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comparison scripts/testfun/demo.m @ 5589:f812a0680d05

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[project @ 2006-01-06 00:14:42 by jwe]
author jwe
date Fri, 06 Jan 2006 00:14:42 +0000
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children 2618a0750ae6
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5588:79ec73a1ff15 5589:f812a0680d05
1 ## Copyright (C) 2000 Paul Kienzle
2 ##
3 ## This program is free software; you can redistribute it and/or modify
4 ## it under the terms of the GNU General Public License as published by
5 ## the Free Software Foundation; either version 2 of the License, or
6 ## (at your option) any later version.
7 ##
8 ## This program is distributed in the hope that it will be useful,
9 ## but WITHOUT ANY WARRANTY; without even the implied warranty of
10 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 ## GNU General Public License for more details.
12 ##
13 ## You should have received a copy of the GNU General Public License
14 ## along with this program; if not, write to the Free Software
15 ## Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
16 ## 02110-1301 USA
17
18 ## -*- texinfo -*-
19 ## @deftypefn {Function File} {} demo ('@var{name}',@var{n})
20 ##
21 ## Runs any examples associated with the function '@var{name}'.
22 ## Examples are stored in the script file, or in a file with the same
23 ## name but no extension somewhere on your path. To keep them separate
24 ## from the usual script code, all lines are prefixed by @code{%!}. Each
25 ## example is introduced by the keyword 'demo' flush left to the prefix,
26 ## with no intervening spaces. The remainder of the example can contain
27 ## arbitrary octave code. For example:
28 ##
29 ## @example
30 ## %!demo
31 ## %! t=0:0.01:2*pi; x = sin(t);
32 ## %! plot(t,x)
33 ## %! %-------------------------------------------------
34 ## %! % the figure window shows one cycle of a sine wave
35 ## @end example
36 ##
37 ## Note that the code is displayed before it is executed, so a simple
38 ## comment at the end suffices. It is generally not necessary to use
39 ## disp or printf within the demo.
40 ##
41 ## Demos are run in a function environment with no access to external
42 ## variables. This means that all demos in your function must use
43 ## separate initialization code. Alternatively, you can combine your
44 ## demos into one huge demo, with the code:
45 ##
46 ## @example
47 ## %! input("Press <enter> to continue: ","s");
48 ## @end example
49 ##
50 ## between the sections, but this is discouraged. Other techniques
51 ## include using multiple plots by saying figure between each, or
52 ## using subplot to put multiple plots in the same window.
53 ##
54 ## Also, since demo evaluates inside a function context, you cannot
55 ## define new functions inside a demo. Instead you will have to
56 ## use @code{eval(example('function',n))} to see them. Because eval only
57 ## evaluates one line, or one statement if the statement crosses
58 ## multiple lines, you must wrap your demo in "if 1 <demo stuff> endif"
59 ## with the 'if' on the same line as 'demo'. For example,
60 ##
61 ## @example
62 ## %!demo if 1
63 ## %! function y=f(x)
64 ## %! y=x;
65 ## %! endfunction
66 ## %! f(3)
67 ## %! endif
68 ## @end example
69 ##
70 ## @end deftypefn
71 ## @seealso{test, example}
72
73 ## TODO: modify subplot so that gnuplot_has_multiplot == 0 causes it to
74 ## TODO: use the current figure window but pause if not plotting in the
75 ## TODO: first subplot.
76
77 ## PKG_ADD: mark_as_command demo
78
79 function demo(name, n)
80
81 if (nargin < 1 || nargin > 2)
82 usage("demo('name') or demo('name, n)");
83 endif
84
85 if (nargin < 2)
86 n = 0;
87 endif
88
89 [code, idx] = test (name, 'grabdemo');
90 if (length(idx) == 0)
91 warning(["demo not available for ", name]);
92 return;
93 elseif (n >= length(idx))
94 warning(sprintf("only %d demos available for %s", length(idx)-1, name));
95 return;
96 endif
97
98
99 if (n > 0)
100 doidx = n;
101 else
102 doidx = [ 1 : length(idx)-1 ];
103 endif
104 for i=1:length(doidx)
105 ## Pause between demos
106 if (i > 1)
107 input("Press <enter> to continue: ","s");
108 endif
109
110 ## Process each demo without failing
111 try
112 block = code( idx(doidx(i)) : idx(doidx(i)+1) -1 );
113 ## Use an environment without variables
114 eval(["function __demo__()\n", block, "\nendfunction"]);
115 ## Display the code that will be executed before executing it
116 printf("%s example %d:%s\n\n", name, doidx(i), block);
117 __demo__;
118 catch
119 ## Let the programmer know which demo failed.
120 printf("%s example %d: failed\n%s", name, doidx(i), __error_text__);
121 end_try_catch
122 clear __demo__;
123 endfor
124
125 endfunction
126
127 %!demo
128 %! t=0:0.01:2*pi; x = sin(t);
129 %! plot(t,x)
130 %! %-------------------------------------------------
131 %! % the figure window shows one cycle of a sine wave