| 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: mcsqf1.f,v 1.2 2004/06/15 21:29:19 rodney Exp $ |
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| 11 | ! |
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| 12 | !CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC |
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| 13 | |
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| 14 | SUBROUTINE MCSQF1 (LOT,JUMP,N,INC,X,WSAVE,WORK,IER) |
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| 15 | DIMENSION X(INC,*) ,WSAVE(*) ,WORK(LOT,*) |
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| 16 | IER = 0 |
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| 17 | LJ = (LOT-1)*JUMP+1 |
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| 18 | NS2 = (N+1)/2 |
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| 19 | NP2 = N+2 |
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| 20 | DO 101 K=2,NS2 |
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| 21 | KC = NP2-K |
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| 22 | M1 = 0 |
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| 23 | DO 201 M=1,LJ,JUMP |
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| 24 | M1 = M1 + 1 |
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| 25 | WORK(M1,K) = X(M,K)+X(M,KC) |
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| 26 | WORK(M1,KC) = X(M,K)-X(M,KC) |
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| 27 | 201 CONTINUE |
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| 28 | 101 END DO |
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| 29 | MODN = MOD(N,2) |
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| 30 | IF (MODN .NE. 0) GO TO 301 |
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| 31 | M1 = 0 |
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| 32 | DO 202 M=1,LJ,JUMP |
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| 33 | M1 = M1 + 1 |
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| 34 | WORK(M1,NS2+1) = X(M,NS2+1)+X(M,NS2+1) |
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| 35 | 202 CONTINUE |
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| 36 | 301 DO 102 K=2,NS2 |
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| 37 | KC = NP2-K |
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| 38 | M1 = 0 |
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| 39 | DO 302 M=1,LJ,JUMP |
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| 40 | M1 = M1 + 1 |
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| 41 | X(M,K) = WSAVE(K-1)*WORK(M1,KC)+WSAVE(KC-1)*WORK(M1,K) |
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| 42 | X(M,KC) = WSAVE(K-1)*WORK(M1,K) -WSAVE(KC-1)*WORK(M1,KC) |
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| 43 | 302 CONTINUE |
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| 44 | 102 END DO |
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| 45 | IF (MODN .NE. 0) GO TO 303 |
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| 46 | M1 = 0 |
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| 47 | DO 304 M=1,LJ,JUMP |
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| 48 | M1 = M1 + 1 |
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| 49 | X(M,NS2+1) = WSAVE(NS2)*WORK(M1,NS2+1) |
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| 50 | 304 END DO |
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| 51 | 303 CONTINUE |
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| 52 | LENX = (LOT-1)*JUMP + INC*(N-1) + 1 |
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| 53 | LNSV = N + INT(LOG(REAL(N))) + 4 |
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| 54 | LNWK = LOT*N |
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| 55 | ! |
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| 56 | CALL RFFTMF(LOT,JUMP,N,INC,X,LENX,WSAVE(N+1),LNSV,WORK,LNWK,IER1) |
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| 57 | IF (IER1 .NE. 0) THEN |
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| 58 | IER = 20 |
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| 59 | CALL XERFFT ('MCSQF1',-5) |
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| 60 | GO TO 400 |
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| 61 | ENDIF |
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| 62 | ! |
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| 63 | DO 103 I=3,N,2 |
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| 64 | DO 203 M=1,LJ,JUMP |
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| 65 | XIM1 = .5*(X(M,I-1)+X(M,I)) |
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| 66 | X(M,I) = .5*(X(M,I-1)-X(M,I)) |
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| 67 | X(M,I-1) = XIM1 |
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| 68 | 203 CONTINUE |
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| 69 | 103 END DO |
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| 70 | 400 CONTINUE |
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| 71 | RETURN |
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| 72 | END |
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