PROGRAM LA_SGESVX_EXAMPLE ! -- LAPACK95 EXAMPLE DRIVER ROUTINE (VERSION 1.0) -- ! UNI-C, DENMARK ! DECEMBER, 1999 ! ! .. "Use Statements" .. USE LA_PRECISION, ONLY: WP => SP USE F95_LAPACK, ONLY: LA_GESVX ! .. "Implicit Statement" .. IMPLICIT NONE ! .. "Local Scalars" .. INTEGER :: I, J, N, NRHS, INFO ! .. "Local Arrays" .. INTEGER, ALLOCATABLE :: IPIV(:) REAL(WP) :: RCOND, RPVGRW REAL(WP), ALLOCATABLE :: A(:,:), AA(:,:), B(:,:), X(:,:),BB(:,:), FERR(:), BERR(:) REAL(WP), ALLOCATABLE :: RR(:,:) ! .. "Executable Statements" .. WRITE (*,*) 'SGESVX Example Program Results.' ! WRITE(*,*)'Size of matrix A, N = ?' ! READ ( *, * ) N N = 2 ! WRITE(*,*)'Number of right hand sides, NRHS = ?' ! READ ( *, * ) NRHS NRHS = 1 ALLOCATE( A(N,N), AA(N,N), B(N,NRHS), X(N,NRHS),BB(N,NRHS), IPIV(N), RR(N,N), FERR(NRHS), BERR(NRHS) ) ! OPEN(UNIT=21,FILE='gesv.ma',STATUS='UNKNOWN') ! DO J=1,N ! DO I=1,N ! READ(21,'(F2.0)') AA(I,J) ! ENDDO ! ENDDO ! CLOSE(21) AA(1,1) = 0; AA(1,2) = 1; AA(2,1) = 0; AA(2,2) = 1 ! DO I = 1, N; READ (*, *) (RR(I, J), J = 1, N); ENDDO ! AA=RR DO J = 1, NRHS; BB(:,J) = SUM( AA, DIM=2)*J; ENDDO WRITE(*,*) 'The matrix A:' DO I=1,N; WRITE(*,"(4(I3,1X),I3,1X)") INT(AA(I,:)); ENDDO WRITE(*,*) 'The RHS matrix B:' DO I=1,N; WRITE(*,"(2(I3,1X),I3,1X)") INT(BB(I,:)); ENDDO WRITE(*,*) 'CALL LA_GESVX( A, B, X, FERR=FERR, BERR=BERR, ', & 'RCOND=RCOND, RPVGRW=RPVGRW, INFO =INFO )' A=AA; B=BB CALL LA_GESVX( A, B, X, FERR=FERR, BERR=BERR, RCOND=RCOND, & RPVGRW=RPVGRW, INFO=INFO ) WRITE(*,*) 'INFO = ', INFO WRITE(*,*) 'FERR = ', FERR WRITE(*,*) 'BERR = ', BERR WRITE(*,*) 'RCOND = ', RCOND WRITE(*,*) 'RPVGRW = ', RPVGRW WRITE(*,*) '\noindent' WRITE(*,*) 'The solution of the system $ A\,X = B $ is:' WRITE(*,*) '$$ X = \left( \begin{array}{rrr}' DO I=1,N; WRITE(*,"(2(F9.5,' & '),F9.5,' \\')") X(I,:); ENDDO WRITE(*,*) '\end{array} \right). $$' WRITE(*,*) 'The matrix A on exit:' DO I=1,N; WRITE(*,*) AA(I,:); ENDDO END PROGRAM LA_SGESVX_EXAMPLE