[ Previous |
Next |
Contents |
Glossary |
Home |
Search ]

*AIX Version 4.3 Base Operating System and Extensions Technical Reference, Volume 2*

## SROT, DROT, CSROT, or ZDROT Subroutine

### Purpose

Applies a plane rotation.

### Library

BLAS Library (**libblas.a**)

### FORTRAN Syntax

**SUBROUTINE SROT(***N***,***X***,***INCX***,***Y***,***INCY***,***C***,***S***)**
**INTEGER ***INCX***,***INCY***,***N*
**REAL ***C***,***S*
**REAL ***X***(*),***Y***(*)**

**SUBROUTINE DROT(***N***,***X***,***INCX***,***Y***,***INCY***,***C***,***S***)**
**INTEGER ***INCX***,***INCY***,***N*
**DOUBLE PRECISION ***C***,***S*
**DOUBLE PRECISION ***X***(*),***Y***(*)**

**SUBROUTINE CSROT(***N***,***X***,***INCX***,***Y***,***INCY***,***C***,***S***)**
**INTEGER ***INCX***,***INCY***,***N*
**REAL ***C***,***S*
**COMPLEX ***X***(*),***Y***(*)**

**SUBROUTINE ZDROT(***N***,***X***,***INCX***,***Y***,***INCY***,***C***,***S***)**
**INTEGER ***INCX***,***INCY***,***N*
**DOUBLE PRECISION ***C***,***S*
**COMPLEX*16 ***X***(*),***Y***(*)**

### Description

The **SROT**, **DROT**, **CSROT,** or **ZDROT** subroutine computes:

--- --- --- --- --- ---
| X | | C S | | X |
| i | | | | i |
| | := | | . | | for i = 1, ..., N.
| Y | | | | Y |
| i | | -S C | | i |
--- --- --- --- --- ---

The subroutines return the modified *X* and *Y*.

### Parameters

*N* |
On entry, *N* specifies the number of elements in *X* and *Y*; unchanged on exit. |

*X* |
Vector of dimension at least (1 + (*N*-1) * abs (*INCX*) ); unchanged on exit. |

*INCX* |
On entry, *INCX* specifies the increment for the elements of *X*; unchanged on exit. |

*Y* |
Vector of dimension at least (1 + (*N*-1) * abs(*INCY*) ); modified on exit. |

*INCY* |
On entry, *INCY* specifies the increment for the elements of *Y*; unchanged on exit. |

*C* |
Scalar constant; unchanged on exit. |

*S* |
Scalar constant; unchanged on exit. |

### Error Codes

If *N* <= 0, or if *C* = 1 and *S* = 0, the subroutines return immediately.

[ Previous |
Next |
Contents |
Glossary |
Home |
Search ]