Re: [math] EigenDecompositionImpl

2011-08-24 Thread Luc Maisonobe
Le 24/08/2011 00:59, Greg Sterijevski a écrit : Should I open a ticket, or do you want to handle this? Please open a ticket. For the moment, I am busy in other parts (integration, geometry and ODE) and don't fiddle with linear algebra. Luc On Tue, Aug 23, 2011 at 5:47 PM, Luc Maisonobewro

Re: [math] EigenDecompositionImpl

2011-08-23 Thread Greg Sterijevski
Should I open a ticket, or do you want to handle this? On Tue, Aug 23, 2011 at 5:47 PM, Luc Maisonobe wrote: > Le 24/08/2011 00:44, Greg Sterijevski a écrit : > > I understand you want to support the general case, but why should it >> necessitate instantiating a ref. >> > > You are right, we cou

Re: [math] EigenDecompositionImpl

2011-08-23 Thread Luc Maisonobe
Le 24/08/2011 00:44, Greg Sterijevski a écrit : I understand you want to support the general case, but why should it necessitate instantiating a ref. You are right, we could go with an array allocated only upon request. Luc On Tue, Aug 23, 2011 at 5:29 PM, Luc Maisonobewrote: Le 23/08/201

Re: [math] EigenDecompositionImpl

2011-08-23 Thread Greg Sterijevski
I understand you want to support the general case, but why should it necessitate instantiating a ref. On Tue, Aug 23, 2011 at 5:29 PM, Luc Maisonobe wrote: > Le 23/08/2011 20:45, Greg Sterijevski a écrit : > > Hello All, >> >> Since math gives eigendecomposition for symmetrics, why even allocate

Re: [math] EigenDecompositionImpl

2011-08-23 Thread Luc Maisonobe
Le 23/08/2011 20:45, Greg Sterijevski a écrit : Hello All, Since math gives eigendecomposition for symmetrics, why even allocate the array imagEigenvalues ? What am I missing? For now, we are limited to symmetric matrices because we did not implement anything else. However, we did prepare the

[math] EigenDecompositionImpl

2011-08-23 Thread Greg Sterijevski
Hello All, Since math gives eigendecomposition for symmetrics, why even allocate the array imagEigenvalues ? What am I missing? Thanks, -Greg

Re: [Math] EigenDecompositionImpl#getEigenvector()

2009-09-20 Thread Phil Steitz
Ted Dunning wrote: > Numerical issues should not impinge on a computation this small. > > For reference, I replicated your computation and found reasonable > eigenvalues and vectors: > >> m = matrix(c(0,1,-1,1,1,0,-1,0,1), nrow=3) >> m > [,1] [,2] [,3] > [1,]01 -1 > [2,]11

Re: [Math] EigenDecompositionImpl#getEigenvector()

2009-09-19 Thread Axel
On Sun, Sep 20, 2009 at 7:51 AM, Ted Dunning wrote: > Numerical issues should not impinge on a computation this small. ... > Your usage appears to be in accord with the suggested usage, but have you > tried it with a tolerance of, say, 1e-3? This gives the same result: {(NaN); (NaN); (NaN)} -- Ax

Re: [Math] EigenDecompositionImpl#getEigenvector()

2009-09-19 Thread Ted Dunning
Numerical issues should not impinge on a computation this small. For reference, I replicated your computation and found reasonable eigenvalues and vectors: > m = matrix(c(0,1,-1,1,1,0,-1,0,1), nrow=3) > m [,1] [,2] [,3] [1,]01 -1 [2,]110 [3,] -101 > eig(m) Err

[Math] EigenDecompositionImpl#getEigenvector()

2009-09-19 Thread Axel
Hello I'm trying to calculate the Eigenvectors of this Wikipedia example: http://en.wikipedia.org/wiki/Eigenvalue_algorithm#Identifying_eigenvectors with this JUnit method: public void testEigenDecomposition() { double[][] m = { { 0.0, 1.0, -1.0 }, { 1.0, 1.0, 0.0 }, { -1.0, 0.0, 1.0 } };