csrot.f
SUBROUTINE CSROT (N, CX, INCX, CY, INCY, C, S)
C***BEGIN PROLOGUE CSROT
C***PURPOSE Apply a plane Givens rotation.
C***LIBRARY SLATEC (BLAS)
C***CATEGORY D1B10
C***TYPE COMPLEX (SROT-S, DROT-D, CSROT-C)
C***KEYWORDS BLAS, GIVENS ROTATION, GIVENS TRANSFORMATION,
C LINEAR ALGEBRA, PLANE ROTATION, VECTOR
C***AUTHOR Dongarra, J., (ANL)
C***DESCRIPTION
C
C CSROT applies the complex Givens rotation
C
C (X) ( C S)(X)
C (Y) = (-S C)(Y)
C
C N times where for I = 0,...,N-1
C
C X = CX(LX+I*INCX)
C Y = CY(LY+I*INCY),
C
C where LX = 1 if INCX .GE. 0, else LX = 1+(1-N)*INCX, and LY is
C defined in a similar way using INCY.
C
C Argument Description
C
C N (integer) number of elements in each vector
C
C CX (complex array) beginning of one vector
C
C INCX (integer) memory spacing of successive elements
C of vector CX
C
C CY (complex array) beginning of the other vector
C
C INCY (integer) memory spacing of successive elements
C of vector CY
C
C C (real) cosine term of the rotation
C
C S (real) sine term of the rotation.
C
C***REFERENCES J. J. Dongarra, J. R. Bunch, C. B. Moler, and G. W.
C Stewart, LINPACK Users' Guide, SIAM, 1979.
C***ROUTINES CALLED (NONE)
C***REVISION HISTORY (YYMMDD)
C 810223 DATE WRITTEN
C 890831 Modified array declarations. (WRB)
C 890831 REVISION DATE from Version 3.2
C 891214 Prologue converted to Version 4.0 format. (BAB)
C 920310 Corrected definition of LX in DESCRIPTION. (WRB)
C 920501 Reformatted the REFERENCES section. (WRB)
C***END PROLOGUE CSROT