Note: this is a BLAS routine and is not in libslatec.a
*DECK CROTG
SUBROUTINE CROTG (CA, CB, C, S)
C***BEGIN PROLOGUE CROTG
C***PURPOSE Construct a Givens transformation.
C***LIBRARY SLATEC (BLAS)
C***CATEGORY D1B10
C***TYPE COMPLEX (SROTG-S, DROTG-D, CROTG-C)
C***KEYWORDS BLAS, GIVENS ROTATION, GIVENS TRANSFORMATION,
C LINEAR ALGEBRA, VECTOR
C***AUTHOR (UNKNOWN)
C***DESCRIPTION
C
C Complex Givens transformation
C
C Construct the Givens transformation
C
C (C S)
C G = ( ), C**2 + ABS(S)**2 =1,
C (-S C)
C
C which zeros the second entry of the complex 2-vector (CA,CB)**T
C
C The quantity CA/ABS(CA)*NORM(CA,CB) overwrites CA in storage.
C
C Input:
C CA (Complex)
C CB (Complex)
C
C Output:
C CA (Complex) CA/ABS(CA)*NORM(CA,CB)
C C (Real)
C S (Complex)
C
C***REFERENCES (NONE)
C***ROUTINES CALLED (NONE)
C***REVISION HISTORY (YYMMDD)
C 790101 DATE WRITTEN
C 890531 Changed all specific intrinsics to generic. (WRB)
C 890531 REVISION DATE from Version 3.2
C 891214 Prologue converted to Version 4.0 format. (BAB)
C***END PROLOGUE CROTG