Contents

• NAME
• SYNOPSIS
  • F95 INTERFACE
  • C INTERFACE
• PURPOSE
• ARGUMENTS

NAME

     zrotg - Construct a Given's plane rotation

SYNOPSIS

     SUBROUTINE ZROTG(A, B, C, S)

     DOUBLE COMPLEX A, B, S
     DOUBLE PRECISION C

     SUBROUTINE ZROTG_64(A, B, C, S)

     DOUBLE COMPLEX A, B, S
     DOUBLE PRECISION C

  F95 INTERFACE
     SUBROUTINE ROTG(A, B, C, S)

     COMPLEX(8) :: A, B, S
     REAL(8) :: C

     SUBROUTINE ROTG_64(A, B, C, S)

     COMPLEX(8) :: A, B, S
     REAL(8) :: C

  C INTERFACE
     #include <sunperf.h>

     void zrotg(doublecomplex *a, doublecomplex  *b,  double  *c,
               doublecomplex *s);

     void zrotg_64(doublecomplex *a, doublecomplex *b, double *c,
               doublecomplex *s);

PURPOSE

     zrotg Construct a Given's plane rotation that  will  annihi-
     late an element of a vector.

ARGUMENTS

     A (input/output)
               On entry, A contains the entry in the first vector
               that  corresponds to the element to be annihilated
               in  the  second  vector.  On  exit,  contains  the
               nonzero element of the rotated vector.
     B (input)
               On entry, B contains the entry to  be  annihilated
               in the second vector.  Unchanged on exit.

     C (output)
               On exit, C and S are the elements of the  rotation
               matrix that will be applied to annihilate B.

     S (output)
               On exit, C and S are the elements of the  rotation
               matrix that will be applied to annihilate B.