Source code for mpas_tools.mesh.creation.mpas_to_triangle

from __future__ import absolute_import, division, print_function, \

import sys
from netCDF4 import Dataset as NetCDFFile
from optparse import OptionParser

[docs]def mpas_to_triangle(mpasfile, trifile): """ Script to convert from MPAS netCDF format to the Triangle format: Parameters ---------- mpasfile : str The path to an MPAS mesh in NetCDF format trifile : str The prefix for the Triangle output files. Files with extensions ``.node`` and ``.ele`` will be produced. Only works for planar meshes. """ fin = NetCDFFile(mpasfile, 'r') if fin.on_a_sphere == "YES": sys.abort("ERROR: This script only works for planar meshes!") if len(fin.dimensions['vertexDegree']) != 3: sys.abort("ERROR: This script only works for vertexDegree of 3!") nCells = len(fin.dimensions['nCells']) nVertices = len(fin.dimensions['nVertices']) xCell = fin.variables['xCell'][:] yCell = fin.variables['yCell'][:] ConC = fin.variables['cellsOnCell'][:] nConC = fin.variables['nEdgesOnCell'][:] ConV = fin.variables['cellsOnVertex'][:] # create node file fnode = open(trifile + ".node", 'w') # write node file header: First line: <# of vertices> <dimension (must # be 2)> <# of attributes> <# of boundary markers (0 or 1)> fnode.write("{:d} 2 0 1\n".format(nCells)) # Remaining lines: <vertex #> <x> <y> [attributes] [boundary marker] for i in range(nCells): if ConC[i, 0:nConC[i]].min() == 0: isBdy = 1 else: isBdy = 0 fnode.write( "{:d} {:f} {:f} {:d}\n".format( i + 1, xCell[i], yCell[i], isBdy)) fnode.write("# Generated from MPAS file: {}\n".format(mpasfile)) fnode.close() # create ele file fele = open(trifile + ".ele", "w") # calculate number of non-degenerate triangles numtri = 0 for i in range(nVertices): if ConV[i, :].min() > 0: numtri += 1 # write ele file header: First line: <# of triangles> <nodes per # triangle> <# of attributes> fele.write("{:d} 3 0\n".format(numtri)) # Remaining lines: <triangle #> <node> <node> <node> ... [attributes] cnt = 0 for i in range(nVertices): # write non-generate triangles only if ConV[i, :].min() > 0: cnt += 1 fele.write("{:d} {:d} {:d} {:d}\n".format( cnt, ConV[i, 0], ConV[i, 1], ConV[i, 2])) fele.write("# Generated from MPAS file: {}\n".format(mpasfile)) fele.close() fin.close() print("Conversion complete.")
def main(): parser = OptionParser() parser.add_option( "-m", "--mpas", dest="mpasfile", help="input MPAS netCDF file.", metavar="FILE") parser.add_option( "-t", "--triangle", dest="trifile", help="output file name template to be in triangle format (FILE.1.node," " FILE.1.ele).", metavar="FILE") options, args = parser.parse_args() if not options.mpasfile: parser.error("An input MPAS file is required.") if not options.trifile: parser.error("A output Triangle format file name is required.") mpas_to_triangle(mpasfile=options.mpasfile, trifile=options.trifile)