.Modelica_LinearSystems2.Math.Matrices.LAPACK.dgetrs

Information

Lapack documentation:

   Purpose
   =======

   DGETRS solves a system of linear equations
      A * X = B  or  A' * X = B
   with a general N-by-N matrix A using the LU factorization computed
   by DGETRF.

   Arguments
   =========

   TRANS   (input) CHARACTER*1
           Specifies the form of the system of equations:
           = 'N':  A * X = B  (No transpose)
           = 'T':  A'* X = B  (Transpose)
           = 'C':  A'* X = B  (Conjugate transpose = Transpose)
   N       (input) INTEGER
           The order of the matrix A.  N >= 0.
   NRHS    (input) INTEGER
           The number of right hand sides, i.e., the number of columns
           of the matrix B.  NRHS >= 0.
   A       (input) DOUBLE PRECISION array, dimension (LDA,N)
           The factors L and U from the factorization A = P*L*U
           as computed by DGETRF.
   LDA     (input) INTEGER
           The leading dimension of the array A.  LDA >= max(1,N).
   IPIV    (input) INTEGER array, dimension (N)
           The pivot indices from DGETRF; for 1<=i<=N, row i of the
           matrix was interchanged with row IPIV(i).
   B       (input/output) DOUBLE PRECISION array, dimension (LDB,NRHS)
           On entry, the right hand side matrix B.
           On exit, the solution matrix X.
   LDB     (input) INTEGER
           The leading dimension of the array B.  LDB >= max(1,N).
   INFO    (output) INTEGER
           = 0:  successful exit
           < 0:  if INFO = -i, the i-th argument had an illegal value

   =====================================================================  

Interface

function dgetrs
  input Real LU[:, size(LU, 1)] "LU factorization of dgetrf of a square matrix";
  input Integer pivots[size(LU, 1)] "Pivot vector of dgetrf";
  input Real B[size(LU, 1), :] "Right hand side matrix B";
  output Real X[size(B, 1), size(B, 2)] = B "Solution matrix X";
end dgetrs;