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])
