---
name: "clargv.f"
section: "3"
platform: "linux"
package: "lapack-doc"
version: "3.12.1-2"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/clargv.f"
---

# clargv.f(3)

## NAME

SRC/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 (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.
!>
```

Definition at line **121** of file **clargv.f**.

## Author

Generated automatically by Doxygen for LAPACK from the source code.