Files
simpeg/SimPEG/Utils/meshutils.py
T
Gudni UBC-Talva e0f2d50a1d Fixed read and write UBC TensorMesh and model such that indexing is
SimPEG: ref point at bottom-south-west corner, running x-y-z
UBC: ref point at top-south-west corner, running z-x-y
2014-05-06 14:15:41 -07:00

208 lines
6.7 KiB
Python

import numpy as np
from scipy import sparse as sp
from matutils import mkvc, ndgrid, sub2ind, sdiag
from codeutils import asArray_N_x_Dim
from codeutils import isScalar
def exampleLrmGrid(nC, exType):
assert type(nC) == list, "nC must be a list containing the number of nodes"
assert len(nC) == 2 or len(nC) == 3, "nC must either two or three dimensions"
exType = exType.lower()
possibleTypes = ['rect', 'rotate']
assert exType in possibleTypes, "Not a possible example type."
if exType == 'rect':
return list(ndgrid([np.cumsum(np.r_[0, np.ones(nx)/nx]) for nx in nC], vector=False))
elif exType == 'rotate':
if len(nC) == 2:
X, Y = ndgrid([np.cumsum(np.r_[0, np.ones(nx)/nx]) for nx in nC], vector=False)
amt = 0.5-np.sqrt((X - 0.5)**2 + (Y - 0.5)**2)
amt[amt < 0] = 0
return [X + (-(Y - 0.5))*amt, Y + (+(X - 0.5))*amt]
elif len(nC) == 3:
X, Y, Z = ndgrid([np.cumsum(np.r_[0, np.ones(nx)/nx]) for nx in nC], vector=False)
amt = 0.5-np.sqrt((X - 0.5)**2 + (Y - 0.5)**2 + (Z - 0.5)**2)
amt[amt < 0] = 0
return [X + (-(Y - 0.5))*amt, Y + (-(Z - 0.5))*amt, Z + (-(X - 0.5))*amt]
def meshTensor(value):
"""
**meshTensor** takes a list of numbers and tuples that have the form::
mT = [ float, (cellSize, numCell), (cellSize, numCell, factor) ]
For example, a time domain mesh code needs
many time steps at one time::
[(1e-5, 30), (1e-4, 30), 1e-3]
Means take 30 steps at 1e-5 and then 30 more at 1e-4,
and then one step of 1e-3.
Tensor meshes can also be created by increase factors::
[(10.0, 5, -1.3), (10.0, 50), (10.0, 5, 1.3)]
When there is a third number in the tuple, it
refers to the increase factor, if this number
is negative this section of the tensor is flipped right-to-left.
.. plot::
from SimPEG import Mesh
tx = [(10.0,10,-1.3),(10.0,40),(10.0,10,1.3)]
ty = [(10.0,10,-1.3),(10.0,40)]
M = Mesh.TensorMesh([tx, ty])
M.plotGrid(showIt=True)
"""
if type(value) is not list:
raise Exception('meshTensor must be a list of scalars and tuples.')
proposed = []
for v in value:
if isScalar(v):
proposed += [float(v)]
elif type(v) is tuple and len(v) == 2:
proposed += [float(v[0])]*int(v[1])
elif type(v) is tuple and len(v) == 3:
start = float(v[0])
num = int(v[1])
factor = float(v[2])
pad = ((np.ones(num)*np.abs(factor))**(np.arange(num)+1))*start
if factor < 0: pad = pad[::-1]
proposed += pad.tolist()
else:
raise Exception('meshTensor must contain only scalars and len(2) or len(3) tuples.')
return np.array(proposed)
def closestPoints(mesh, pts, gridLoc='CC'):
"""
Move a list of points to the closest points on a grid.
:param simpeg.Mesh.BaseMesh mesh: The mesh
:param numpy.ndarray pts: Points to move
:param string gridLoc: ['CC', 'N', 'Fx', 'Fy', 'Fz', 'Ex', 'Ex', 'Ey', 'Ez']
:rtype: numpy.ndarray
:return: nodeInds
"""
pts = asArray_N_x_Dim(pts, mesh.dim)
grid = getattr(mesh, 'grid' + gridLoc)
nodeInds = np.empty(pts.shape[0], dtype=int)
for i, pt in enumerate(pts):
nodeInds[i] = ((np.tile(pt, (grid.shape[0],1)) - grid)**2).sum(axis=1).argmin()
return nodeInds
def readUBCTensorMesh(fileName):
"""
Read UBC GIF 3DTensor mesh and generate 3D Tensor mesh in simpegTD
Input:
:param fileName, path to the UBC GIF mesh file
Output:
:param SimPEG TensorMesh object
:return
"""
# Interal function to read cell size lines for the UBC mesh files.
def readCellLine(line):
for seg in line.split():
if '*' in seg:
st = seg
sp = seg.split('*')
re = np.array(sp[0],dtype=int)*(' ' + sp[1])
line = line.replace(st,re.strip())
return np.array(line.split(),dtype=float)
# Read the file as line strings, remove lines with comment = !
msh = np.genfromtxt(fileName,delimiter='\n',dtype=np.str,comments='!')
# Fist line is the size of the model
sizeM = np.array(msh[0].split(),dtype=float)
# Second line is the South-West-Top corner coordinates.
x0 = np.array(msh[1].split(),dtype=float)
# Read the cell sizes
h1 = readCellLine(msh[2])
h2 = readCellLine(msh[3])
h3temp = readCellLine(msh[4])
h3 = h3temp[::-1] # Invert the indexing of the vector to start from the bottom.
# Adjust the reference point to the bottom south west corner
x0[2] = x0[2] - np.sum(h3)
# Make the mesh
from SimPEG import Mesh
tensMsh = Mesh.TensorMesh([h1,h2,h3],x0)
return tensMsh
def readUBCTensorModel(fileName, mesh):
"""
ReadUBC 3DTensor mesh model and generate 3D Tensor mesh model in simpegTD
"""
f = open(fileName, 'r')
model = np.array(map(float, f.readlines()))
f.close()
model = np.reshape(model, (mesh.nCz, mesh.nCx, mesh.nCy), order = 'F')
model = model[::-1,:,:]
model = np.transpose(model, (1, 2, 0))
model = mkvc(model)
return model
def writeUBCTensorMesh(mesh, fileName):
"""
Writes a SimPEG TensorMesh to a UBC-GIF format mesh file.
:param simpeg.Mesh.TensorMesh mesh: The mesh
:param str fileName: File to write to
"""
assert mesh.dim == 3
s = ''
s += '%i %i %i\n' %tuple(mesh.vnC)
origin = mesh.x0
origin.dtype = float
origin[2] = origin[2]+mesh.hz.sum()
s += '%.2f %.2f %.2f\n' %tuple(origin)
s += ('%.2f '*mesh.nCx+'\n')%tuple(mesh.hx)
s += ('%.2f '*mesh.nCy+'\n')%tuple(mesh.hy)
s += ('%.2f '*mesh.nCz+'\n')%tuple(mesh.hz[::-1])
f = open(fileName, 'w')
f.write(s)
f.close()
def writeUBCTensorModel(mesh, model, fileName):
"""
Writes a model associated with a SimPEG TensorMesh
to a UBC-GIF format model file.
:param simpeg.Mesh.TensorMesh mesh: The mesh
:param numpy.ndarray model: The model
:param str fileName: File to write to
"""
# Reshape model to a matrix
modelMat = mesh.r(model,'CC','CC','M')
# Transpose the axes
modelMatT = modelMat.transpose((2,0,1))
# Flip z to positive down
modelMatTR = mkvc(modelMatT[::-1,:,:])
np.savetxt(fileName, modelMatTR.ravel())
if __name__ == '__main__':
from SimPEG import Mesh
import matplotlib.pyplot as plt
tx = [(10.0,10,-1.3),(10.0,40),(10.0,10,1.3)]
ty = [(10.0,10,-1.3),(10.0,40)]
M = Mesh.TensorMesh([tx, ty])
M.plotGrid()
plt.gca().axis('tight')
plt.show()