# [SciPy-user] csc, csr sparse complex matrix problems.

Mark Starnes m.starnes at imperial.ac.uk
Wed Dec 13 21:09:38 CST 2006

```Hi everyone,

I've been trying to get this simple example to work for a couple of days
now, to no avail.  I noticed at
http://projects.scipy.org/scipy/scipy/ticket/329 that there seem to be
come problems with csc and complex values but I'm hoping they're
unrelated and someone can help me sort this problem!  I couldn't get the
csc matrix to work at all here - the csr matrix was having a go and
getting the right answer but now fails too!  Anyway, here's the code.
I'm using Python2.4.3 on winxp with Scipy0.5.2, Numpy 1.0.1.

Any help will be appreciated.

Best regards,

Mark Starnes.

***

import numpy as n
import scipy as s
from scipy.linsolve import spsolve
from scipy import linalg as la
from numpy import zeros,complex64

# solve kx=f for x, where
#
#/                    \  /    \    /       \
#| 1+1i  2+2i  3+3i   | |   2  |   | -5+3i  |
#|                    | |      |   |        |
#| 2     3     4+4i   | | 3+2i | = | 1-6i   |
#|                    | |      |   |        |
#| 4+9i 5+10i  2+11i  | |  -3  |   | -3+25i |
#\                    /  \    /    \       /
#

k0=n.array([[1+1j,2+2j,3+3j],[2,3,4+4j],[4+9j,5+10j,2+11j]])
f0=[-5+3j,1-6j,-3+25j]

# Test numpy routine.

k=n.mat(k0)
f=n.mat(f0).T
fsol=s.dot(la.inv(k),f)
print fsol
print k*fsol
# result should = [2, 3+2j, -3].  Numpy passes.

# Test Scipy sparse routines.
k=s.sparse.csc_matrix((3,3),dtype='F')
k[0,0]=1+1j ; k[0,1]=2+2j  ; k[0,2]=3+3j ;
k[1,0]=2    ; k[1,1]=3     ; k[1,2]=4+4j ;
k[2,0]=4+9j ; k[2,1]=5+10j ; k[2,2]=2+11j;

f=zeros((3),complex64)
f[0]=-5+3j
f[1]=1-6j
f[2]=-3+25j

#fsol2=spsolve(k,f)   # this crashes python with typeD, AND with type F
#print fsol2
#print k.dot(fsol2)

k=s.sparse.csr_matrix((3,3),dtype='F')
k[0,0]=1+1j ; k[0,1]=2+2j  ; k[0,2]=3+3j ;
k[1,0]=2    ; k[1,1]=3     ; k[1,2]=4+4j ;
k[2,0]=4+9j ; k[2,1]=5+10j ; k[2,2]=2+11j;

fsol3=spsolve(k,f)   # this crashes python with typeD, originally ok
with type F
print fsol3
print k.dot(fsol3)

```