1PLVECT(3plplot) PLplot API PLVECT(3plplot)
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6 plvect - Vector plot
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9 plvect(u, v, nx, ny, scale, pltr, pltr_data)
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12 Draws a plot of vector data contained in the matrices
13 (u[nx][ny],v[nx][ny]) . The scaling factor for the vectors is given by
14 scale. A transformation routine pointed to by pltr with a pointer
15 pltr_data for additional data required by the transformation routine to
16 map indices within the matrices to the world coordinates. The style of
17 the vector arrow may be set using plsvect(3plplot).
18 Redacted form: plvect(u, v, scale, pltr, pltr_data) where (see above
20 discussion) the pltr, pltr_data callback arguments are sometimes
21 replaced by a tr vector with 6 elements, or xg and yg array arguments
22 with either one or two dimensions.
23 This function is used in example 22.
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27 u, v (PLFLT_MATRIX(3plplot), input)
28 A pair of matrices containing the x and y components of the vec‐
29 tor data to be plotted.
30 nx, ny (PLINT(3plplot), input)
32 Dimensions of the matrices u and v.
33 scale (PLFLT(3plplot), input)
35 Parameter to control the scaling factor of the vectors for plot‐
36 ting. If scale = 0 then the scaling factor is automatically
37 calculated for the data. If scale < 0 then the scaling factor is
38 automatically calculated for the data and then multiplied by
39 -scale. If scale > 0 then the scaling factor is set to scale.
40 pltr (PLTRANSFORM_callback(3plplot), input)
42 A callback function that defines the transformation between the
43 zero-based indices of the matrices u and v and world coordi‐
44 nates.For the C case, transformation functions are provided in
45 the PLplot library: pltr0(3plplot) for the identity mapping, and
46 pltr1(3plplot) and pltr2(3plplot) for arbitrary mappings respec‐
47 tively defined by vectors and matrices. In addition, C callback
48 routines for the transformation can be supplied by the user such
49 as the mypltr function in examples/c/x09c.c which provides a
50 general linear transformation between index coordinates and
51 world coordinates.For languages other than C you should consult
52 the PLplot documentation for the details concerning how PLTRANS‐
53 FORM_callback(3plplot) arguments are interfaced. However, in
54 general, a particular pattern of callback-associated arguments
55 such as a tr vector with 6 elements; xg and yg vectors; or xg
56 and yg matrices are respectively interfaced to a linear-trans‐
57 formation routine similar to the above mypltr function;
58 pltr1(3plplot); and pltr2(3plplot). Furthermore, some of our
59 more sophisticated bindings (see, e.g., the PLplot documenta‐
60 tion) support native language callbacks for handling index to
61 world-coordinate transformations. Examples of these various
62 approaches are given in examples/<language>x09*, examples/<lan‐
63 guage>x16*, examples/<language>x20*, examples/<language>x21*,
64 and examples/<language>x22*, for all our supported languages.
65 pltr_data (PLPointer(3plplot), input)
67 Extra parameter to help pass information to pltr0(3plplot),
68 pltr1(3plplot), pltr2(3plplot), or whatever callback routine
69 that is externally supplied.
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73 Many developers (who are credited at http://plplot.org/credits.php)
74 have contributed to PLplot over its long history.
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77 PLplot documentation at http://plplot.org/documentation.php.
78 February, 2019 PLVECT(3plplot)