Files
simpeg/SimPEG/interpmat.py
T
2013-08-02 01:51:10 -07:00

94 lines
2.8 KiB
Python

from scipy import sparse as sp
import numpy as np
def interpmat(x,y,z,xr,yr,zr):
#
# This function does local linear interpolation
# computed for each receiver point in turn
#
# [Q] = linint(x,y,z,xr,yr,zr)
# Interpolation matrix
#
nx = np.size(x)
ny = np.size(y)
nz = np.size(z)
nps = np.size(xr)
#Q = spalloc(np,nx*ny*nz,8*np);
Q = sp.lil_matrix((nps,nx*ny*nz))
ind_x = np.array([0,0])
ind_y = np.array([0,0])
ind_z = np.array([0,0])
dx, dy, dz = np.zeros(2), np.zeros(2), np.zeros(2)
for i in range(0, nps):
im = np.argmin(abs(xr[i]-x))
print i,im
if xr[i] - x[im] >= 0: # Point on the left
ind_x[0] = im; ind_x[1] = im+1
else: # Point on the right
ind_x[0] = im-1; ind_x[1] = im
dx[0] = xr[i] - x[ind_x[0]]
dx[1] = x[ind_x[1]] - xr[i]
im = np.argmin(abs(yr[i] - y))
if yr[i] - y[im] >= 0: # Point on the left
ind_y[0] = im; ind_y[1] = im+1
else: # Point on the right
ind_y[0] = im-1; ind_y[1] = im
dy[0] = yr[i] - y[ind_y[0]]
dy[1] = y[ind_y[1]] - yr[i];
im = np.argmin(abs(zr[i] - z));
if zr[i] -z[im] >= 0: # Point on the left
ind_z[0] = im; ind_z[1] = im+1
else: # Point on the right
ind_z[0] = im-1; ind_z[1] = im;
dz[0] = zr[i] - z[ind_z[0]]; dz[1] = z[ind_z[1]] - zr[i]
Dx = x[ind_x[1]] - x[ind_x[0]]
Dy = y[ind_y[1]] - y[ind_y[0]]
Dz = z[ind_z[1]] - z[ind_z[0]]
#dv = Dx*Dy*Dz
# Get the row in the matrix
v = np.zeros([nx, ny,nz])
v[ ind_x[0], ind_y[0], ind_z[0]] = (1-dx[0]/Dx)*(1-dy[0]/Dy)*(1-dz[0]/Dz)
v[ ind_x[0], ind_y[1], ind_z[0]] = (1-dx[0]/Dx)*(1-dy[1]/Dy)*(1-dz[0]/Dz)
v[ ind_x[1], ind_y[0], ind_z[0]] = (1-dx[1]/Dx)*(1-dy[0]/Dy)*(1-dz[0]/Dz)
v[ ind_x[1], ind_y[1], ind_z[0]] = (1-dx[1]/Dx)*(1-dy[1]/Dy)*(1-dz[0]/Dz)
v[ ind_x[0], ind_y[0], ind_z[1]] = (1-dx[0]/Dx)*(1-dy[0]/Dy)*(1-dz[1]/Dz)
v[ ind_x[0], ind_y[1], ind_z[1]] = (1-dx[0]/Dx)*(1-dy[1]/Dy)*(1-dz[1]/Dz)
v[ ind_x[1], ind_y[0], ind_z[1]] = (1-dx[1]/Dx)*(1-dy[0]/Dy)*(1-dz[1]/Dz)
v[ ind_x[1], ind_y[1], ind_z[1]] = (1-dx[1]/Dx)*(1-dy[1]/Dy)*(1-dz[1]/Dz)
print(np.shape(v.flatten('F')))
print(np.shape(Q))
Q[i,:] = v.flatten('F')
return Q.tocsr()
if __name__ == '__main__':
x = np.array([1.1, 2.1, 3.6, 4.9])
y = np.array([1.2, 2.2, 3.3, 4.9, 5.6])
z = np.array([0.8, 1.7, 4.9, 6.5])
xr = np.array([2.5,3.2])
yr = np.array([2.4,3.6])
zr = np.array([2.5,3.9])
A = interpmat(x,y,z,xr,yr,zr)