Provided by: plplot-doc_5.13.0+dfsg-6ubuntu2_all 
NAME
plshade - Shade individual region on the basis of value
SYNOPSIS
plshade(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(3plplot) if you want to shade
a number of contiguous regions using continuous colors. In particular the edge contours
are treated properly in plshades(3plplot). If you attempt to do contiguous regions with
plshade(3plplot) the contours at the edge of the shade are partially obliterated by
subsequent plots of contiguous shaded regions.
Redacted form: General: plshade(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)
This function is used in example 15.
ARGUMENTS
a (PLFLT_MATRIX(3plplot), input)
A matrix containing function values to plot. Should have dimensions of nx by ny.
nx (PLINT(3plplot), input)
First dimension of the matrix "a".
ny (PLINT(3plplot), input)
Second dimension of the matrix "a".
defined (PLDEFINED_callback(3plplot), input)
Callback function specifying the region that should be plotted in the shade plot.
This function accepts x and y coordinates as input arguments and must return 1 if
the point is to be included in the shade plot and 0 otherwise. If you want to plot
the entire shade plot (the usual case), this argument should be set to NULL.
xmin, xmax, ymin, ymax (PLFLT(3plplot), input)
See the discussion of pltr below for how these arguments are used (only for the
special case when the callback function pltr is not supplied).
shade_min (PLFLT(3plplot), input)
Defines the lower end of the interval to be shaded. If shade_max <= shade_min,
plshade(3plplot) does nothing.
shade_max (PLFLT(3plplot), input)
Defines the upper end of the interval to be shaded. If shade_max <= shade_min,
plshade(3plplot) does nothing.
sh_cmap (PLINT(3plplot), input)
Defines color map. If sh_cmap=0, then sh_color is interpreted as a cmap0 (integer)
index. If sh_cmap=1, then sh_color is interpreted as a cmap1 argument in the range
(0.0-1.0).
sh_color (PLFLT(3plplot), input)
Defines color map index with integer value if cmap0 or value in range (0.0-1.0) if
cmap1.
sh_width (PLFLT(3plplot), input)
Defines width used by the fill pattern.
min_color (PLINT(3plplot), 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(3plplot), 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(3plplot), 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(3plplot), 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 (PLFILL_callback(3plplot), input)
Routine used to fill the region. Use plfill(3plplot). Future version of PLplot
may have other fill routines.
rectangular (PLBOOL(3plplot), 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 (PLTRANSFORM_callback(3plplot), input)
A callback function that defines the transformation between the zero-based indices
of the matrix a and world coordinates. If pltr is not supplied (e.g., is set to
NULL in the C case), then the x indices of a are mapped to the range xmin through
xmax and the y indices of a are mapped to the range ymin through ymax.For the C
case, transformation functions are provided in the PLplot library: pltr0(3plplot)
for the identity mapping, and pltr1(3plplot) and pltr2(3plplot) for arbitrary
mappings respectively defined by vectors and matrices. In addition, C callback
routines for the transformation can be supplied by the user such as the mypltr
function in examples/c/x09c.c which provides a general linear transformation
between index coordinates and world coordinates.For languages other than C you
should consult the PLplot documentation for the details concerning how
PLTRANSFORM_callback(3plplot) arguments are interfaced. However, in general, a
particular pattern of callback-associated arguments such as a tr vector with 6
elements; xg and yg vectors; or xg and yg matrices are respectively interfaced to a
linear-transformation routine similar to the above mypltr function; pltr1(3plplot);
and pltr2(3plplot). Furthermore, some of our more sophisticated bindings (see,
e.g., the PLplot documentation) support native language callbacks for handling
index to world-coordinate transformations. Examples of these various approaches
are given in examples/<language>x09*, examples/<language>x16*,
examples/<language>x20*, examples/<language>x21*, and examples/<language>x22*, for
all our supported languages.
pltr_data (PLPointer(3plplot), input)
Extra parameter to help pass information to pltr0(3plplot), pltr1(3plplot),
pltr2(3plplot), or whatever routine that is externally supplied.
AUTHORS
Many developers (who are credited at http://plplot.sourceforge.net/credits.php) have
contributed to PLplot over its long history.
SEE ALSO
PLplot documentation at http://plplot.sourceforge.net/documentation.php.
November, 2017 PLSHADE(3plplot)