scale_linalgebra::linalgebra_solvelineq Interface Reference

Solve a linear equation Ax=b using a direct solver. More...

Public Member Functions
subroutine	linalgebra_solvelineq_b1d (a, b, x)
	Solve a linear equation Ax=b using a direct solver.
subroutine	linalgebra_solvelineq_b2d (a, b, x)
	Solve a linear equation Ax=b using a direct solver where b is a matrix.

Detailed Description

Solve a linear equation Ax=b using a direct solver.

Definition at line 33 of file scale_linalgebra.F90.

Member Function/Subroutine Documentation

linalgebra_solvelineq_b1d()

subroutine scale_linalgebra::linalgebra_solvelineq::linalgebra_solvelineq_b1d	(	real(rp), dimension(:,:), intent(in)	a,
		real(rp), dimension(:), intent(in)	b,
		real(rp), dimension(size(b)), intent(out)	x )

Solve a linear equation Ax=b using a direct solver.

Parameters

[in]	a	Coefficient matrix
[in]	b	Vector in the right-hand side
[out]	x	Solution vector of linear equation Ax=b

Definition at line 107 of file scale_linalgebra.F90.

    implicit none
    real(RP), intent(in) :: A(:,:)        !< Coefficient matrix
    real(RP), intent(in) :: b(:)          !< Vector in the right-hand side
    real(RP), intent(out) :: x(size(b))   !< Solution vector of linear equation Ax=b
 
    real(RP) :: A_lu(size(A,1),size(A,2))
    integer :: ipiv(size(A,1))
    integer :: n, info
 
    !--------------------------------------------------------------------------- 
 
    a_lu = a
    n = size(a,1)
 
    call dgetrf(n, n, a_lu, n, ipiv, info)
    if (info /=0 ) then
      log_error("linalgebra_SolveLinEq",*) "Matrix is singular"
      call prc_abort
    end if
 
    x(:) = b
    call dgetrs('N', n, 1, a_lu, n, ipiv, x, n, info)
    if (info /=0 ) then
      log_error("linalgebra_SolveLinEq",*)  "Matrix inversion is failed"
      call prc_abort
    end if
 
    return

linalgebra_solvelineq_b2d()

subroutine scale_linalgebra::linalgebra_solvelineq::linalgebra_solvelineq_b2d	(	real(rp), dimension(:,:), intent(in)	a,
		real(rp), dimension(:,:), intent(in)	b,
		real(rp), dimension(size(b,1),size(b,2)), intent(out)	x )

Solve a linear equation Ax=b using a direct solver where b is a matrix.

Parameters

[in]	a	Coefficient matrix
[in]	b	Matrix in the right-hand side
[out]	x	Matrix storing solution of linear equation Ax=b

Definition at line 140 of file scale_linalgebra.F90.

    implicit none
    real(RP), intent(in) :: A(:,:)                   !< Coefficient matrix
    real(RP), intent(in) :: b(:,:)                   !< Matrix in the right-hand side
    real(RP), intent(out) :: x(size(b,1),size(b,2))  !< Matrix storing solution of linear equation Ax=b
 
    real(RP) :: A_lu(size(A,1),size(A,2))
    integer :: ipiv(size(A,1))
    integer :: n, info
 
    !--------------------------------------------------------------------------- 
 
    a_lu = a
    n = size(a,1)
 
    call dgetrf(n, n, a_lu, n, ipiv, info)
    if (info /=0 ) then
      log_error("linalgebra_SolveLinEq",*) "Matrix is singular"
      call prc_abort
    end if
 
    x(:,:) = b
    call dgetrs('N', n, size(b,2), a_lu, n, ipiv, x, n, info)
    if (info /=0 ) then
      log_error("linalgebra_SolveLinEq",*)  "Matrix inversion is failed"
      call prc_abort
    end if
 
    return

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The documentation for this interface was generated from the following file:

• scale_linalgebra.F90