I have a complex 2X2 matrix for which I'd like to calculate the determinant.
mpmath's det function gives a determinant of zero even though the matrix is
non-singular. We can get the correct value by multiplying term-by-term.
What steps will reproduce the problem?
#========================
from __future__ import division
import numpy as np
import sympy.mpmath as mpmath
m3 = np.matrix([[ 5.18895807e-12 +0.00000000e+00j,
1.92716917e+11 +0.00000000e+00j],
[ 0.00000000e+00 -1.93643371e-11j,
0.00000000e+00 -5.16413237e+10j]])
m = mpmath.matrix(m3)
print np.linalg.det(m3)
print mpmath.det(m)
print m[0,0]*m[1,1]- m[1,0]*m[0,1]
#========================
What is the expected output? What do you see instead?
The output is :
3.4638706823j
0
(0.0 + 3.46387068230212j)
Expected output:
3.4638706823j
(0.0 + 3.46387068230212j)
(0.0 + 3.46387068230212j)
What version of the product are you using? On what operating system?
0.17, ubuntu
Please provide any additional information below.
The same problem occurs when trying to calculate the inverse of the matrix.
Original issue reported on code.google.com by Sameer.G...@gmail.com on 18 Aug 2012 at 4:34
Original issue reported on code.google.com by
Sameer.G...@gmail.com
on 18 Aug 2012 at 4:34