Source code for pyamg.gallery.mesh

"""Generates simple meshes"""

__docformat__ = "restructuredtext en"

import numpy

__all__ = ['regular_triangle_mesh']

[docs]def regular_triangle_mesh(nx, ny): """Construct a regular triangular mesh in the unit square Parameters ---------- nx : int Number of nodes in the x-direction ny : int Number of nodes in the y-direction Returns ------- Vert : array nx*ny x 2 vertex list E2V : array Nex x 3 element list Examples -------- >>> E2V,Vert = regular_triangle_mesh(3, 2) """ nx,ny = int(nx),int(ny) if nx < 2 or ny < 2: raise ValueError('minimum mesh dimension is 2: %s' % ((nx,ny),) ) Vert1 = numpy.tile(numpy.arange(0, nx-1), ny - 1) + numpy.repeat(numpy.arange(0, nx * (ny - 1), nx), nx - 1) Vert3 = numpy.tile(numpy.arange(0, nx-1), ny - 1) + numpy.repeat(numpy.arange(0, nx * (ny - 1), nx), nx - 1) + nx Vert2 = Vert3 + 1 Vert4 = Vert1 + 1 Verttmp = numpy.meshgrid(numpy.arange(0, nx, dtype='float'), numpy.arange(0, ny, dtype='float')) Verttmp = (Verttmp[0].ravel(),Verttmp[1].ravel()) Vert = numpy.vstack(Verttmp).transpose() Vert[:,0] = (1.0 / (nx - 1)) * Vert[:,0] Vert[:,1] = (1.0 / (ny - 1)) * Vert[:,1] E2V1 = numpy.vstack((Vert1,Vert2,Vert3)).transpose() E2V2 = numpy.vstack((Vert1,Vert4,Vert2)).transpose() E2V = numpy.vstack((E2V1,E2V2)) return Vert,E2V