1PLSHADES(3plplot) PLplot API PLSHADES(3plplot)
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6 plshades - Shade regions on the basis of value
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9 plshades(a, nx, ny, defined, xmin, xmax, ymin, ymax, clevel, nlevel,
10 fill_width, cont_color, cont_width, fill, rectangular, pltr, pltr_data)
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13 Shade regions on the basis of value. This is the high-level routine
14 for making continuous color shaded plots with cmap1 while
15 plshade(3plplot) should be used to plot individual shaded regions using
16 either cmap0 or cmap1. examples/;<language>/x16* shows how to use
17 plshades(3plplot) for each of our supported languages.
18 Redacted form: General: plshades(a, defined, xmin, xmax, ymin, ymax,
20 clevel, fill_width, cont_color, cont_width, fill, rectangular, pltr,
21 pltr_data) Perl/PDL: plshades(a, xmin, xmax, ymin, ymax, clevel,
22 fill_width, cont_color, cont_width, fill, rectangular, defined, pltr,
23 pltr_data)
24 This function is used in examples 16, 21, and 22.
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29 a (PLFLT_MATRIX(3plplot), input)
30 A matrix containing function values to plot. Should have dimen‐
31 sions of nx by ny.
32 nx (PLINT(3plplot), input)
34 First dimension of matrix "a".
35 ny (PLINT(3plplot), input)
37 Second dimension of matrix "a".
38 defined (PLDEFINED_callback(3plplot), input)
40 Callback function specifying the region that should be plotted
41 in the shade plot. This function accepts x and y coordinates as
42 input arguments and must return 1 if the point is to be included
43 in the shade plot and 0 otherwise. If you want to plot the
44 entire shade plot (the usual case), this argument should be set
45 to NULL.
46 xmin, xmax, ymin, ymax (PLFLT(3plplot), input)
48 See the discussion of pltr below for how these arguments are
49 used (only for the special case when the callback function pltr
50 is not supplied).
51 clevel (PLFLT_VECTOR(3plplot), input)
53 A vector containing the data levels corresponding to the edges
54 of each shaded region that will be plotted by this function. To
55 work properly the levels should be monotonic.
56 nlevel (PLINT(3plplot), input)
58 Number of shades plus 1 (i.e., the number of shade edge values
59 in clevel).
60 fill_width (PLFLT(3plplot), input)
62 Defines the line width used by the fill pattern.
63 cont_color (PLINT(3plplot), input)
65 Defines cmap0 pen color used for contours defining edges of
66 shaded regions. The pen color is only temporary set for the
67 contour drawing. Set this value to zero or less if no shade
68 edge contours are wanted.
69 cont_width (PLFLT(3plplot), input)
71 Defines line width used for contours defining edges of shaded
72 regions. This value may not be honored by all drivers. The pen
73 width is only temporary set for the contour drawing. Set this
74 value to zero or less if no shade edge contours are wanted.
75 fill (PLFILL_callback(3plplot), input)
77 Callback routine used to fill the region. Use plfill(3plplot)
78 for this purpose.
79 rectangular (PLBOOL(3plplot), input)
81 Set rectangular to true if rectangles map to rectangles after
82 coordinate transformation with pltrl. Otherwise, set rectangu‐
83 lar to false. If rectangular is set to true, plshade tries to
84 save time by filling large rectangles. This optimization fails
85 if the coordinate transformation distorts the shape of rectan‐
86 gles. For example a plot in polar coordinates has to have rec‐
87 tangular set to false.
88 pltr (PLTRANSFORM_callback(3plplot), input)
90 A callback function that defines the transformation between the
91 zero-based indices of the matrix a and world coordinates. If
92 pltr is not supplied (e.g., is set to NULL in the C case), then
93 the x indices of a are mapped to the range xmin through xmax and
94 the y indices of a are mapped to the range ymin through ymax.For
95 the C case, transformation functions are provided in the PLplot
96 library: pltr0(3plplot) for the identity mapping, and
97 pltr1(3plplot) and pltr2(3plplot) for arbitrary mappings respec‐
98 tively defined by vectors and matrices. In addition, C callback
99 routines for the transformation can be supplied by the user such
100 as the mypltr function in examples/c/x09c.c which provides a
101 general linear transformation between index coordinates and
102 world coordinates.For languages other than C you should consult
103 the PLplot documentation for the details concerning how PLTRANS‐
104 FORM_callback(3plplot) arguments are interfaced. However, in
105 general, a particular pattern of callback-associated arguments
106 such as a tr vector with 6 elements; xg and yg vectors; or xg
107 and yg matrices are respectively interfaced to a linear-trans‐
108 formation routine similar to the above mypltr function;
109 pltr1(3plplot); and pltr2(3plplot). Furthermore, some of our
110 more sophisticated bindings (see, e.g., the PLplot documenta‐
111 tion) support native language callbacks for handling index to
112 world-coordinate transformations. Examples of these various
113 approaches are given in examples/<language>x09*, examples/<lan‐
114 guage>x16*, examples/<language>x20*, examples/<language>x21*,
115 and examples/<language>x22*, for all our supported languages.
116 pltr_data (PLPointer(3plplot), input)
118 Extra parameter to help pass information to pltr0(3plplot),
119 pltr1(3plplot), pltr2(3plplot), or whatever routine that is
120 externally supplied.
121
124 Many developers (who are credited at http://plplot.source‐
125 forge.net/credits.php) have contributed to PLplot over its long his‐
126 tory.
127
129 PLplot documentation at http://plplot.sourceforge.net/documenta‐
130 tion.php.
131 August, 2017 PLSHADES(3plplot)