| 1 | !CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC |
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| 2 | ! |
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| 3 | ! FFTPACK 5.0 |
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| 4 | ! Copyright (C) 1995-2004, Scientific Computing Division, |
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| 5 | ! University Corporation for Atmospheric Research |
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| 6 | ! Licensed under the GNU General Public License (GPL) |
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| 7 | ! |
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| 8 | ! Authors: Paul N. Swarztrauber and Richard A. Valent |
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| 9 | ! |
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| 10 | ! $Id: cfft2b.f,v 1.2 2004/06/15 21:08:32 rodney Exp $ |
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| 11 | ! |
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| 12 | !CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC |
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| 13 | |
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| 14 | SUBROUTINE CFFT2B (LDIM, L, M, C, WSAVE, LENSAV, & |
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| 15 | & WORK, LENWRK, IER) |
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| 16 | INTEGER L, M, LDIM, LENSAV, LENWRK, IER |
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| 17 | COMPLEX C(LDIM,M) |
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| 18 | REAL WSAVE(LENSAV), WORK(LENWRK) |
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| 19 | ! |
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| 20 | ! Initialize error return |
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| 21 | ! |
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| 22 | IER = 0 |
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| 23 | ! |
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| 24 | IF (L .GT. LDIM) THEN |
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| 25 | IER = 5 |
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| 26 | CALL XERFFT ('CFFT2B', -2) |
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| 27 | GO TO 100 |
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| 28 | ELSEIF (LENSAV .LT. 2*L + INT(LOG(REAL(L))) + & |
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| 29 | & 2*M + INT(LOG(REAL(M))) +8) THEN |
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| 30 | IER = 2 |
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| 31 | CALL XERFFT ('CFFT2B', 6) |
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| 32 | GO TO 100 |
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| 33 | ELSEIF (LENWRK .LT. 2*L*M) THEN |
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| 34 | IER = 3 |
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| 35 | CALL XERFFT ('CFFT2B', 8) |
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| 36 | GO TO 100 |
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| 37 | ENDIF |
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| 38 | ! |
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| 39 | ! Transform X lines of C array |
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| 40 | IW = 2*L+INT(LOG(REAL(L))*LOG(2.)) + 3 |
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| 41 | CALL CFFTMB(L, 1, M, LDIM, C, (L-1) + LDIM*(M-1) +1, & |
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| 42 | & WSAVE(IW), 2*M + INT(LOG(REAL(M))) + 4, & |
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| 43 | & WORK, 2*L*M, IER1) |
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| 44 | IF (IER1 .NE. 0) THEN |
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| 45 | IER = 20 |
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| 46 | CALL XERFFT ('CFFT2B',-5) |
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| 47 | GO TO 100 |
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| 48 | ENDIF |
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| 49 | ! |
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| 50 | ! Transform Y lines of C array |
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| 51 | IW = 1 |
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| 52 | CALL CFFTMB (M, LDIM, L, 1, C, (M-1)*LDIM + L, & |
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| 53 | & WSAVE(IW), 2*L + INT(LOG(REAL(L))) + 4, & |
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| 54 | & WORK, 2*M*L, IER1) |
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| 55 | IF (IER1 .NE. 0) THEN |
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| 56 | IER = 20 |
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| 57 | CALL XERFFT ('CFFT2B',-5) |
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| 58 | ENDIF |
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| 59 | ! |
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| 60 | 100 CONTINUE |
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| 61 | RETURN |
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| 62 | END |
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