write(filename)
[docs] def copy(self):
"""Return a deepcopy of the mesh.
Returns
-------
Mesh
A deepcopy of the mesh.
"""
return deepcopy(self)