


PLSHADES(3)                 PLplot API                PLSHADES(3)


NAME
       plshades - Shade regions on the basis of value

SYNOPSIS
       plshades(a,  nx,  ny,  defined, xmin, xmax, ymin, ymax, clevel, nlevel,
       fill_width, cont_color, cont_width, fill, rectangular, pltr, pltr_data)

DESCRIPTION
       Shade  regions  on  the basis of value.  This is the high-level routine
       for making continuous color shaded plots with  cmap1  while  plshade(3)
       (or  plshade1(3))  are  used for individual shaded regions using either
       cmap0 or cmap1. examples/c/x16c.c shows a number of examples for  using
       this  function.  See  the following discussion of the arguments and the
       PLplot documentation for more information.

       Redacted form:  General: plshades(a, defined, xmin, xmax,  ymin,  ymax,
       clevel,  fill_width,  cont_color,  cont_width, fill, rectangular, pltr,
       pltr_data)  Perl/PDL:  plshades(a,  xmin,  xmax,  ymin,  ymax,  clevel,
       fill_width,  cont_color,  cont_width, fill, rectangular, defined, pltr,
       pltr_data)


       This function is used in examples 16,21.

ARGUMENTS
       a (PLFLT **, input)
              Contains ** pointer to array to be plotted. The array must  have
              been declared as PLFLT a[nx][ny].

       nx (PLINT, input)
              First dimension of array "a".

       ny (PLINT, input)
              Second dimension of array "a".

       defined (PLINT (*) (PLFLT, PLFLT), input)
              User function specifying regions excluded from the shading plot.
              This function accepts x and y coordinates as input arguments and
              must return 0 if the point is in the excluded region or 1 other-
              wise. This argument can be NULL if all the values are valid.

       xmin (PLFLT, input)
              Defines the "grid" coordinates.  The data a[0][0] has a position
              of  (xmin,ymin), a[nx-1][0] has a position at (xmax,ymin) and so
              on.  (xmax,ymin)

       xmax (PLFLT, input)
              Defines the "grid" coordinates.  The data a[0][0] has a position
              of  (xmin,ymin), a[nx-1][0] has a position at (xmax,ymin) and so
              on.

       ymin (PLFLT, input)
              Defines the "grid" coordinates.  The data a[0][0] has a position
              of  (xmin,ymin), a[nx-1][0] has a position at (xmax,ymin) and so



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PLSHADES(3)                 PLplot API                PLSHADES(3)


              on.

       ymax (PLFLT, input)
              Defines the "grid" coordinates.  The data a[0][0] has a position
              of  (xmin,ymin), a[nx-1][0] has a position at (xmax,ymin) and so
              on.

       clevel (PLFLT *, input)
              Pointer to array containing the data levels corresponding to the
              edges  of  each shaded region that will be plotted by this func-
              tion.  To work properly the levels should be monotonic.

       nlevel (PLINT, input)
              Number of shades plus 1 (i.e., the number of shade  edge  values
              in clevel).

       fill_width (PLINT, input)
              Defines width used by the fill pattern.

       cont_color (PLINT, input)
              Defines  pen  color  used  for contours defining edges of shaded
              regions.  The pen color is only temporary set  for  the  contour
              drawing.   Set  this value to zero or less if no shade edge con-
              tours are wanted.

       cont_width (PLINT, input)
              Defines pen width used for contours  defining  edges  of  shaded
              regions.   This value may not be honored by all drivers. The pen
              width is only temporary set for the contour drawing.   Set  this
              value to zero or less if no shade edge contours are wanted.

       fill (void (*) (PLINT, PLFLT *, PLFLT *), input)
              Routine used to fill the region.  Use plfill(3).  Future version
              of PLplot may have other fill routines.

       rectangular (PLBOOL, input)
              Set rectangular to true if rectangles map  to  rectangles  after
              coordinate  transformation with pltrl.  Otherwise, set rectangu-
              lar to false. If rectangular is set to true,  plshade  tries  to
              save  time by filling large rectangles.  This optimization fails
              if the coordinate transformation distorts the shape  of  rectan-
              gles. For example a plot in polar coordinates has to have  rect-
              angular set to false.

       pltr (void (*) (PLFLT, PLFLT, PLFLT *, PLFLT *, PLPointer) , input)
              Pointer to function that defines transformation between  indices
              in  array  z and the world coordinates (C only).  Transformation
              functions are provided in the PLplot library: pltr0(3) for iden-
              tity  mapping,  and pltr1(3) and pltr2(3) for arbitrary mappings
              respectively defined by one-  and  two-dimensional  arrays.   In
              addition,  user-supplied  routines for the transformation can be
              used as well.  Examples of all of these approaches are given  in
              the  PLplot  documentation.  The  transformation function should
              have the form given by any of pltr0(3), pltr1(3), or pltr2(3).



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PLSHADES(3)                 PLplot API                PLSHADES(3)


       pltr_data (PLPointer, input)
              Extra parameter to help pass information to pltr0(3),  pltr1(3),
              pltr2(3), or whatever routine that is externally supplied.


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.












































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