SROT(3)

SYNOPSIS
SUBROUTINE SROT (N, SX, INCX, SY, INCY, SC, SS)

NAME
srot - Apply a plane Givens rotation.

LIBRARY
SLATEC (BLAS)

CATEGORY
D1A8

TYPE
SINGLE PRECISION (SROT-S, DROT-D, CSROT-C)

KEYWORDS
BLAS, GIVENS ROTATION, GIVENS TRANSFORMATION, LINEAR ALGEBRA, PLANE ROTATION, VECTOR

AUTHOR
Lawson, C. L., (JPL) Hanson, R. J., (SNLA) Kincaid, D. R., (U. of Texas) Krogh, F. T., (JPL)

DESCRIPTION
B L A S Subprogram Description of Parameters --Input-- N number of elements in input vector(s) SX single precision vector with N elements INCX storage spacing between elements of SX SY single precision vector with N elements INCY storage spacing between elements of SY SC element of rotation matrix SS element of rotation matrix --Output-- SX rotated vector SX (unchanged if N .LE. 0) SY rotated vector SY (unchanged if N .LE. 0) Multiply the 2 x 2 matrix ( SC SS) times the 2 x N matrix (SX**T) (-SS SC) (SY**T) where **T indicates transpose. The elements of SX are in SX(LX+I*INCX), I = 0 to N-1, where LX = 1 if INCX .GE. 0, else LX = 1+(1-N)*INCX, and similarly for SY using LY and INCY.

REFERENCES
C. L. Lawson, R. J. Hanson, D. R. Kincaid and F. T. Krogh, Basic linear algebra subprograms for Fortran usage, Algorithm No. 539, Transactions on Mathematical Software 5, 3 (September 1979), pp. 308-323.

ROUTINES CALLED
(NONE)

REVISION HISTORY (YYMMDD)
791001 DATE WRITTEN
861211 REVISION DATE from Version 3.2
891214 Prologue converted to Version 4.0 format. (BAB)
920310 Corrected definition of LX in DESCRIPTION. (WRB)
920501 Reformatted the REFERENCES section. (WRB)