X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=dunshire%2Fmatrices.py;h=94f841d39f888392624077afd12bcdcb7e0c3c19;hb=cb34e104961ce1da242017a0e5ebf60c3fe18a1d;hp=13e8150f5c807914782dbcb49733f36be513912c;hpb=381ee9f23d45d7094c9713c846c6119bb64c0807;p=dunshire.git

diff --git a/dunshire/matrices.py b/dunshire/matrices.py
index 13e8150..94f841d 100644
--- a/dunshire/matrices.py
+++ b/dunshire/matrices.py
@@ -3,6 +3,7 @@ Utility functions for working with CVXOPT matrices (instances of the
 class:`cvxopt.base.matrix` class).
 """
 
+from copy import copy
 from math import sqrt
 from cvxopt import matrix
 from cvxopt.lapack import gees, gesdd, syevr
@@ -140,7 +141,10 @@ def eigenvalues(symmat):
 
     domain_dim = symmat.size[0]
     eigs = matrix(0, (domain_dim, 1), tc='d')
-    syevr(symmat, eigs)
+
+    # Create a copy of ``symmat`` here because ``syevr`` clobbers it.
+    dummy = copy(symmat)
+    syevr(dummy, eigs)
     return list(eigs)
 
 
@@ -418,10 +422,6 @@ def condition_number(mat):
     Examples
     --------
 
-    >>> condition_number(identity(1, typecode='d'))
-    1.0
-    >>> condition_number(identity(2, typecode='d'))
-    1.0
     >>> condition_number(identity(3, typecode='d'))
     1.0