Files
simpeg/SimPEG/utils/ModelBuilder.py
T

271 lines
7.1 KiB
Python

import numpy as np
import scipy.ndimage as ndi
import scipy.sparse as sp
def getIndecesBlock(p0,p1,ccMesh):
"""
Creates a vector containing the block indexes in the cell centerd mesh.
Returns a tuple
The block is defined by the points
p0, describe the position of the left upper front corner, and
p1, describe the position of the right bottom back corner.
ccMesh represents the cell-centered mesh
The points p0 and p1 must live in the the same dimensional space as the mesh.
"""
# Validation: p0 and p1 live in the same dimensional space
assert len(p0) == len(p1), "Dimension mismatch. len(p0) != len(p1)"
# Validation: mesh and points live in the same dimensional space
dimMesh = np.size(ccMesh[0,:])
assert len(p0) == dimMesh, "Dimension mismatch. len(p0) != dimMesh"
if dimMesh == 1:
# Define the reference points
x1 = p0[0]
x2 = p1[0]
indX = (x1 <= ccMesh[:,0]) & (ccMesh[:,0] <= x2)
ind = np.where(indX)
elif dimMesh == 2:
# Define the reference points
x1 = p0[0]
y1 = p0[1]
x2 = p1[0]
y2 = p1[1]
indX = (x1 <= ccMesh[:,0]) & (ccMesh[:,0] <= x2)
indY = (y1 <= ccMesh[:,1]) & (ccMesh[:,1] <= y2)
ind = np.where(indX & indY)
elif dimMesh == 3:
# Define the points
x1 = p0[0]
y1 = p0[1]
z1 = p0[2]
x2 = p1[0]
y2 = p1[1]
z2 = p1[2]
indX = (x1 <= ccMesh[:,0]) & (ccMesh[:,0] <= x2)
indY = (y1 <= ccMesh[:,1]) & (ccMesh[:,1] <= y2)
indZ = (z1 <= ccMesh[:,2]) & (ccMesh[:,2] <= z2)
ind = np.where(indX & indY & indZ)
# Return a tuple
return ind
def defineBlockConductivity(p0,p1,ccMesh,condVals):
"""
Build a block with the conductivity specified by condVal. Returns an array.
condVals[0] conductivity of the block
condVals[1] conductivity of the ground
"""
sigma = np.zeros(ccMesh.shape[0]) + condVals[1]
ind = getIndecesBlock(p0,p1,ccMesh)
sigma[ind] = condVals[0]
return sigma
def defineTwoLayeredConductivity(depth,ccMesh,condVals):
"""
Define a two layered model. Depth of the first layer must be specified.
CondVals vector with the conductivity values of the layers. Eg:
Convention to number the layers::
<----------------------------|------------------------------------>
0 depth zf
1st layer 2nd layer
"""
sigma = np.zeros(ccMesh.shape[0]) + condVals[1]
dim = np.size(ccMesh[0,:])
p0 = np.zeros(dim)
p1 = np.zeros(dim)
# Identify 1st cell centered reference point
p0[0] = ccMesh[0,0]
if dim>1: p0[1] = ccMesh[0,1]
if dim>2: p0[2] = ccMesh[0,2]
# Identify the last cell-centered reference point
p1[0] = ccMesh[-1,0]
if dim>1: p1[1] = ccMesh[-1,1]
if dim>2: p1[2] = ccMesh[-1,2]
# The depth is always defined on the last one.
p1[len(p1)-1] -= depth
ind = getIndecesBlock(p0,p1,ccMesh)
sigma[ind] = condVals[0];
return sigma
def scalarConductivity(ccMesh,pFunction):
"""
Define the distribution conductivity in the mesh according to the
analytical expression given in pFunction
"""
dim = np.size(ccMesh[0,:])
CC = [ccMesh[:,0]]
if dim>1: CC.append(ccMesh[:,1])
if dim>2: CC.append(ccMesh[:,2])
sigma = pFunction(*CC)
return sigma
def randomModel(shape, seed=None, anisotropy=None, its=100, bounds=[0,1]):
"""
Create a random model by convolving a kernal with a
uniformly distributed model.
:param int,tuple shape: shape of the model.
:param int seed: pick which model to produce, prints the seed if you don't choose.
:param numpy.ndarray,list anisotropy: this is the (3 x n) blurring kernal that is used.
:param int its: number of smoothing iterations
:param list bounds: bounds on the model, len(list) == 2
:rtype: numpy.ndarray
:return: M, the model
.. plot::
import matplotlib.pyplot as plt
import SimPEG.utils.ModelBuilder as MB
plt.colorbar(plt.imshow(MB.randomModel((50,50),bounds=[-4,0])))
plt.title('A very cool, yet completely random model.')
plt.show()
"""
if seed is None:
seed = np.random.randint(1e3)
print 'Using a seed of: ', seed
if type(shape) in [int, long, float]:
shape = (shape,) # make it a tuple for consistency
np.random.seed(seed)
mr = np.random.rand(*shape)
if anisotropy is None:
if len(shape) is 1:
smth = np.array([1,10.,1],dtype=float)
elif len(shape) is 2:
smth = np.array([[1,2,1],[7,10,7],[1,2,1]],dtype=float)
elif len(shape) is 3:
kernal = np.array([1,4,1], dtype=float).reshape((1,3))
smth = np.array(sp.kron(sp.kron(kernal,kernal.T).todense()[:],kernal).todense()).reshape((3,3,3))
else:
assert len(anisotropy.shape) is len(shape), 'Anisotropy must be the same shape.'
smth = np.array(anisotropy,dtype=float)
smth = smth/smth.sum() # normalize
mi = mr
for i in range(its):
mi = ndi.convolve(mi, smth)
# scale the model to live between the bounds.
mi = (mi - mi.min())/(mi.max()-mi.min()) # scaled between 0 and 1
mi = mi*(bounds[1]-bounds[0])+bounds[0]
return mi
if __name__ == '__main__':
from SimPEG.mesh import TensorMesh
from matplotlib import pyplot as plt
# Define the mesh
testDim = 2
h1 = 0.3*np.ones(7)
h1[0] = 0.5
h1[-1] = 0.6
h2 = .5 * np.ones(4)
h3 = .4 * np.ones(6)
x0 = np.zeros(3)
if testDim == 1:
h = [h1]
x0 = x0[0]
elif testDim == 2:
h = [h1, h2]
x0 = x0[0:2]
else:
h = [h1, h2, h3]
M = TensorMesh(h, x0)
ccMesh = M.gridCC
# ------------------- Test conductivities! --------------------------
print('Testing 1 block conductivity')
p0 = np.array([0.5,0.5,0.5])[:testDim]
p1 = np.array([1.0,1.0,1.0])[:testDim]
condVals = np.array([100,1e-6])
sigma = defineBlockConductivity(p0,p1,ccMesh,condVals)
# Plot sigma model
print sigma.shape
M.plotImage(sigma)
print 'Done with block! :)'
plt.show()
# -----------------------------------------
print('Testing the two layered model')
condVals = np.array([100,1e-5]);
depth = 1.0;
sigma = defineTwoLayeredConductivity(depth,ccMesh,condVals)
M.plotImage(sigma)
print sigma
print 'layer model!'
plt.show()
# -----------------------------------------
print('Testing scalar conductivity')
if testDim == 1:
pFunction = lambda x: np.exp(x)
elif testDim == 2:
pFunction = lambda x,y: np.exp(x+y)
elif testDim == 3:
pFunction = lambda x,y,z: np.exp(x+y+z)
sigma = scalarConductivity(ccMesh,pFunction)
# Plot sigma model
M.plotImage(sigma)
print sigma
print 'Scalar conductivity defined!'
plt.show()
# -----------------------------------------