NAME

       plgradient - Draw linear gradient inside polygon

SYNOPSIS

       plgradient(n, x, y, angle)

DESCRIPTION

       Draw  a  linear  gradient  using  colour  map  1 inside the polygon defined by the n points (x[i], y[i]).
       Interpretation of the polygon is the same as  for  plfill(3plplot).   The  polygon  coordinates  and  the
       gradient  angle  are  all expressed in world coordinates.  The angle from the x axis for both the rotated
       coordinate system and the gradient vector is specified by angle.  The magnitude of the gradient vector is
       the  difference  between  the  maximum and minimum values of x for the vertices in the rotated coordinate
       system.  The origin of the gradient vector can be interpreted as being anywhere on the line corresponding
       to  the  minimum  x  value  for  the  vertices  in the rotated coordinate system.  The distance along the
       gradient vector is linearly transformed to the independent variable of colour map 1 which ranges from  0.
       at  the  tail of the gradient vector to 1. at the head of the gradient vector.  What is drawn is the RGBA
       colour corresponding to the independent variable of colour map 1.  For more information about colour  map
       1 (see the PLplot documentation).

       Redacted form: plgradient(x,y,angle)

       This function is used in examples 25,30.

ARGUMENTS

       n (PLINT, input)
              Number of vertices in polygon.

       x (const PLFLT *, input)
              Pointer to array with x coordinates of vertices.

       y (const PLFLT *, input)
              Pointer to array with y coordinates of vertices.

       angle (PLFLT, input)
              Angle (degrees) of gradient vector from x axis.

AUTHORS

       Many  developers  (who  are  credited  at  http://plplot.sourceforge.net/credits.php) have contributed to
       PLplot over its long history.

SEE ALSO

       PLplot documentation at http://plplot.sourceforge.net/documentation.php.

                                                 February, 2016                              PLGRADIENT(3plplot)