2 SUBROUTINE RADB2 (IDO, L1, CC, CH, WA1)
3 C***BEGIN PROLOGUE RADB2
5 C***PURPOSE Calculate the fast Fourier transform of subvectors of
7 C***LIBRARY SLATEC (FFTPACK)
8 C***TYPE SINGLE PRECISION (RADB2-S)
9 C***AUTHOR Swarztrauber, P. N., (NCAR)
10 C***ROUTINES CALLED (NONE)
11 C***REVISION HISTORY (YYMMDD)
13 C 830401 Modified to use SLATEC library source file format.
14 C 860115 Modified by Ron Boisvert to adhere to Fortran 77 by
15 C changing dummy array size declarations (1) to (*).
16 C 881128 Modified by Dick Valent to meet prologue standards.
17 C 890831 Modified array declarations. (WRB)
18 C 891214 Prologue converted to Version 4.0 format. (BAB)
19 C 900402 Added TYPE section. (WRB)
20 C***END PROLOGUE RADB2
21 DIMENSION CC(IDO,2,*), CH(IDO,L1,2), WA1(*)
22 C***FIRST EXECUTABLE STATEMENT RADB2
24 CH(1,K,1) = CC(1,1,K)+CC(IDO,2,K)
25 CH(1,K,2) = CC(1,1,K)-CC(IDO,2,K)
27 IF (IDO-2) 107,105,102
29 IF((IDO-1)/2.LT.L1) GO TO 108
34 CH(I-1,K,1) = CC(I-1,1,K)+CC(IC-1,2,K)
35 TR2 = CC(I-1,1,K)-CC(IC-1,2,K)
36 CH(I,K,1) = CC(I,1,K)-CC(IC,2,K)
37 TI2 = CC(I,1,K)+CC(IC,2,K)
38 CH(I-1,K,2) = WA1(I-2)*TR2-WA1(I-1)*TI2
39 CH(I,K,2) = WA1(I-2)*TI2+WA1(I-1)*TR2
47 CH(I-1,K,1) = CC(I-1,1,K)+CC(IC-1,2,K)
48 TR2 = CC(I-1,1,K)-CC(IC-1,2,K)
49 CH(I,K,1) = CC(I,1,K)-CC(IC,2,K)
50 TI2 = CC(I,1,K)+CC(IC,2,K)
51 CH(I-1,K,2) = WA1(I-2)*TR2-WA1(I-1)*TI2
52 CH(I,K,2) = WA1(I-2)*TI2+WA1(I-1)*TR2
55 111 IF (MOD(IDO,2) .EQ. 1) RETURN
57 CH(IDO,K,1) = CC(IDO,1,K)+CC(IDO,1,K)
58 CH(IDO,K,2) = -(CC(1,2,K)+CC(1,2,K))