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- c
- c SCFFT1D_ex.f
- c
- c This simple example illustrates the use of the FORTRAN
- c interface to the complib 1d FFT routines to perform a
- c circular shift.
- c
- c This program reads the number of samples N for the sequence,
- c and the offset.
- c
- c
- c Copyright 1995, Silicon Graphics, Inc.
- c ALL RIGHTS RESERVED
- c
- c UNPUBLISHED -- Rights reserved under the copyright laws of the United
- c States. Use of a copyright notice is precautionary only and does not
- c imply publication or disclosure.
- c
- c U.S. GOVERNMENT RESTRICTED RIGHTS LEGEND:
- c Use, duplication or disclosure by the Government is subject to restrictions
- c as set forth in FAR 52.227.19(c)(2) or subparagraph (c)(1)(ii) of the Rights
- c in Technical Data and Computer Software clause at DFARS 252.227-7013 and/or
- c in similar or successor clauses in the FAR, or the DOD or NASA FAR
- c Supplement. Contractor/manufacturer is Silicon Graphics, Inc.,
- c 2011 N. Shoreline Blvd. Mountain View, CA 94039-7311.
- c
- c THE CONTENT OF THIS WORK CONTAINS CONFIDENTIAL AND PROPRIETARY
- c INFORMATION OF SILICON GRAPHICS, INC. ANY DUPLICATION, MODIFICATION,
- c DISTRIBUTION, OR DISCLOSURE IN ANY FORM, IN WHOLE, OR IN PART, IS STRICTLY
- c PROHIBITED WITHOUT THE PRIOR EXPRESS WRITTEN PERMISSION OF SILICON
- c GRAPHICS, INC.
- c
- c
- c To build executable:
- c % f77 -o SCFFT1D_ex SCFFT1D_ex.f -lcomplib.sgimath
- c
- c Tu run executable:
- c % SCFFT1D_ex
- c
- c Input:
- c 7
- c 2
- c
- c Output:
- c Input Array of size 7 :
- c 0.00 1.00 2.00 3.00 4.00 5.00 6.00
- c Filter of size 7 :
- c 0.00 0.00 1.00 0.00 0.00 0.00 0.00
- c Scaled Inverse FFT of Array.Filter of size 7 :
- c 5.00 6.00 0.00 1.00 2.00 3.00 4.00
- c
- c
- c
-
- PROGRAM SCFFT1D_ex
- IMPLICIT NONE
- INTEGER i, N, SIZE, OFFSET
- PARAMETER ( SIZE = 8 )
- REAL ARRAY( 2*((SIZE+2)/2) ), FILTER( 2*((SIZE+2)/2) ),
- & COEF ( SIZE+15 )
-
-
- c
- c Read in number of samples N and OFFSET.
- c
- READ( 5,* ) N, OFFSET
-
- c
- c Generate smaples.
- c
- DO I = 1, N
- ARRAY ( I ) = REAL( I ) - 1.
- FILTER( I ) = 0.
- END DO
-
- FILTER( OFFSET+1 ) = 1.0
-
- c
- c Print out input samples.
- c
- WRITE( 6,'( A, I2, A )' ) "Input Array of size",N," :"
- WRITE( 6,'( 10F6.2 )' ) ( ARRAY( I ), I = 1, N )
- WRITE( 6,'( A,I2,A )' ) "Filter of size", N, " :"
- WRITE( 6,'( 10F6.2 )' ) ( FILTER( I ), I = 1, N )
-
- c
- c Calculate circular shift.
- c
- CALL SCFFT1DUI ( N, COEF )
- CALL SCFFT1DU ( -1, N, ARRAY, 1, COEF )
- CALL SCFFT1DU ( -1, N, FILTER, 1, COEF )
- CALL SPROD1DU ( N, ARRAY, 1, FILTER, 1 )
- CALL CSFFT1DU ( 1, N, ARRAY, 1, COEF )
- CALL SSCAL1D ( N, 1./REAL(N), ARRAY, 1 )
-
- c
- c Print out results.
- c
- WRITE( 6,'( A, I2, A )' )
- & "Scaled Inverse FFT of Array.Filter of size", N, " :"
- WRITE( 6,'( 10F6.2 )' ) ( ARRAY( I ), I = 1, N )
-
- STOP
- END
-