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| author | stainer_t <thomas.stainer@oecd-nea.org> | 2025-09-08 13:48:49 +0200 |
|---|---|---|
| committer | stainer_t <thomas.stainer@oecd-nea.org> | 2025-09-08 13:48:49 +0200 |
| commit | 7dfcc480ba1e19bd3232349fc733caef94034292 (patch) | |
| tree | 03ee104eb8846d5cc1a981d267687a729185d3f3 /Utilib/src/ALPINVD.f | |
Initial commit from Polytechnique Montreal
Diffstat (limited to 'Utilib/src/ALPINVD.f')
| -rw-r--r-- | Utilib/src/ALPINVD.f | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/Utilib/src/ALPINVD.f b/Utilib/src/ALPINVD.f new file mode 100644 index 0000000..69b4bc5 --- /dev/null +++ b/Utilib/src/ALPINVD.f @@ -0,0 +1,47 @@ +*DECK ALPINVD + SUBROUTINE ALPINVD(M,N,A,AINV) +* +*----------------------------------------------------------------------- +* +*Purpose: +* pseudo inversion of a non singular matrix using Gaussian elimination +* with partial pivoting. Double precision version. +* +*Copyright: +* Copyright (C) 2015 Ecole Polytechnique de Montreal +* This library is free software; you can redistribute it and/or +* modify it under the terms of the GNU Lesser General Public +* License as published by the Free Software Foundation; either +* version 2.1 of the License, or (at your option) any later version. +* +*Author(s): A. Hebert +* +*Parameters: input +* M first dimension of matrix A. +* N second dimension of matrix A. +* A coefficient matrix to be inverted. +* +*Parameters: output +* AINV pseudo inverted matrix. +* +*----------------------------------------------------------------------- +* + IMPLICIT DOUBLE PRECISION(A-H,O-Z) +*---- +* SUBROUTINE ARGUMENTS +*---- + INTEGER M,N + DOUBLE PRECISION A(M,N),AINV(N,M) +*---- +* LOCAL VARIABLES +*---- + DOUBLE PRECISION, DIMENSION(:,:), ALLOCATABLE :: B +* + ALLOCATE(B(N,N)) + B=MATMUL(TRANSPOSE(A),A) + CALL ALINVD(N, B, N, IER) + IF(IER.NE.0) CALL XABORT('ALPINVD: PSEUDO INVERSION FAILURE.') + AINV=MATMUL(B, TRANSPOSE(A)) + DEALLOCATE(B) + RETURN + END |