def __init__(self, A_f, numLevels, theta=0.25, verb=0, graph=False):
timer = Timer('AMG setup')
self.seqA = [None]*numLevels
self.updates = [None]*numLevels
self.downdates = [None]*numLevels
self.seqA[numLevels-1] = A_f
tab1 = Tab()
tab2 = Tab()
for i in reversed(range(numLevels-1)):
Debug.msg1(verb, '-------------------------------------------------------------')
Debug.msg1(verb, tab1, 'coarsening level %d to level %d' % (i+1,i))
np.set_printoptions(threshold=np.inf)
Debug.msg4(verb, tab2, 'operator is A[%d]\n' % i, self.seqA[i+1].tolil())
C = coarsen(self.seqA[i+1], theta = theta, verb=verb)
Debug.msg2(verb, tab2, '#vertices: %d' % len(C))
if graph:
matrixGraph(self.seqA[i+1], C, name='graph-%d.gv' % i)
Debug.msg1(verb, tab1, 'making update operator: level %d to level %d' % (i+1,i))
I_up = smoothUpdate(self.seqA[i+1], C, verb)
Debug.msg1(verb, tab1, 'making downdate operator: level %d to level %d' % (i,i+1))
I_down = makeDowndate(I_up, verb)
self.updates[i] = I_up
self.downdates[i] = I_down
self.seqA[i] = self.downdates[i]*(self.seqA[i+1]*self.updates[i])
def matrixGraph(A, C, name='graph.gv', verb=0):
g = Graph(filename=name)
ip = A.indptr
allVals = A.data
allCols = A.indices
M = A.shape[0]
for i in range(M):
Debug.msg1(verb, 'i=%d' % i)
if i in C:
color = 'lightblue'
else:
color = 'lightgrey'
g.node('%d' % i, '%d' % i, color=color, style='filled')
for i in range(M):
cols = allCols[ip[i]:ip[i + 1]]
for j in cols:
if i < j:
g.edge('%d' % i, '%d' % j)
g.view()
from GoofySquare import GoofySquare1 from AMGCoarsen import coarsen from UniformRectangleMesher import UniformRectangleMesher from MPLMeshViewer import MPLMeshViewer np.set_printoptions(precision=4) mesh = UniformRectangleMesher(0.0, 1.0, 2, 0.0, 1.0, 2) beta = 0.0 load = ConstantFunc(beta*beta) (A,b) = DiscretizeDH(mesh, load, beta) np.set_printoptions(precision=4) verb=0 Debug.msg1(verb, 'A=\n', A.todense()) C = coarsen(A) I_up = smoothUpdate(A,C) I_down = makeDowndate(I_up) Debug.msg1(verb, 'Update matrix:') Debug.msg1(verb, I_up.todense()) Debug.msg1(verb, "Update row sums:") Debug.msg1(verb, I_up*np.ones(I_up.shape[1])) Debug.msg1(verb, 'Downdate matrix:')
