Files
simpeg/SimPEG/utils/interputils.py
T
2013-11-04 18:17:01 -08:00

128 lines
3.4 KiB
Python

import numpy as np
import scipy.sparse as sp
from sputils import spzeros
from matutils import mkvc, sub2ind
def _interp_point_1D(x, xr_i):
im = np.argmin(abs(x-xr_i))
if xr_i - x[im] >= 0: # Point on the left
ind_x1 = im
ind_x2 = im+1
elif xr_i - x[im] < 0: # Point on the right
ind_x1 = im-1
ind_x2 = im
dx1 = xr_i - x[ind_x1]
dx2 = x[ind_x2] - xr_i
return ind_x1, ind_x2, dx1, dx2
def interpmat(locs, x, y=None, z=None):
""" Local interpolation computed for each receiver point in turn """
if y is None and z is None:
return interpmat1D(locs, x)
elif z is None:
return interpmat2D(locs, x, y)
else:
return interpmat3D(locs, x, y, z)
def interpmat1D(locs, x):
nx = x.size
locs = mkvc(locs)
npts = locs.shape[0]
Q = sp.lil_matrix((npts, nx))
for i in range(npts):
ind_x1, ind_x2, dx1, dx2 = _interp_point_1D(x, locs[i])
dv = (x[ind_x2] - x[ind_x1])
Dx = x[ind_x2] - x[ind_x1]
# Get the row in the matrix
inds = [ind_x1, ind_x2]
vals = [(1-dx1/Dx),(1-dx2/Dx)]
Q[i, inds] = vals
return Q.tocsr()
def interpmat2D(locs, x, y):
nx = x.size
ny = y.size
npts = locs.shape[0]
Q = sp.lil_matrix((npts, nx*ny))
for i in range(npts):
ind_x1, ind_x2, dx1, dx2 = _interp_point_1D(x, locs[i, 0])
ind_y1, ind_y2, dy1, dy2 = _interp_point_1D(y, locs[i, 1])
dv = (x[ind_x2] - x[ind_x1]) * (y[ind_y2] - y[ind_y1])
Dx = x[ind_x2] - x[ind_x1]
Dy = y[ind_y2] - y[ind_y1]
# Get the row in the matrix
inds = sub2ind((nx,ny),[
( ind_x1, ind_y2),
( ind_x1, ind_y1),
( ind_x2, ind_y1),
( ind_x2, ind_y2)])
vals = [(1-dx1/Dx)*(1-dy2/Dy),
(1-dx1/Dx)*(1-dy1/Dy),
(1-dx2/Dx)*(1-dy1/Dy),
(1-dx2/Dx)*(1-dy2/Dy)]
Q[i, mkvc(inds)] = vals
return Q.tocsr()
def interpmat3D(locs, x, y, z):
nx = x.size
ny = y.size
nz = z.size
npts = locs.shape[0]
Q = sp.lil_matrix((npts, nx*ny*nz))
for i in range(npts):
ind_x1, ind_x2, dx1, dx2 = _interp_point_1D(x, locs[i, 0])
ind_y1, ind_y2, dy1, dy2 = _interp_point_1D(y, locs[i, 1])
ind_z1, ind_z2, dz1, dz2 = _interp_point_1D(z, locs[i, 2])
dv = (x[ind_x2] - x[ind_x1]) * (y[ind_y2] - y[ind_y1]) *(z[ind_z2] - z[ind_z1])
Dx = x[ind_x2] - x[ind_x1]
Dy = y[ind_y2] - y[ind_y1]
Dz = z[ind_z2] - z[ind_z1]
# Get the row in the matrix
inds = sub2ind((nx,ny,nz),[
( ind_x1, ind_y2, ind_z1),
( ind_x1, ind_y1, ind_z1),
( ind_x2, ind_y1, ind_z1),
( ind_x2, ind_y2, ind_z1),
( ind_x1, ind_y1, ind_z2),
( ind_x1, ind_y2, ind_z2),
( ind_x2, ind_y1, ind_z2),
( ind_x2, ind_y2, ind_z2)])
vals = [(1-dx1/Dx)*(1-dy2/Dy)*(1-dz1/Dz),
(1-dx1/Dx)*(1-dy1/Dy)*(1-dz1/Dz),
(1-dx2/Dx)*(1-dy1/Dy)*(1-dz1/Dz),
(1-dx2/Dx)*(1-dy2/Dy)*(1-dz1/Dz),
(1-dx1/Dx)*(1-dy1/Dy)*(1-dz2/Dz),
(1-dx1/Dx)*(1-dy2/Dy)*(1-dz2/Dz),
(1-dx2/Dx)*(1-dy1/Dy)*(1-dz2/Dz),
(1-dx2/Dx)*(1-dy2/Dy)*(1-dz2/Dz)]
Q[i, mkvc(inds)] = vals
return Q.tocsr()