X-Git-Url: https://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=dunshire%2Fmatrices.py;h=6d5bbc8f667dce05feb93ec9fabcf42340f1157e;hb=299bf2d606eb245ec78f2e20826836c0bb5bfc07;hp=13e8150f5c807914782dbcb49733f36be513912c;hpb=381ee9f23d45d7094c9713c846c6119bb64c0807;p=dunshire.git diff --git a/dunshire/matrices.py b/dunshire/matrices.py index 13e8150..6d5bbc8 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) @@ -326,12 +330,12 @@ def norm(matrix_or_vector): -------- >>> v = matrix([1,1]) - >>> print('{:.5f}'.format(norm(v))) - 1.41421 + >>> norm(v) + 1.414... >>> A = matrix([1,1,1,1], (2,2)) >>> norm(A) - 2.0 + 2.0... """ return sqrt(inner_product(matrix_or_vector, matrix_or_vector)) @@ -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