Program c06ppfe
! C06PPF Example Program Text
! Mark 30.1 Release. NAG Copyright 2024.
! .. Use Statements ..
Use nag_library, Only: c06ppf, nag_wp
! .. Implicit None Statement ..
Implicit None
! .. Parameters ..
Integer, Parameter :: nin = 5, nout = 6
! .. Local Scalars ..
Integer :: i, ieof, ifail, j, m, n
! .. Local Arrays ..
Real (Kind=nag_wp), Allocatable :: work(:), x(:)
! .. Executable Statements ..
Write (nout,*) 'C06PPF Example Program Results'
! Skip heading in data file
Read (nin,*)
loop: Do
Read (nin,*,Iostat=ieof) m, n
If (ieof<0) Then
Exit loop
End If
Allocate (work((m+2)*(n+2)+11),x(m*(n+2)))
Do j = 1, m
Read (nin,*)(x(i*m+j),i=0,n-1)
End Do
Write (nout,*)
Write (nout,*) 'Original data values'
Write (nout,*)
Do j = 1, m
Write (nout,99999) ' ', (x(i*m+j),i=0,n-1)
End Do
! ifail: behaviour on error exit
! =0 for hard exit, =1 for quiet-soft, =-1 for noisy-soft
ifail = 0
Call c06ppf('F',m,n,x,work,ifail)
Write (nout,*)
Write (nout,*) &
'Discrete Fourier transforms in complex Hermitian format'
Do j = 1, m
Write (nout,*)
Write (nout,99999) 'Real ', (x(2*i*m+j),i=0,n/2)
Write (nout,99999) 'Imag ', (x((2*i+1)*m+j),i=0,n/2)
End Do
Write (nout,*)
Write (nout,*) 'Fourier transforms in full complex form'
Do j = 1, m
Write (nout,*)
Write (nout,99999) 'Real ', (x(2*i*m+j),i=0,n/2), &
(x(2*(n-i)*m+j),i=n/2+1,n-1)
Write (nout,99999) 'Imag ', (x((2*i+1)*m+j),i=0,n/2), &
(-x((2*(n-i)+1)*m+j),i=n/2+1,n-1)
End Do
Call c06ppf('B',m,n,x,work,ifail)
Write (nout,*)
Write (nout,*) 'Original data as restored by inverse transform'
Write (nout,*)
Do j = 1, m
Write (nout,99999) ' ', (x(i*m+j),i=0,n-1)
End Do
Deallocate (x,work)
End Do loop
99999 Format (1X,A,9(:,1X,F10.4))
End Program c06ppfe