Efficiently finding a single row of the inverse of a symmetric (not Hermitian) complex matrix











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I want to find, at many frequencies $w$, the response at a few nodes to input at one node in a 1-D kinematic system with constraints, i.e. find (part of) $mathbf x$ s.t. $$left(- w^2 mathbf M + jw mathbf C + mathbf Kright) mathbf x = [1,0,0,...]^T$$



where, due to already comprehending the constraint equations, $mathbf M$, $mathbf C$, and $mathbf K$ are all real symmetric, on the order of 10 x 10, but not n- or block-diagonal, or sparse enough to be helpful. $mathbf M$ is positive definite, but the others (and the resulting complex matrix) are not.



Question 1:



Is there some way to take advantage of the symmetry (similar to Cholesky) and/or the limited number of required outputs?



Question 2:



Is there some way to incrementally advance a solution for changing $w$?










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    I want to find, at many frequencies $w$, the response at a few nodes to input at one node in a 1-D kinematic system with constraints, i.e. find (part of) $mathbf x$ s.t. $$left(- w^2 mathbf M + jw mathbf C + mathbf Kright) mathbf x = [1,0,0,...]^T$$



    where, due to already comprehending the constraint equations, $mathbf M$, $mathbf C$, and $mathbf K$ are all real symmetric, on the order of 10 x 10, but not n- or block-diagonal, or sparse enough to be helpful. $mathbf M$ is positive definite, but the others (and the resulting complex matrix) are not.



    Question 1:



    Is there some way to take advantage of the symmetry (similar to Cholesky) and/or the limited number of required outputs?



    Question 2:



    Is there some way to incrementally advance a solution for changing $w$?










    share|cite|improve this question


























      up vote
      0
      down vote

      favorite









      up vote
      0
      down vote

      favorite











      I want to find, at many frequencies $w$, the response at a few nodes to input at one node in a 1-D kinematic system with constraints, i.e. find (part of) $mathbf x$ s.t. $$left(- w^2 mathbf M + jw mathbf C + mathbf Kright) mathbf x = [1,0,0,...]^T$$



      where, due to already comprehending the constraint equations, $mathbf M$, $mathbf C$, and $mathbf K$ are all real symmetric, on the order of 10 x 10, but not n- or block-diagonal, or sparse enough to be helpful. $mathbf M$ is positive definite, but the others (and the resulting complex matrix) are not.



      Question 1:



      Is there some way to take advantage of the symmetry (similar to Cholesky) and/or the limited number of required outputs?



      Question 2:



      Is there some way to incrementally advance a solution for changing $w$?










      share|cite|improve this question















      I want to find, at many frequencies $w$, the response at a few nodes to input at one node in a 1-D kinematic system with constraints, i.e. find (part of) $mathbf x$ s.t. $$left(- w^2 mathbf M + jw mathbf C + mathbf Kright) mathbf x = [1,0,0,...]^T$$



      where, due to already comprehending the constraint equations, $mathbf M$, $mathbf C$, and $mathbf K$ are all real symmetric, on the order of 10 x 10, but not n- or block-diagonal, or sparse enough to be helpful. $mathbf M$ is positive definite, but the others (and the resulting complex matrix) are not.



      Question 1:



      Is there some way to take advantage of the symmetry (similar to Cholesky) and/or the limited number of required outputs?



      Question 2:



      Is there some way to incrementally advance a solution for changing $w$?







      numerical-linear-algebra symmetric-matrices






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      share|cite|improve this question













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      edited 2 days ago

























      asked Nov 16 at 16:47









      TrollShadowknight

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