# clargv.f man page

clargv.f —

## Synopsis

### Functions/Subroutines

subroutineclargv(N, X, INCX, Y, INCY, C, INCC)CLARGVgenerates 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
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.

**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.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

clargv(3) is an alias of clargv.f(3).