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comparison FIXES/contour.m @ 0:6b33357c7561 octave-forge

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Initial revision
author pkienzle
date Wed, 10 Oct 2001 19:54:49 +0000
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children 2ac2777b30bc
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-1:000000000000 0:6b33357c7561
1 ## Copyright (C) 1996, 1997 John W. Eaton
2 ##
3 ## This file is part of Octave.
4 ##
5 ## Octave is free software; you can redistribute it and/or modify it
6 ## under the terms of the GNU General Public License as published by
7 ## the Free Software Foundation; either version 2, or (at your option)
8 ## any later version.
9 ##
10 ## Octave is distributed in the hope that it will be useful, but
11 ## WITHOUT ANY WARRANTY; without even the implied warranty of
12 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 ## General Public License for more details.
14 ##
15 ## You should have received a copy of the GNU General Public License
16 ## along with Octave; see the file COPYING. If not, write to the Free
17 ## Software Foundation, 59 Temple Place - Suite 330, Boston, MA
18 ## 02111-1307, USA.
19
20 ## -*- texinfo -*-
21 ## @deftypefn {Function File} {} contour (@var{z}, @var{n})
22 ## @deftypefnx {Function File} {} contour (@var{x}, @var{y}, @var{z}, @var{n})
23 ## Make a contour plot of the three-dimensional surface described by
24 ## @var{z}. Someone needs to improve @code{gnuplot}'s contour routines
25 ## before this will be very useful.
26 ## @end deftypefn
27 ## @seealso{plot, semilogx, semilogy, loglog, polar, mesh, contour,
28 ## bar, stairs, gplot, gsplot, replot, xlabel, ylabel, and title}
29
30 ## Author: jwe
31 ## Paul Kienzle <pkienzle@kienzle.powernet.co.uk>
32 ## matlab compatible interface
33
34 function contour (x, y, z, n)
35
36 ## XXX FIXME XXX -- these plot states should really just be set
37 ## temporarily, probably inside an unwind_protect block, but there is
38 ## no way to determine their current values.
39
40 if (nargin == 1 || nargin == 2)
41 z = x;
42 if (nargin == 1)
43 n = 10;
44 else
45 n = y;
46 endif
47 if (is_matrix (z))
48 gset nosurface;
49 gset contour;
50 gset cntrparam bspline;
51 if (is_scalar (n))
52 command = sprintf ("gset cntrparam levels %d", n);
53 elseif (is_vector (n))
54 tmp = sprintf ("%f", n(1));
55 for i = 2:length (n)
56 tmp = sprintf ("%s, %f", tmp, n(i));
57 endfor
58 command = sprintf ("gset cntrparam levels discrete %s", tmp);
59 endif
60 eval (command);
61 gset noparametric;
62 gset view 0, 0, 1, 1;
63 gsplot z w l 1;
64 else
65 error ("contour: argument must be a matrix");
66 endif
67 elseif (nargin == 3 || nargin == 4)
68 if (nargin == 3) n = 9; endif
69 if (is_vector (x) && is_vector (y) && is_matrix (z))
70 xlen = length (x);
71 ylen = length (y);
72 if (xlen == rows (z) && ylen == columns (z))
73 if (rows (x) == 1)
74 x = x';
75 endif
76 len = 3 * ylen;
77 zz = zeros (xlen, len);
78 k = 1;
79 for i = 1:3:len
80 zz(:,i) = x;
81 zz(:,i+1) = y(k) * ones (xlen, 1);
82 zz(:,i+2) = z(:,k);
83 k++;
84 endfor
85 gset nosurface;
86 gset contour;
87 gset cntrparam bspline;
88 if (is_scalar (n))
89 command = sprintf ("gset cntrparam levels %d", n);
90 elseif (is_vector (n))
91 tmp = sprintf ("%f", n(1));
92 for i = 2:length (n)
93 tmp = sprintf ("%s, %f", tmp, n(i));
94 endfor
95 command = sprintf ("gset cntrparam levels discrete %s", tmp);
96 endif
97 eval (command);
98 gset parametric;
99 gset view 0, 0, 1, 1;
100 gsplot zz w l 1;
101 else
102 msg = "contour: rows (z) must be the same as length (x) and";
103 msg = sprintf ("%s\ncolumns (z) must be the same as length (y)", msg);
104 error (msg);
105 endif
106 else
107 error ("contour: x and y must be vectors and z must be a matrix");
108 endif
109 else
110 usage ("contour (z, levels, x, y)");
111 endif
112
113 endfunction