*DECK PASSB5 SUBROUTINE PASSB5 (IDO, L1, CC, CH, WA1, WA2, WA3, WA4) C***BEGIN PROLOGUE PASSB5 C***SUBSIDIARY C***PURPOSE Calculate the fast Fourier transform of subvectors of C length five. C***LIBRARY SLATEC (FFTPACK) C***TYPE SINGLE PRECISION (PASSB5-S) C***AUTHOR Swarztrauber, P. N., (NCAR) C***ROUTINES CALLED (NONE) C***REVISION HISTORY (YYMMDD) C 790601 DATE WRITTEN C 830401 Modified to use SLATEC library source file format. C 860115 Modified by Ron Boisvert to adhere to Fortran 77 by C (a) changing dummy array size declarations (1) to (*), C (b) changing definition of variables PI, TI11, TI12, C TR11, TR12 by using FORTRAN intrinsic functions ATAN C and SIN instead of DATA statements. C 881128 Modified by Dick Valent to meet prologue standards. C 890831 Modified array declarations. (WRB) C 891214 Prologue converted to Version 4.0 format. (BAB) C 900402 Added TYPE section. (WRB) C***END PROLOGUE PASSB5 DIMENSION CC(IDO,5,*), CH(IDO,L1,5), WA1(*), WA2(*), WA3(*), + WA4(*) C***FIRST EXECUTABLE STATEMENT PASSB5 PI = 4.*ATAN(1.) TR11 = SIN(.1*PI) TI11 = SIN(.4*PI) TR12 = -SIN(.3*PI) TI12 = SIN(.2*PI) IF (IDO .NE. 2) GO TO 102 DO 101 K=1,L1 TI5 = CC(2,2,K)-CC(2,5,K) TI2 = CC(2,2,K)+CC(2,5,K) TI4 = CC(2,3,K)-CC(2,4,K) TI3 = CC(2,3,K)+CC(2,4,K) TR5 = CC(1,2,K)-CC(1,5,K) TR2 = CC(1,2,K)+CC(1,5,K) TR4 = CC(1,3,K)-CC(1,4,K) TR3 = CC(1,3,K)+CC(1,4,K) CH(1,K,1) = CC(1,1,K)+TR2+TR3 CH(2,K,1) = CC(2,1,K)+TI2+TI3 CR2 = CC(1,1,K)+TR11*TR2+TR12*TR3 CI2 = CC(2,1,K)+TR11*TI2+TR12*TI3 CR3 = CC(1,1,K)+TR12*TR2+TR11*TR3 CI3 = CC(2,1,K)+TR12*TI2+TR11*TI3 CR5 = TI11*TR5+TI12*TR4 CI5 = TI11*TI5+TI12*TI4 CR4 = TI12*TR5-TI11*TR4 CI4 = TI12*TI5-TI11*TI4 CH(1,K,2) = CR2-CI5 CH(1,K,5) = CR2+CI5 CH(2,K,2) = CI2+CR5 CH(2,K,3) = CI3+CR4 CH(1,K,3) = CR3-CI4 CH(1,K,4) = CR3+CI4 CH(2,K,4) = CI3-CR4 CH(2,K,5) = CI2-CR5 101 CONTINUE RETURN 102 IF(IDO/2.LT.L1) GO TO 105 DO 104 K=1,L1 CDIR$ IVDEP DO 103 I=2,IDO,2 TI5 = CC(I,2,K)-CC(I,5,K) TI2 = CC(I,2,K)+CC(I,5,K) TI4 = CC(I,3,K)-CC(I,4,K) TI3 = CC(I,3,K)+CC(I,4,K) TR5 = CC(I-1,2,K)-CC(I-1,5,K) TR2 = CC(I-1,2,K)+CC(I-1,5,K) TR4 = CC(I-1,3,K)-CC(I-1,4,K) TR3 = CC(I-1,3,K)+CC(I-1,4,K) CH(I-1,K,1) = CC(I-1,1,K)+TR2+TR3 CH(I,K,1) = CC(I,1,K)+TI2+TI3 CR2 = CC(I-1,1,K)+TR11*TR2+TR12*TR3 CI2 = CC(I,1,K)+TR11*TI2+TR12*TI3 CR3 = CC(I-1,1,K)+TR12*TR2+TR11*TR3 CI3 = CC(I,1,K)+TR12*TI2+TR11*TI3 CR5 = TI11*TR5+TI12*TR4 CI5 = TI11*TI5+TI12*TI4 CR4 = TI12*TR5-TI11*TR4 CI4 = TI12*TI5-TI11*TI4 DR3 = CR3-CI4 DR4 = CR3+CI4 DI3 = CI3+CR4 DI4 = CI3-CR4 DR5 = CR2+CI5 DR2 = CR2-CI5 DI5 = CI2-CR5 DI2 = CI2+CR5 CH(I-1,K,2) = WA1(I-1)*DR2-WA1(I)*DI2 CH(I,K,2) = WA1(I-1)*DI2+WA1(I)*DR2 CH(I-1,K,3) = WA2(I-1)*DR3-WA2(I)*DI3 CH(I,K,3) = WA2(I-1)*DI3+WA2(I)*DR3 CH(I-1,K,4) = WA3(I-1)*DR4-WA3(I)*DI4 CH(I,K,4) = WA3(I-1)*DI4+WA3(I)*DR4 CH(I-1,K,5) = WA4(I-1)*DR5-WA4(I)*DI5 CH(I,K,5) = WA4(I-1)*DI5+WA4(I)*DR5 103 CONTINUE 104 CONTINUE RETURN 105 DO 107 I=2,IDO,2 CDIR$ IVDEP DO 106 K=1,L1 TI5 = CC(I,2,K)-CC(I,5,K) TI2 = CC(I,2,K)+CC(I,5,K) TI4 = CC(I,3,K)-CC(I,4,K) TI3 = CC(I,3,K)+CC(I,4,K) TR5 = CC(I-1,2,K)-CC(I-1,5,K) TR2 = CC(I-1,2,K)+CC(I-1,5,K) TR4 = CC(I-1,3,K)-CC(I-1,4,K) TR3 = CC(I-1,3,K)+CC(I-1,4,K) CH(I-1,K,1) = CC(I-1,1,K)+TR2+TR3 CH(I,K,1) = CC(I,1,K)+TI2+TI3 CR2 = CC(I-1,1,K)+TR11*TR2+TR12*TR3 CI2 = CC(I,1,K)+TR11*TI2+TR12*TI3 CR3 = CC(I-1,1,K)+TR12*TR2+TR11*TR3 CI3 = CC(I,1,K)+TR12*TI2+TR11*TI3 CR5 = TI11*TR5+TI12*TR4 CI5 = TI11*TI5+TI12*TI4 CR4 = TI12*TR5-TI11*TR4 CI4 = TI12*TI5-TI11*TI4 DR3 = CR3-CI4 DR4 = CR3+CI4 DI3 = CI3+CR4 DI4 = CI3-CR4 DR5 = CR2+CI5 DR2 = CR2-CI5 DI5 = CI2-CR5 DI2 = CI2+CR5 CH(I-1,K,2) = WA1(I-1)*DR2-WA1(I)*DI2 CH(I,K,2) = WA1(I-1)*DI2+WA1(I)*DR2 CH(I-1,K,3) = WA2(I-1)*DR3-WA2(I)*DI3 CH(I,K,3) = WA2(I-1)*DI3+WA2(I)*DR3 CH(I-1,K,4) = WA3(I-1)*DR4-WA3(I)*DI4 CH(I,K,4) = WA3(I-1)*DI4+WA3(I)*DR4 CH(I-1,K,5) = WA4(I-1)*DR5-WA4(I)*DI5 CH(I,K,5) = WA4(I-1)*DI5+WA4(I)*DR5 106 CONTINUE 107 CONTINUE RETURN END