
plshade1: Shade individual region on the basis of value 

DESCRIPTION:

    This function is used in example 15. 

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 (const 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 does nothing. 

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

    sh_cmap (PLINT, input) :    Defines color map. If  sh_cmap=0, then
    sh_color is interpreted as a color map 0 (integer) index.  If 
    sh_cmap=1, then sh_color is interpreted as a color map 1
    floating-point index which ranges from 0. to 1. 

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

    sh_width (PLFLT, 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 (PLFLT, 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 (PLFLT, 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, const PLFLT *, const PLFLT *), input) :   
    Routine used to fill the region.  Use plfill.  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 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. 
