from __future__ import absolute_import, division, print_function, \
unicode_literals
import numpy as np
from netCDF4 import Dataset as NetCDFFile
from mpas_tools.mesh.creation.util import circumcenter
import argparse
[docs]def triangle_to_netcdf(node, ele, output_name):
"""
Converts mesh data defined in triangle format to NetCDF
Parameters
----------
node : str
A node file name
ele : str
An element file name
output_name: str
The name of the output file
"""
# Authors: Phillip J. Wolfram, Matthew Hoffman and Xylar Asay-Davis
on_sphere = False
grid = NetCDFFile(output_name, 'w', format='NETCDF3_CLASSIC')
# Get dimensions
# Get nCells
cell_info = open(node, 'r')
nCells = -1 # There is one header line
for block in iter(lambda: cell_info.readline(), ""):
if block.startswith("#"):
continue # skip comment lines
nCells = nCells + 1
cell_info.close()
# Get vertexDegree and nVertices
cov_info = open(ele, 'r')
vertexDegree = 3 # always triangles with Triangle!
nVertices = -1 # There is one header line
for block in iter(lambda: cov_info.readline(), ""):
if block.startswith("#"):
continue # skip comment lines
nVertices = nVertices + 1
cov_info.close()
if vertexDegree != 3:
ValueError("This script can only compute vertices with triangular "
"dual meshes currently.")
grid.createDimension('nCells', nCells)
grid.createDimension('nVertices', nVertices)
grid.createDimension('vertexDegree', vertexDegree)
# Create cell variables and sphere_radius
xCell_full = np.zeros((nCells,))
yCell_full = np.zeros((nCells,))
zCell_full = np.zeros((nCells,))
cell_info = open(node, 'r')
cell_info.readline() # read header
i = 0
for block in iter(lambda: cell_info.readline(), ""):
block_arr = block.split()
if block_arr[0] == "#":
continue # skip comment lines
xCell_full[i] = float(block_arr[1])
yCell_full[i] = float(block_arr[2])
zCell_full[i] = 0.0 # z-position is always 0.0 in a planar mesh
i = i + 1
cell_info.close()
grid.on_a_sphere = "NO"
grid.sphere_radius = 0.0
cellsOnVertex_full = np.zeros(
(nVertices, vertexDegree), dtype=np.int32)
cov_info = open(ele, 'r')
cov_info.readline() # read header
iVertex = 0
for block in iter(lambda: cov_info.readline(), ""):
block_arr = block.split()
if block_arr[0] == "#":
continue # skip comment lines
cellsOnVertex_full[iVertex, :] = int(-1)
# skip the first column, which is the triangle number, and then
# only get the next 3 columns
for j in np.arange(0, 3):
cellsOnVertex_full[iVertex, j] = int(block_arr[j + 1])
iVertex = iVertex + 1
cov_info.close()
# Create vertex variables
xVertex_full = np.zeros((nVertices,))
yVertex_full = np.zeros((nVertices,))
zVertex_full = np.zeros((nVertices,))
for iVertex in np.arange(0, nVertices):
cell1 = cellsOnVertex_full[iVertex, 0]
cell2 = cellsOnVertex_full[iVertex, 1]
cell3 = cellsOnVertex_full[iVertex, 2]
x1 = xCell_full[cell1 - 1]
y1 = yCell_full[cell1 - 1]
z1 = zCell_full[cell1 - 1]
x2 = xCell_full[cell2 - 1]
y2 = yCell_full[cell2 - 1]
z2 = zCell_full[cell2 - 1]
x3 = xCell_full[cell3 - 1]
y3 = yCell_full[cell3 - 1]
z3 = zCell_full[cell3 - 1]
pv = circumcenter(on_sphere, x1, y1, z1, x2, y2, z2, x3, y3, z3)
xVertex_full[iVertex] = pv.x
yVertex_full[iVertex] = pv.y
zVertex_full[iVertex] = pv.z
meshDensity_full = grid.createVariable(
'meshDensity', 'f8', ('nCells',))
meshDensity_full[0:nCells] = 1.0
var = grid.createVariable('xCell', 'f8', ('nCells',))
var[:] = xCell_full
var = grid.createVariable('yCell', 'f8', ('nCells',))
var[:] = yCell_full
var = grid.createVariable('zCell', 'f8', ('nCells',))
var[:] = zCell_full
var = grid.createVariable('xVertex', 'f8', ('nVertices',))
var[:] = xVertex_full
var = grid.createVariable('yVertex', 'f8', ('nVertices',))
var[:] = yVertex_full
var = grid.createVariable('zVertex', 'f8', ('nVertices',))
var[:] = zVertex_full
var = grid.createVariable(
'cellsOnVertex', 'i4', ('nVertices', 'vertexDegree',))
var[:] = cellsOnVertex_full
grid.sync()
grid.close()
def main():
parser = argparse.ArgumentParser(
description=__doc__,
formatter_class=argparse.RawTextHelpFormatter)
parser.add_argument(
"-n",
"--node",
dest="node",
required=True,
help="input .node file generated by Triangle.",
metavar="FILE")
parser.add_argument(
"-e",
"--ele",
dest="ele",
required=True,
help="input .ele file generated by Triangle.",
metavar="FILE")
parser.add_argument(
"-o",
"--output",
dest="output",
default="grid.nc",
help="output file name.",
metavar="FILE")
options = parser.parse_args()
triangle_to_netcdf(options.node, options.ele, options.output)