Program c06pafe ! C06PAF Example Program Text ! Mark 24 Release. NAG Copyright 2012. ! .. Use Statements .. Use nag_library, Only: c06paf, nag_wp ! .. Implicit None Statement .. Implicit None ! .. Parameters .. Integer, Parameter :: nin = 5, nout = 6 ! .. Local Scalars .. Integer :: ieof, ifail, j, n, nj ! .. Local Arrays .. Real (Kind=nag_wp), Allocatable :: work(:), x(:), xx(:) ! .. Executable Statements .. Write (nout,*) 'C06PAF Example Program Results' ! Skip heading in data file Read (nin,*) loop: Do Read (nin,*,Iostat=ieof) n If (ieof<0) Exit loop Allocate (work(3*n+100),x(0:n+1),xx(0:n-1)) Read (nin,*) x(0:n-1) xx(0:n-1) = x(0:n-1) ! ifail: behaviour on error exit ! =0 for hard exit, =1 for quiet-soft, =-1 for noisy-soft ifail = 0 Call c06paf('F',x,n,work,ifail) Write (nout,*) Write (nout,*) 'Components of discrete Fourier transform' Write (nout,*) Write (nout,*) ' Real Imag' Write (nout,*) Write (nout,99999)(j,x(2*j),x(2*j+1),j=0,n/2) Do j = n/2 + 1, n - 1 nj = n - j Write (nout,99999) j, x(2*nj), -x(2*nj+1) End Do Call c06paf('B',x,n,work,ifail) Write (nout,*) Write (nout,*) 'Original sequence as restored by inverse transform' Write (nout,*) Write (nout,*) ' Original Restored' Write (nout,*) Write (nout,99999)(j,xx(j),x(j),j=0,n-1) Deallocate (work,x,xx) End Do loop 99999 Format (1X,I5,2F10.5) End Program c06pafe