Matrix Inversion in LAPACK

Here is a Fortran program which performs matrix inversion using the LU decomposition method:  INVERSE_MATRIX.F

It is compiled via:

gfortran -o INVERSE_MATRIX INVERSE_MATRIX.F -llapack

It compiles & runs under both Ubuntu & Cygwin.

See also: http://www.nag.com/numeric/fl/nagdoc_fl23/examples/source/f07ajfe.f90

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The INVERSE_MATRIX.F program uses the subroutines: DGETRF & DGETRI

DGETRF computes an LU factorization of a general M-by-N matrix A using partial pivoting with row interchanges.

DGETRI computes the inverse of a matrix using the LU factorization computed by DGETRF.

This method inverts U and then computes inv(A) by solving the system inv(A)*L = inv(U) for inv(A).

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Here is a similar C++ program:  matrix_inverse.cpp 

It is compiled as:

gcc -o matrix_inverse matrix_inverse.cpp -llapack -lstdc++

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See also:  Python Matrix Inversion

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Tom Irvine

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