
plshade1: Shade individual region on the basis of value 

DESCRIPTION:

    Shade individual region on the basis of value.  Use plshades if you
    want to shade a number of contiguous regions using continuous colors. 
    In particular the edge contours are treated properly in plshades. If
    you attempt to do contiguous regions with plshade1 (or plshade) the
    contours at the edge of the shade are partially obliterated by
    subsequent plots of contiguous shaded regions. plshade1 differs from
    plshade by the type of the first argument.	Look at the argument list
    below, plcont 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 is used in
    examples/c/x15c.c

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)

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). 

    xmax (PLFLT, input) :    Defines the "grid" coordinates.  The data
    a[0][0] has a position of (xmin,ymin). 

    ymin (PLFLT, input) :    Defines the "grid" coordinates.  The data
    a[0][0] has a position of (xmin,ymin). 

    ymax (PLFLT, input) :    Defines the "grid" coordinates.  The data
    a[0][0] has a position of (xmin,ymin). 

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

    shade_max (PLFLT, input) :      Defines the interval to be shaded. If
    shade_max <= shade_min, plshade1 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.  Future version of plplot may have
    other fill routines. 

    rectangular (PLINT, input) :    Set rectangular to 1 if rectangles map
    to rectangles after coordinate transformation with pltrl. 
    Otherwise, set rectangular to 0. If rectangular is set to 1,
    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 polor coordinates has
    to have rectangular set to 0. 

    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 for identity
    mapping, and pltr1 and pltr2 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, pltr1, or pltr2. 

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