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2012-01-09 11:26:39 +0100 commented answer Calculating eigenvectors in C

Hi Volker, thanks for chiming in. Your reply had very valuable hints! Moreover, I don't know if you'd be open to the possibility and please forgive me if here is not the best place to bring the subject up, but I could use some help sorting this problem out on a consulting basis. Would you have the availability and be open to work with me on this specific problem? If yes, please give a way to contact you where we could discuss details.

2012-01-08 21:44:25 +0100 answered a question Calculating eigenvectors in C

Looking into the source code I found /Applications/Sage-4.7.2-OSX-64bit-10.6.app/Contents/Resources/sage/devel/sage-main/sage/matrix/matrix2.c

and

/Applications/Sage-4.7.2-OSX-64bit-10.6.app/Contents/Resources/sage/devel/sage-main/sage/matrix/matrix2.pyx

both files contain references to eigenvectors_right(), so it may be safe to assume that somehow I can embed one of these header files and the respective library in my C program and compute the eigenvectors for a Stochastic matrix.

Would you know what is the library that goes with matrix2.c? Also, any suggestion in the best way to use it from my C program?

Thank you,

Dalmo

2012-01-08 21:14:46 +0100 commented answer Calculating eigenvectors in C

Hi Shashank, thanks for the reply!! In my case I was actually looking for running an self contained C binary that does not need to rely on Sage on the background. The program would often calculate the eigenvectors and use the result to determine the vector space. Knowing what C function is behind eigenvectors_right() would be ideal. I tried using LAPACK but never managed to get it to calculate the eigenvectors correctly, since the matrix is Stochastic and often the diagonal is made of zeros. Sage worked beautifully, thus my question and search for what lies under the hood.

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2012-01-08 20:47:31 +0100 asked a question Calculating eigenvectors in C

Using Sage's notebook I was able to successfully calculate the eigenvectors of a Stochastic matrix with the method eigenvectors_right(). Now, if possible, I'd like to be able to perform the same kind calculation from a program in C. Does anyone know what framework and function is behind the eigenvectors_right() method? And would I be able to call it directly from a C program?

Thank you,

Dalmo