# dlar2v (3) - Linux Manuals

dlar2v.f -

## SYNOPSIS

### Functions/Subroutines

subroutine dlar2v (N, X, Y, Z, INCX, C, S, INCC)
DLAR2V applies a vector of plane rotations with real cosines and real sines from both sides to a sequence of 2-by-2 symmetric/Hermitian matrices.

## Function/Subroutine Documentation

### subroutine dlar2v (integerN, double precision, dimension( * )X, double precision, dimension( * )Y, double precision, dimension( * )Z, integerINCX, double precision, dimension( * )C, double precision, dimension( * )S, integerINCC)

DLAR2V applies a vector of plane rotations with real cosines and real sines from both sides to a sequence of 2-by-2 symmetric/Hermitian matrices.

Purpose:

``` DLAR2V applies a vector of real plane rotations from both sides to
a sequence of 2-by-2 real symmetric matrices, defined by the elements
of the vectors x, y and z. For i = 1,2,...,n

( x(i)  z(i) ) := (  c(i)  s(i) ) ( x(i)  z(i) ) ( c(i) -s(i) )
( z(i)  y(i) )    ( -s(i)  c(i) ) ( z(i)  y(i) ) ( s(i)  c(i) )
```

Parameters:

N

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

X

```          X is DOUBLE PRECISION array,
dimension (1+(N-1)*INCX)
The vector x.
```

Y

```          Y is DOUBLE PRECISION array,
dimension (1+(N-1)*INCX)
The vector y.
```

Z

```          Z is DOUBLE PRECISION 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 DOUBLE PRECISION array, dimension (1+(N-1)*INCC)
The cosines of the plane rotations.
```

S

```          S is DOUBLE PRECISION 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