! C06FJF Example Program Text ! Mark 24 Release. NAG Copyright 2012. Module c06fjfe_mod ! C06FJF Example Program Module: ! Parameters and User-defined Routines ! .. Use Statements .. Use nag_library, Only: nag_wp ! .. Implicit None Statement .. Implicit None ! .. Parameters .. Integer, Parameter :: nin = 5, nout = 6 Contains Subroutine readxy(nin,x,y,n1,n2) ! Read 2-dimensional complex data ! .. Scalar Arguments .. Integer, Intent (In) :: n1, n2, nin ! .. Array Arguments .. Real (Kind=nag_wp), Intent (Out) :: x(n1,n2), y(n1,n2) ! .. Local Scalars .. Integer :: i, j ! .. Executable Statements .. Do i = 1, n1 Read (nin,*)(x(i,j),j=1,n2) Read (nin,*)(y(i,j),j=1,n2) End Do Return End Subroutine readxy Subroutine writxy(nout,x,y,n1,n2) ! Print 2-dimensional complex data ! .. Scalar Arguments .. Integer, Intent (In) :: n1, n2, nout ! .. Array Arguments .. Real (Kind=nag_wp), Intent (In) :: x(n1,n2), y(n1,n2) ! .. Local Scalars .. Integer :: i, j ! .. Executable Statements .. Do i = 1, n1 Write (nout,*) Write (nout,99999) 'Real ', (x(i,j),j=1,n2) Write (nout,99999) 'Imag ', (y(i,j),j=1,n2) End Do Return 99999 Format (1X,A,7F10.3/(6X,7F10.3)) End Subroutine writxy End Module c06fjfe_mod Program c06fjfe ! C06FJF Example Main Program ! .. Use Statements .. Use nag_library, Only: c06fjf, c06gcf, nag_wp Use c06fjfe_mod, Only: nin, nout, readxy, writxy ! .. Implicit None Statement .. Implicit None ! .. Local Scalars .. Integer :: ieof, ifail, lwork, n, ndim ! .. Local Arrays .. Real (Kind=nag_wp), Allocatable :: work(:), x(:), y(:) Integer, Allocatable :: nd(:) ! .. Intrinsic Procedures .. Intrinsic :: maxval, product ! .. Executable Statements .. Write (nout,*) 'C06FJF Example Program Results' ! Skip heading in data file Read (nin,*) loop: Do Read (nin,*,Iostat=ieof) ndim If (ieof<0) Exit loop Allocate (nd(ndim)) Read (nin,*) nd(1:ndim) n = product(nd(1:ndim)) lwork = 3*maxval(nd(1:ndim)) Allocate (x(n),y(n),work(lwork)) Call readxy(nin,x,y,nd(1),nd(2)) Write (nout,*) Write (nout,*) 'Original data values' Call writxy(nout,x,y,nd(1),nd(2)) ! ifail: behaviour on error exit ! =0 for hard exit, =1 for quiet-soft, =-1 for noisy-soft ifail = 0 ! Compute transform Call c06fjf(ndim,nd,n,x,y,work,lwork,ifail) Write (nout,*) Write (nout,*) 'Components of discrete Fourier transform' Call writxy(nout,x,y,nd(1),nd(2)) ! Compute inverse transform Call c06gcf(y,n,ifail) Call c06fjf(ndim,nd,n,x,y,work,lwork,ifail) Call c06gcf(y,n,ifail) Write (nout,*) Write (nout,*) 'Original sequence as restored by inverse transform' Call writxy(nout,x,y,nd(1),nd(2)) Deallocate (x,y,work,nd) End Do loop End Program c06fjfe