PLSHADE1(3)                       PLplot API                       PLSHADE1(3)



NAME
       plshade1 - Shade individual region on the basis of value

SYNOPSIS
       plshade1(a, nx, ny, defined, xmin, xmax, ymin, ymax, shade_min,
       shade_max, sh_cmap, sh_color, sh_width, min_color, min_width,
       max_color, max_width, fill, rectangular, pltr, pltr_data)

DESCRIPTION
       Shade individual region on the basis of value.  Use plshades(3) if you
       want to shade a number of contiguous regions using continuous colors.
       In particular the edge contours are treated properly in plshades(3). If
       you attempt to do contiguous regions with plshade1(3) (or plshade(3))
       the contours at the edge of the shade are partially obliterated by
       subsequent plots of contiguous shaded regions. plshade1(3) differs from
       plshade(3) by the type of the first argument.  Look at the argument
       list below, plcont(3) and the PLplot documentation for more information
       about the transformation from grid to world coordinates.  Shading NEEDS
       DOCUMENTATION, but as a stopgap look at how plshade(3) is used in
       examples/c/x15c.c

       Redacted form:  General: plshade1(a, defined, xmin, xmax, ymin, ymax,
       shade_min, shade_max, sh_cmap, sh_color, sh_width, min_color,
       min_width, max_color, max_width, fill, rectangular, pltr, pltr_data)
       Perl/PDL: plshade1(a, xmin, xmax, ymin, ymax, shade_min, shade_max,
       sh_cmap, sh_color, sh_width, min_color, min_width, max_color,
       max_width, fill, rectangular, defined, pltr, pltr_data)


       This function is used in example 15.

ARGUMENTS
       a (PLFLT *, input)
              Contains 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
              otherwise. 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 (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
              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.

       shade_min (PLFLT, input)
              Defines the lower end of the interval to be shaded. If shade_max
              <= shade_min, plshade1(3) does nothing.

       shade_max (PLFLT, input)
              Defines the upper end of the interval to be shaded. If shade_max
              <= shade_min, plshade1(3) does nothing.

       sh_cmap (PLINT, input)
              Defines color map.

       sh_color (PLFLT, input)
              Defines color map index if cmap0 or color map input value
              (ranging from 0. to 1.) if cmap1.

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

       min_color (PLINT, input)
              Defines pen color, width used by the boundary of shaded region.
              The min values are used for the shade_min boundary, and the max
              values are used on the shade_max boundary.  Set color and width
              to zero for no plotted boundaries.

       min_width (PLINT, input)
              Defines pen color, width used by the boundary of shaded region.
              The min values are used for the shade_min boundary, and the max
              values are used on the shade_max boundary.  Set color and width
              to zero for no plotted boundaries.

       max_color (PLINT, input)
              Defines pen color, width used by the boundary of shaded region.
              The min values are used for the shade_min boundary, and the max
              values are used on the shade_max boundary.  Set color and width
              to zero for no plotted boundaries.

       max_width (PLINT, input)
              Defines pen color, width used by the boundary of shaded region.
              The min values are used for the shade_min boundary, and the max
              values are used on the shade_max boundary.  Set color and width
              to zero for no plotted boundaries.

       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
              rectangular 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 rectangles. For example a plot in polar coordinates has
              to have rectangular 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
              identity 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).

       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.



                                November, 2007                     PLSHADE1(3)
