*DECK PASSB3 SUBROUTINE PASSB3 (IDO, L1, CC, CH, WA1, WA2) C***BEGIN PROLOGUE PASSB3 C***SUBSIDIARY C***PURPOSE Calculate the fast Fourier transform of subvectors of C length three. C***LIBRARY SLATEC (FFTPACK) C***TYPE SINGLE PRECISION (PASSB3-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 variable TAUI by using C FORTRAN intrinsic function SQRT instead of a DATA C statement. 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 PASSB3