NAME

       NGRITD - Given the coordinates of a point, this routine performs a rotation of that point about a
       specified axis by a specified angle.

SYNOPSIS

       CALL NGRITD (IAXS,ANGL,UCRD,VCRD,WCRD)

C-BINDING SYNOPSIS

       #include <ncarg/ncargC.h>

       void c_ngritd(int iaxs, float angl, float *ucrd, float *ycrd,
       float *wcrd)

DESCRIPTION

       IAXS        (an  input  expression of type INTEGER) specifies the axis about which rotation is to be done
                   (1 for the U axis, 2 for the V axis, and 3 for the W axis).

       ANGL        (an input expression of type REAL) specifies the  magnitude,  in  degrees,  of  the  rotation
                   angle.

       UCRD        (an  input/output  variable  of  type  REAL)  specifies  the  U coordinate of the point being
                   rotated.

       VCRD        (an input/output variable of type REAL)  specifies  the  V  coordinate  of  the  point  being
                   rotated.

       WCRD        (an  input/output  variable  of  type  REAL)  specifies  the  W coordinate of the point being
                   rotated.

C-BINDING DESCRIPTION

       The C binding argument descriptions are the same as the FORTRAN argument descriptions.

USAGE

       This routine is used by NGGCOG and NGGSOG to effect the rotations that are used to generate an object  of
       a specified shape at a specified point on the surface of the globe.

       NGRITD  assumes  that  the  UVW coordinate system is right-handed.  Positive values of ANGL give counter-
       clockwise rotations and negative values of ANGL give clockwise rotations.  (When IAXS  =  1,  ANGL  =  90
       carries  the  positive  V  axis into the positive W axis; when IAXS = 2, ANGL = 90 carries the positive W
       axis into the positive U axis; when IAXS = 3, ANGL = 90 carries the positive U axis into the  positive  V
       axis.)

EXAMPLES

       Use the ncargex command to see the following relevant example: cpex10.

ACCESS

       To  use NGRITD or c_ngritd, load the NCAR Graphics libraries ncarg, ncarg_gks, and ncarg_c, preferably in
       that order.

MESSAGES

       None.

SEE ALSO

       Online: nggcog(3NCARG), nggsog(3NCARG).

COPYRIGHT

       Copyright (C) 1987-2009
       University Corporation for Atmospheric Research
       The use of this Software is governed by a License Agreement.

UNIX                                               March 1993                                     NGRITD(3NCARG)