---
name: "clar2v.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/clar2v.f"
---

# clar2v.f(3)

## NAME

SRC/clar2v.f

## SYNOPSIS

### Functions/Subroutines

subroutine **clar2v** (n, x, y, z, incx, c, s, incc)\
 **CLAR2V** applies a vector of plane rotations with real cosines and complex sines from both sides to a sequence of 2-by-2 symmetric/Hermitian matrices.

## Function/Subroutine Documentation

### subroutine clar2v (integer n, complex, dimension( \* ) x, complex, dimension( \* ) y, complex, dimension( \* ) z, integer incx, real, dimension( \* ) c, complex, dimension( \* ) s, integer incc)

**CLAR2V** applies a vector of plane rotations with real cosines and complex sines from both sides to a sequence of 2-by-2 symmetric/Hermitian matrices.

**Purpose:**

```
!>
!> CLAR2V applies a vector of complex plane rotations with real cosines
!> from both sides to a sequence of 2-by-2 complex Hermitian matrices,
!> defined by the elements of the vectors x, y and z. For i = 1,2,...,n
!>
!>    (       x(i)  z(i) ) :=
!>    ( conjg(z(i)) y(i) )
!>
!>      (  c(i) conjg(s(i)) ) (       x(i)  z(i) ) ( c(i) -conjg(s(i)) )
!>      ( -s(i)       c(i)  ) ( conjg(z(i)) y(i) ) ( s(i)        c(i)  )
!>
```

**Parameters**

*N*

```
!>          N is INTEGER
!>          The number of plane rotations to be applied.
!>
```

*X*

```
!>          X is COMPLEX array, dimension (1+(N-1)*INCX)
!>          The vector x; the elements of x are assumed to be real.
!>
```

*Y*

```
!>          Y is COMPLEX array, dimension (1+(N-1)*INCX)
!>          The vector y; the elements of y are assumed to be real.
!>
```

*Z*

```
!>          Z is COMPLEX array, dimension (1+(N-1)*INCX)
!>          The vector z.
!>
```

*INCX*

```
!>          INCX is INTEGER
!>          The increment between elements of X, Y and Z. INCX > 0.
!>
```

*C*

```
!>          C is REAL array, dimension (1+(N-1)*INCC)
!>          The cosines of the plane rotations.
!>
```

*S*

```
!>          S is COMPLEX array, dimension (1+(N-1)*INCC)
!>          The sines of the plane rotations.
!>
```

*INCC*

```
!>          INCC is INTEGER
!>          The increment between elements of C and S. INCC > 0.
!>
```

**Author**

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line **110** of file **clar2v.f**.

## Author

Generated automatically by Doxygen for LAPACK from the source code.