subroutine zlargv (N, X, INCX, Y, INCY, C, INCC)
subroutine zlargv (integerN, complex*16, dimension( * )X, integerINCX, complex*16, dimension( * )Y, integerINCY, double precision, dimension( * )C, integerINCC)ZLARGV generates a vector of plane rotations with real cosines and complex sines. Purpose:
ZLARGV generates a vector of complex plane rotations with real cosines, determined by elements of the complex vectors x and y. For i = 1,2,...,n ( c(i) s(i) ) ( x(i) ) = ( r(i) ) ( -conjg(s(i)) c(i) ) ( y(i) ) = ( 0 ) where c(i)**2 + ABS(s(i))**2 = 1 The following conventions are used (these are the same as in ZLARTG, but differ from the BLAS1 routine ZROTG): If y(i)=0, then c(i)=1 and s(i)=0. If x(i)=0, then c(i)=0 and s(i) is chosen so that r(i) is real.
N is INTEGER The number of plane rotations to be generated.X
X is COMPLEX*16 array, dimension (1+(N-1)*INCX) On entry, the vector x. On exit, x(i) is overwritten by r(i), for i = 1,...,n.INCX
INCX is INTEGER The increment between elements of X. INCX > 0.Y
Y is COMPLEX*16 array, dimension (1+(N-1)*INCY) On entry, the vector y. On exit, the sines of the plane rotations.INCY
INCY is INTEGER The increment between elements of Y. INCY > 0.C
C is DOUBLE PRECISION array, dimension (1+(N-1)*INCC) The cosines of the plane rotations.INCC
INCC is INTEGER The increment between elements of C. INCC > 0.
Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd.Date:
September 2012Further Details:
6-6-96 - Modified with a new algorithm by W. Kahan and J. Demmel This version has a few statements commented out for thread safety (machine parameters are computed on each entry). 10 feb 03, SJH.