Provided by: liblapack-doc_3.12.1-2_all 
NAME
largv - largv: generate vector of plane rotations
SYNOPSIS
Functions
subroutine clargv (n, x, incx, y, incy, c, incc)
CLARGV generates a vector of plane rotations with real cosines and complex sines.
subroutine dlargv (n, x, incx, y, incy, c, incc)
DLARGV generates a vector of plane rotations with real cosines and real sines.
subroutine slargv (n, x, incx, y, incy, c, incc)
SLARGV generates a vector of plane rotations with real cosines and real sines.
subroutine zlargv (n, x, incx, y, incy, c, incc)
ZLARGV generates a vector of plane rotations with real cosines and complex sines.
Detailed Description
Function Documentation
subroutine clargv (integer n, complex, dimension( * ) x, integer incx, complex, dimension( * ) y, integer
incy, real, dimension( * ) c, integer incc)
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
The number of plane rotations to be generated.
X
X is COMPLEX 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 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 REAL array, dimension (1+(N-1)*INCC)
The cosines of the plane rotations.
INCC
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.
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.
subroutine dlargv (integer n, double precision, dimension( * ) x, integer incx, double precision, dimension(
* ) y, integer incy, double precision, dimension( * ) c, integer incc)
DLARGV generates a vector of plane rotations with real cosines and real sines.
Purpose:
DLARGV generates a vector of real plane rotations, determined by
elements of the real vectors x and y. For i = 1,2,...,n
( c(i) s(i) ) ( x(i) ) = ( a(i) )
( -s(i) c(i) ) ( y(i) ) = ( 0 )
Parameters
N
N is INTEGER
The number of plane rotations to be generated.
X
X is DOUBLE PRECISION array,
dimension (1+(N-1)*INCX)
On entry, the vector x.
On exit, x(i) is overwritten by a(i), for i = 1,...,n.
INCX
INCX is INTEGER
The increment between elements of X. INCX > 0.
Y
Y is DOUBLE PRECISION 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.
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
subroutine slargv (integer n, real, dimension( * ) x, integer incx, real, dimension( * ) y, integer incy,
real, dimension( * ) c, integer incc)
SLARGV generates a vector of plane rotations with real cosines and real sines.
Purpose:
SLARGV generates a vector of real plane rotations, determined by
elements of the real vectors x and y. For i = 1,2,...,n
( c(i) s(i) ) ( x(i) ) = ( a(i) )
( -s(i) c(i) ) ( y(i) ) = ( 0 )
Parameters
N
N is INTEGER
The number of plane rotations to be generated.
X
X is REAL array,
dimension (1+(N-1)*INCX)
On entry, the vector x.
On exit, x(i) is overwritten by a(i), for i = 1,...,n.
INCX
INCX is INTEGER
The increment between elements of X. INCX > 0.
Y
Y is REAL 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 REAL array, dimension (1+(N-1)*INCC)
The cosines of the plane rotations.
INCC
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.
subroutine zlargv (integer n, complex*16, dimension( * ) x, integer incx, complex*16, dimension( * ) y,
integer incy, double precision, dimension( * ) c, integer incc)
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.
Parameters
N
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.
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
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.
Author
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Version 3.12.0 Tue Jan 28 2025 00:54:31 largv(3)