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Instant-use add-on functions for the Wolfram Language
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Convert a Hermitian-definite matrix pencil into a matrix with the same eigenvalues
ResourceFunction["DefinitePencilReduce"][{m,a}] yields a list of matrices {s,t}, where s is a Hermitian matrix with the same eigenvalues as the Hermitian definite matrix pencil {m,a}, and t is a transformation matrix that transforms the eigenvectors of s into the eigenvectors of {m,a}. |
A symmetric definite pencil:
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Reduce the pencil:
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Compute the eigenvalues of the transformed matrix:
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These are the same as the eigenvalues of the original pencil:
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Compute the normalized eigenvectors of the transformed matrix:
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These are the same as the eigenvectors of the original pencil, up to a normalization constant:
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A machine precision symmetric definite pencil:
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Reduce the pencil:
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Compute the eigenvalues of the transformed matrix:
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These are the same as the eigenvalues of the original pencil:
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Compute the normalized eigenvectors of the transformed matrix:
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These are the same as the eigenvectors of the original pencil, up to a normalization constant:
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Reduce an exact symmetric definite pencil:
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Reduce a symmetric definite pencil with 24-digit precision arithmetic::
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A random symmetric definite pencil:
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Reduce the pencil:
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A random Hermitian definite pencil:
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Reduce the pencil:
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Use the "Cholesky" method to reduce the definite pencil:
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Use the "Eigensystem" method to reduce the definite pencil:
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A definite pencil:
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Reduce the definite pencil:
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Verify that m is given by ConjugateTranspose[t].s.t:
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Verify that a is given by ConjugateTranspose[t].t:
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DefinitePencilReduce is left unevaluated if the argument is not a definite pencil:
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This work is licensed under a Creative Commons Attribution 4.0 International License