# clacrt.f

Section: LAPACK (3)
Updated: Tue Nov 14 2017
Page Index

clacrt.f

## SYNOPSIS

### Functions/Subroutines

subroutine clacrt (N, CX, INCX, CY, INCY, C, S)
CLACRT performs a linear transformation of a pair of complex vectors.

## Function/Subroutine Documentation

### subroutine clacrt (integer N, complex, dimension( * ) CX, integer INCX, complex, dimension( * ) CY, integer INCY, complex C, complex S)

CLACRT performs a linear transformation of a pair of complex vectors.

Purpose:

``` CLACRT performs the operation

(  c  s )( x )  ==> ( x )
( -s  c )( y )      ( y )

where c and s are complex and the vectors x and y are complex.
```

Parameters:

N

```          N is INTEGER
The number of elements in the vectors CX and CY.
```

CX

```          CX is COMPLEX array, dimension (N)
On input, the vector x.
On output, CX is overwritten with c*x + s*y.
```

INCX

```          INCX is INTEGER
The increment between successive values of CX.  INCX <> 0.
```

CY

```          CY is COMPLEX array, dimension (N)
On input, the vector y.
On output, CY is overwritten with -s*x + c*y.
```

INCY

```          INCY is INTEGER
The increment between successive values of CY.  INCY <> 0.
```

C

```          C is COMPLEX
```

S

```          S is COMPLEX
C and S define the matrix
[  C   S  ].
[ -S   C  ]
```

Author:

Univ. of Tennessee

Univ. of California Berkeley