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Topic: Solving sparse Ax=b without certain eigenvector spaces
Replies: 11   Last Post: Aug 8, 2014 3:25 AM

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Posts: 5
Registered: 8/2/14
Solving sparse Ax=b without certain eigenvector spaces
Posted: Aug 2, 2014 6:13 PM
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Hi, I'm trying to solve a sparse Ax=b problem. The size of A is about 10^4 by 10^4. A is pretty singular and the first a few eigenvalues of A is about 10^(-12), 10^(-6) and 10^(-4). I'm able to find the first a few eigenvalues and eigenvectors using the command eigs, which takes only one or two seconds. Now I want to find x, such that Ax=b, but I want to exclude the first three eigenvectors.

Are there any simple ways that allow me to do this?

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