clargv.f (3) Linux Manual Page
clargv.f –
Synopsis
Functions/Subroutines
subroutine clargv (N, X, INCX, Y, INCY, C, INCC)CLARGV generates a vector of plane rotations with real cosines and complex sines.
Function/Subroutine Documentation
subroutine clargv (integerN, complex, dimension( * )X, integerINCX, complex, dimension( * )Y, integerINCY, real, dimension( * )C, integerINCC)
CLARGV generates a vector of plane rotations with real cosines and complex sines. Purpose:
CLARGV 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 CLARTG,
but differ from the BLAS1 routine CROTG):
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.
Parameters:
- N
N is INTEGER
X
The number of plane rotations to be generated.X is COMPLEX array, dimension (1+(N-1)*INCX)
INCX
On entry, the vector x.
On exit, x(i) is overwritten by r(i), for i = 1,…,n.INCX is INTEGER
Y
The increment between elements of X. INCX > 0.Y is COMPLEX array, dimension (1+(N-1)*INCY)
INCY
On entry, the vector y.
On exit, the sines of the plane rotations.INCY is INTEGER
C
The increment between elements of Y. INCY > 0.C is REAL array, dimension (1+(N-1)*INCC)
INCC
The cosines of the plane rotations.INCC is INTEGER
The increment between elements of C. INCC > 0.
Author:
- Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
- September 2012
Further 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.
Definition at line 123 of file clargv.f.