plshade - Shade individual region on the basis of value
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)
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.
- 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.
Many developers (who are credited at
http://plplot.org/credits.php) have contributed to PLplot over its long
history.
PLplot documentation at http://plplot.org/documentation.php.