[ новости /+++ | форум | теги | ]

NAME
     dlartg - generate a plane rotation so that   [ CS SN ]

SYNOPSIS
     SUBROUTINE DLARTG( F, G, CS, SN, R )

     DOUBLE PRECISION CS, F, G, R, SN



     #include <sunperf.h>

     void dlartg(double f, double g, double *cs, double *sn, dou-
               ble *r) ;

PURPOSE
     DLARTG generate a plane rotation so that
        [ -SN  CS  ]     [ G ]     [ 0 ]

     This is a slower, more accurate version of the BLAS1 routine
     DROTG, with the following other differences:
        F and G are unchanged on return.
        If G=0, then CS=1 and SN=0.
        If F=0 and (G .ne. 0), then CS=0 and SN=1  without  doing
     any
           floating point operations (saves work in DBDSQR when
           there are zeros on the diagonal).

     If F exceeds G in magnitude, CS will be positive.


ARGUMENTS
     F         (input) DOUBLE PRECISION
               The first component of vector to be rotated.

     G         (input) DOUBLE PRECISION
               The second component of vector to be rotated.

     CS        (output) DOUBLE PRECISION
               The cosine of the rotation.

     SN        (output) DOUBLE PRECISION
               The sine of the rotation.

     R         (output) DOUBLE PRECISION
               The nonzero component of the rotated vector.

Партнёры:

Хостинг: