Program c06frfe ! C06FRF Example Program Text ! Mark 24 Release. NAG Copyright 2012. ! .. Use Statements .. Use nag_library, Only: c06frf, c06gcf, nag_wp ! .. Implicit None Statement .. Implicit None ! .. Parameters .. Integer, Parameter :: nin = 5, nout = 6 Character (7), Parameter :: init_first = 'Initial' Character (10), Parameter :: init_repeat = 'Subsequent' ! .. Local Scalars .. Integer :: i, ieof, ifail, lwork, m, mn, n, n2 ! .. Local Arrays .. Real (Kind=nag_wp), Allocatable :: trig(:), work(:), x(:,:), y(:,:) ! .. Executable Statements .. Write (nout,*) 'C06FRF Example Program Results' ! Skip heading in data file Read (nin,*) loop: Do Read (nin,*,Iostat=ieof) m, n mn = m*n n2 = 2*n lwork = 2*mn If (ieof<0) Exit loop Allocate (trig(n2),x(m,n),y(m,n),work(lwork)) Do i = 1, m Read (nin,*) x(i,1:n) Read (nin,*) y(i,1:n) End Do Write (nout,*) Write (nout,*) 'Original data values' Do i = 1, m Write (nout,*) Write (nout,99999) 'Real ', x(i,1:n) Write (nout,99999) 'Imag ', y(i,1:n) End Do ! ifail: behaviour on error exit ! =0 for hard exit, =1 for quiet-soft, =-1 for noisy-soft ifail = 0 Call c06frf(m,n,x,y,init_first,trig,work,ifail) Write (nout,*) Write (nout,*) 'Discrete Fourier transforms' Do i = 1, m Write (nout,*) Write (nout,99999) 'Real ', x(i,1:n) Write (nout,99999) 'Imag ', y(i,1:n) End Do Call c06gcf(y,mn,ifail) ifail = 0 Call c06frf(m,n,x,y,init_repeat,trig,work,ifail) Call c06gcf(y,mn,ifail) Write (nout,*) Write (nout,*) 'Original data as restored by inverse transform' Do i = 1, m Write (nout,*) Write (nout,99999) 'Real ', x(i,1:n) Write (nout,99999) 'Imag ', y(i,1:n) End Do Deallocate (trig,x,y,work) End Do loop 99999 Format (1X,A,6F10.4) End Program c06frfe