plshades
( | a , |
nx , | |
ny , | |
defined , | |
xmin , | |
xmax , | |
ymin , | |
ymax , | |
clevel , | |
nlevel , | |
fill_width , | |
cont_color , | |
cont_width , | |
fill , | |
rectangular , | |
pltr , | |
pltr_data
) ; |
Shade regions on the basis of value. This is the high-level routine
for making continuous color shaded plots with cmap1 while
plshade
should be used to plot individual shaded regions
using either cmap0 or cmap1.
examples/;<language>/x16*
shows how to use
plshades
for each of our supported languages.
a
(PLFLT_MATRIX
, input)
A matrix containing function values to plot. Should have
dimensions of nx
by ny
.
nx
(PLINT
, input)
First dimension of matrix "a".
ny
(PLINT
, input)
Second dimension of matrix "a".
defined
(PLDEFINED_callback
, 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
, 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).
clevel
(PLFLT_VECTOR
, input)
A vector containing the data levels corresponding to the edges of each shaded region that will be plotted by this function. To work properly the levels should be monotonic.
nlevel
(PLINT
, input)
Number of shades plus 1 (i.e., the number of shade edge values
in
).clevel
fill_width
(PLFLT
, input)
Defines the line width used by the fill pattern.
cont_color
(PLINT
, input)
Defines cmap0 pen color used for contours defining edges of shaded regions. The pen color is only temporary set for the contour drawing. Set this value to zero or less if no shade edge contours are wanted.
cont_width
(PLFLT
, input)
Defines line width used for contours defining edges of shaded regions. This value may not be honored by all drivers. The pen width is only temporary set for the contour drawing. Set this value to zero or less if no shade edge contours are wanted.
fill
(PLFILL_callback
, input)
Callback routine used to fill the region. Use plfill
for this purpose.
rectangular
(PLBOOL
, input)
Set
to
true if rectangles map to rectangles after coordinate transformation
with rectangular
. Otherwise,
set pltrl
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.rectangular
pltr
(PLTRANSFORM_callback
, input)
A callback function that defines the transformation
between the zero-based indices of the matrix
and world coordinates.
If a
pltr
is not supplied (e.g., is set to NULL
in the C case), then the x indices of
are mapped to the range
a
xmin
through xmax
and
the y indices of
are
mapped to the range a
ymin
through
ymax
.
For the C case, transformation functions are provided
in the PLplot library: pltr0
for the identity mapping, and pltr1
and pltr2
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 Part III, “ Supported computer languages ” for the details concerning how
PLTRANSFORM_callback
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
; and pltr2
.
Furthermore, some of our more sophisticated bindings (see, e.g., Chapter 10, Fortran Language) 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
, input)
Extra parameter to help
pass information to pltr0
, pltr1
, pltr2
, or whatever routine
that is externally supplied.
Redacted form:
General: plshades(a, defined, xmin, xmax, ymin, ymax, clevel, fill_width, cont_color, cont_width, fill, rectangular, pltr, pltr_data)
This function is used in examples 16, 21, and 22.