debian man page for plgradient

PLGRADIENT(3plplot)						    PLplot API						       PLGRADIENT(3plplot)

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  vec-
       tor  can  be interpreted as being anywhere on the line corresponding to the minimum x value for the vertices in the rotated coordinate sys-
       tem.  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 indepen-
       dent 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 (PLFLT *, input)
	      Pointer to array with x coordinates of vertices.

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

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

AUTHORS
       Geoffrey Furnish and Maurice LeBrun wrote and maintain PLplot.  This man page was automatically generated from the DocBook  source  of  the
       PLplot documentation, maintained by Alan W. Irwin and Rafael Laboissiere.

SEE ALSO
       PLplot documentation at http://plplot.sourceforge.net/resources.

								   August, 2012 					       PLGRADIENT(3plplot)