Program f01dgfe
! F01DGF Example Program Text
! Mark 30.0 Release. NAG Copyright 2024.
! .. Use Statements ..
Use nag_library, Only: f01dgf, nag_wp, x04caf
! .. Implicit None Statement ..
Implicit None
! .. Parameters ..
Integer, Parameter :: nin = 5, nout = 6
! .. Local Scalars ..
Real (Kind=nag_wp) :: alpha
Integer :: i, ifail, lda, ldb, n
Character (1) :: side, transa, uplo
! .. Local Arrays ..
Real (Kind=nag_wp), Allocatable :: a(:,:), b(:,:)
! .. Executable Statements ..
Write (nout,*) 'F01DGF Example Program Results'
! Skip heading in data file
Read (nin,*)
Write (nout,*)
Flush (nout)
! Values for side, uplo, and transa
Read (nin,*) side, uplo, transa
! Order of square matrices
Read (nin,*) n
lda = n
ldb = n
! Scaling constant alpha
Read (nin,*) alpha
! Allocate memory for local arrays
Allocate (a(n,n),b(n,n))
! Read input matrix A from data file
If (uplo=='U') Then
Read (nin,*)(a(i,i:n),i=1,n)
Else
Read (nin,*)(a(i,1:i),i=1,n)
End If
! Read input matrix B from data file
If (uplo=='U') Then
Read (nin,*)(b(i,i:n),i=1,n)
Else
Read (nin,*)(b(i,1:i),i=1,n)
End If
! ifail: behaviour on error exit
! = 0 for hard exit, =1 for quiet-soft, =-1 for noisy-soft
ifail = 0
! Find B=alpha*A*B
Call f01dgf(side,uplo,transa,n,alpha,a,lda,b,ldb,ifail)
! Print the solution
If (ifail==0) Then
If (transa=='N') Then
Call x04caf(uplo,'N',n,n,b,n,'Solution matrix B',ifail)
Else
Call x04caf('G','N',n,n,b,n,'Solution matrix B',ifail)
End If
End If
End Program f01dgfe