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import numpy as Numeric
import math
from pysparse import spmatrix
from pysparse import itsolvers
from pysparse import precon
from pysparse import jdsym
import time
def poisson2d_sym_blk(n):
L = spmatrix.ll_mat_sym(n*n)
I = spmatrix.ll_mat_sym(n)
P = spmatrix.ll_mat_sym(n)
for i in range(n):
I[i,i] = -1
for i in range(n):
P[i,i] = 4
if i > 0: P[i,i-1] = -1
for i in range(0, n*n, n):
L[i:i+n,i:i+n] = P
if i > 0: L[i:i+n,i-n:i] = I
return L
n = 200
t1 = time.clock()
L = poisson2d_sym_blk(n)
print 'Time for constructing the matrix: %8.2f sec' % (time.clock() - t1, )
print L.nnz
# ---------------------------------------------------------------------------------------
t1 = time.clock()
jdsym.jdsym(L.to_sss(), None, None, 5, 0.0, 1e-8, 100, itsolvers.qmrs, clvl=1)
print 'Time spend in jdsym: %8.2f sec' % (time.clock() - t1, )
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