[1] | 1 | !CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC |
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| 2 | ! |
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| 3 | ! FFTPACK 5.0 |
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| 4 | ! |
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| 5 | ! Authors: Paul N. Swarztrauber and Richard A. Valent |
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| 6 | ! |
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| 7 | ! $Id: r1fgkb.f,v 1.2 2004/06/15 21:29:20 rodney Exp $ |
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| 8 | ! |
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| 9 | !CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC |
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| 10 | |
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| 11 | SUBROUTINE R1FGKB (IDO,IP,L1,IDL1,CC,C1,C2,IN1, & |
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| 12 | & CH,CH2,IN2,WA) |
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| 13 | REAL CH(IN2,IDO,L1,IP) ,CC(IN1,IDO,IP,L1) , & |
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| 14 | & C1(IN1,IDO,L1,IP) ,C2(IN1,IDL1,IP), & |
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| 15 | & CH2(IN2,IDL1,IP) ,WA(IDO) |
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| 16 | ! |
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| 17 | TPI=2.*4.*ATAN(1.0) |
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| 18 | ARG = TPI/FLOAT(IP) |
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| 19 | DCP = COS(ARG) |
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| 20 | DSP = SIN(ARG) |
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| 21 | IDP2 = IDO+2 |
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| 22 | NBD = (IDO-1)/2 |
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| 23 | IPP2 = IP+2 |
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| 24 | IPPH = (IP+1)/2 |
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| 25 | IF (IDO .LT. L1) GO TO 103 |
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| 26 | DO 102 K=1,L1 |
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| 27 | DO 101 I=1,IDO |
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| 28 | CH(1,I,K,1) = CC(1,I,1,K) |
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| 29 | 101 CONTINUE |
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| 30 | 102 END DO |
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| 31 | GO TO 106 |
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| 32 | 103 DO 105 I=1,IDO |
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| 33 | DO 104 K=1,L1 |
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| 34 | CH(1,I,K,1) = CC(1,I,1,K) |
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| 35 | 104 CONTINUE |
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| 36 | 105 END DO |
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| 37 | 106 DO 108 J=2,IPPH |
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| 38 | JC = IPP2-J |
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| 39 | J2 = J+J |
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| 40 | DO 107 K=1,L1 |
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| 41 | CH(1,1,K,J) = CC(1,IDO,J2-2,K)+CC(1,IDO,J2-2,K) |
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| 42 | CH(1,1,K,JC) = CC(1,1,J2-1,K)+CC(1,1,J2-1,K) |
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| 43 | 1007 CONTINUE |
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| 44 | 107 CONTINUE |
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| 45 | 108 END DO |
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| 46 | IF (IDO .EQ. 1) GO TO 116 |
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| 47 | IF (NBD .LT. L1) GO TO 112 |
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| 48 | DO 111 J=2,IPPH |
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| 49 | JC = IPP2-J |
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| 50 | DO 110 K=1,L1 |
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| 51 | DO 109 I=3,IDO,2 |
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| 52 | IC = IDP2-I |
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| 53 | CH(1,I-1,K,J) = CC(1,I-1,2*J-1,K)+CC(1,IC-1,2*J-2,K) |
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| 54 | CH(1,I-1,K,JC) = CC(1,I-1,2*J-1,K)-CC(1,IC-1,2*J-2,K) |
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| 55 | CH(1,I,K,J) = CC(1,I,2*J-1,K)-CC(1,IC,2*J-2,K) |
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| 56 | CH(1,I,K,JC) = CC(1,I,2*J-1,K)+CC(1,IC,2*J-2,K) |
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| 57 | 109 CONTINUE |
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| 58 | 110 CONTINUE |
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| 59 | 111 END DO |
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| 60 | GO TO 116 |
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| 61 | 112 DO 115 J=2,IPPH |
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| 62 | JC = IPP2-J |
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| 63 | DO 114 I=3,IDO,2 |
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| 64 | IC = IDP2-I |
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| 65 | DO 113 K=1,L1 |
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| 66 | CH(1,I-1,K,J) = CC(1,I-1,2*J-1,K)+CC(1,IC-1,2*J-2,K) |
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| 67 | CH(1,I-1,K,JC) = CC(1,I-1,2*J-1,K)-CC(1,IC-1,2*J-2,K) |
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| 68 | CH(1,I,K,J) = CC(1,I,2*J-1,K)-CC(1,IC,2*J-2,K) |
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| 69 | CH(1,I,K,JC) = CC(1,I,2*J-1,K)+CC(1,IC,2*J-2,K) |
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| 70 | 113 CONTINUE |
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| 71 | 114 CONTINUE |
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| 72 | 115 END DO |
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| 73 | 116 AR1 = 1. |
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| 74 | AI1 = 0. |
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| 75 | DO 120 L=2,IPPH |
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| 76 | LC = IPP2-L |
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| 77 | AR1H = DCP*AR1-DSP*AI1 |
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| 78 | AI1 = DCP*AI1+DSP*AR1 |
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| 79 | AR1 = AR1H |
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| 80 | DO 117 IK=1,IDL1 |
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| 81 | C2(1,IK,L) = CH2(1,IK,1)+AR1*CH2(1,IK,2) |
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| 82 | C2(1,IK,LC) = AI1*CH2(1,IK,IP) |
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| 83 | 117 CONTINUE |
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| 84 | DC2 = AR1 |
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| 85 | DS2 = AI1 |
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| 86 | AR2 = AR1 |
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| 87 | AI2 = AI1 |
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| 88 | DO 119 J=3,IPPH |
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| 89 | JC = IPP2-J |
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| 90 | AR2H = DC2*AR2-DS2*AI2 |
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| 91 | AI2 = DC2*AI2+DS2*AR2 |
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| 92 | AR2 = AR2H |
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| 93 | DO 118 IK=1,IDL1 |
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| 94 | C2(1,IK,L) = C2(1,IK,L)+AR2*CH2(1,IK,J) |
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| 95 | C2(1,IK,LC) = C2(1,IK,LC)+AI2*CH2(1,IK,JC) |
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| 96 | 118 CONTINUE |
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| 97 | 119 CONTINUE |
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| 98 | 120 END DO |
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| 99 | DO 122 J=2,IPPH |
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| 100 | DO 121 IK=1,IDL1 |
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| 101 | CH2(1,IK,1) = CH2(1,IK,1)+CH2(1,IK,J) |
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| 102 | 121 CONTINUE |
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| 103 | 122 END DO |
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| 104 | DO 124 J=2,IPPH |
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| 105 | JC = IPP2-J |
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| 106 | DO 123 K=1,L1 |
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| 107 | CH(1,1,K,J) = C1(1,1,K,J)-C1(1,1,K,JC) |
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| 108 | CH(1,1,K,JC) = C1(1,1,K,J)+C1(1,1,K,JC) |
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| 109 | 123 CONTINUE |
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| 110 | 124 END DO |
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| 111 | IF (IDO .EQ. 1) GO TO 132 |
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| 112 | IF (NBD .LT. L1) GO TO 128 |
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| 113 | DO 127 J=2,IPPH |
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| 114 | JC = IPP2-J |
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| 115 | DO 126 K=1,L1 |
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| 116 | DO 125 I=3,IDO,2 |
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| 117 | CH(1,I-1,K,J) = C1(1,I-1,K,J)-C1(1,I,K,JC) |
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| 118 | CH(1,I-1,K,JC) = C1(1,I-1,K,J)+C1(1,I,K,JC) |
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| 119 | CH(1,I,K,J) = C1(1,I,K,J)+C1(1,I-1,K,JC) |
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| 120 | CH(1,I,K,JC) = C1(1,I,K,J)-C1(1,I-1,K,JC) |
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| 121 | 125 CONTINUE |
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| 122 | 126 CONTINUE |
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| 123 | 127 END DO |
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| 124 | GO TO 132 |
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| 125 | 128 DO 131 J=2,IPPH |
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| 126 | JC = IPP2-J |
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| 127 | DO 130 I=3,IDO,2 |
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| 128 | DO 129 K=1,L1 |
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| 129 | CH(1,I-1,K,J) = C1(1,I-1,K,J)-C1(1,I,K,JC) |
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| 130 | CH(1,I-1,K,JC) = C1(1,I-1,K,J)+C1(1,I,K,JC) |
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| 131 | CH(1,I,K,J) = C1(1,I,K,J)+C1(1,I-1,K,JC) |
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| 132 | CH(1,I,K,JC) = C1(1,I,K,J)-C1(1,I-1,K,JC) |
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| 133 | 129 CONTINUE |
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| 134 | 130 CONTINUE |
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| 135 | 131 END DO |
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| 136 | 132 CONTINUE |
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| 137 | IF (IDO .EQ. 1) RETURN |
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| 138 | DO 133 IK=1,IDL1 |
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| 139 | C2(1,IK,1) = CH2(1,IK,1) |
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| 140 | 133 END DO |
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| 141 | DO 135 J=2,IP |
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| 142 | DO 134 K=1,L1 |
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| 143 | C1(1,1,K,J) = CH(1,1,K,J) |
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| 144 | 134 CONTINUE |
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| 145 | 135 END DO |
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| 146 | IF (NBD .GT. L1) GO TO 139 |
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| 147 | IS = -IDO |
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| 148 | DO 138 J=2,IP |
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| 149 | IS = IS+IDO |
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| 150 | IDIJ = IS |
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| 151 | DO 137 I=3,IDO,2 |
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| 152 | IDIJ = IDIJ+2 |
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| 153 | DO 136 K=1,L1 |
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| 154 | C1(1,I-1,K,J) = WA(IDIJ-1)*CH(1,I-1,K,J)-WA(IDIJ)* & |
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| 155 | & CH(1,I,K,J) |
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| 156 | C1(1,I,K,J) = WA(IDIJ-1)*CH(1,I,K,J)+WA(IDIJ)* & |
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| 157 | & CH(1,I-1,K,J) |
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| 158 | 136 CONTINUE |
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| 159 | 137 CONTINUE |
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| 160 | 138 END DO |
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| 161 | GO TO 143 |
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| 162 | 139 IS = -IDO |
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| 163 | DO 142 J=2,IP |
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| 164 | IS = IS+IDO |
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| 165 | DO 141 K=1,L1 |
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| 166 | IDIJ = IS |
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| 167 | DO 140 I=3,IDO,2 |
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| 168 | IDIJ = IDIJ+2 |
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| 169 | C1(1,I-1,K,J) = WA(IDIJ-1)*CH(1,I-1,K,J)-WA(IDIJ)* & |
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| 170 | & CH(1,I,K,J) |
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| 171 | C1(1,I,K,J) = WA(IDIJ-1)*CH(1,I,K,J)+WA(IDIJ)* & |
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| 172 | & CH(1,I-1,K,J) |
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| 173 | 140 CONTINUE |
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| 174 | 141 CONTINUE |
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| 175 | 142 END DO |
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| 176 | 143 RETURN |
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| 177 | END |
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