Mercurial > hg > octave-nkf

annotate scripts/general/polyarea.m @ 20818:9d2023d1a63c

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
binoinv.m: Implement binary search algorithm for 28X performance increase (bug #34363). * binoinv.m: Call new functions scalar_binoinv or vector_binoinv to calculate binoinv. If there are still uncalculated values then call bin_search_binoinv to perform binary search for remaining values. Add more BIST tests. * binoinv.m (scalar_binoinv): New subfunction to calculate binoinv for scalar x. Stops when x > 1000. * binoinv.m (vector_binoinv): New subfunction to calculate binoinv for scalar x. Stops when x > 1000.
author Lachlan Andrew <lachlanbis@gmail.com>
date Sun, 11 Oct 2015 19:49:40 -0700
parents 7503499a252b
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
19898
4197fc428c7d maint: Update copyright notices for 2015.
John W. Eaton <jwe@octave.org>
parents: 17744
diff changeset
1 ## Copyright (C) 1999-2015 David M. Doolin
5837
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
2 ##
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
3 ## This file is part of Octave.
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
4 ##
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
5 ## Octave is free software; you can redistribute it and/or modify it
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
6 ## under the terms of the GNU General Public License as published by
7016
93c65f2a5668 [project @ 2007-10-12 06:40:56 by jwe]
jwe
parents: 7001
diff changeset
7 ## the Free Software Foundation; either version 3 of the License, or (at
93c65f2a5668 [project @ 2007-10-12 06:40:56 by jwe]
jwe
parents: 7001
diff changeset
8 ## your option) any later version.
5837
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
9 ##
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
10 ## Octave is distributed in the hope that it will be useful, but
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
11 ## WITHOUT ANY WARRANTY; without even the implied warranty of
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
12 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
13 ## General Public License for more details.
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
14 ##
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
15 ## You should have received a copy of the GNU General Public License
7016
93c65f2a5668 [project @ 2007-10-12 06:40:56 by jwe]
jwe
parents: 7001
diff changeset
16 ## along with Octave; see the file COPYING. If not, see
93c65f2a5668 [project @ 2007-10-12 06:40:56 by jwe]
jwe
parents: 7001
diff changeset
17 ## <http://www.gnu.org/licenses/>.
5837
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
18
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
19 ## -*- texinfo -*-
10793
be55736a0783 Grammarcheck the documentation from m-files.
Rik <octave@nomad.inbox5.com>
parents: 9245
diff changeset
20 ## @deftypefn {Function File} {} polyarea (@var{x}, @var{y})
5837
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
21 ## @deftypefnx {Function File} {} polyarea (@var{x}, @var{y}, @var{dim})
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
22 ##
20368
7503499a252b doc: Update docstrings to have one sentence summary as first line.
Rik <rik@octave.org>
parents: 19898
diff changeset
23 ## Determine area of a polygon by triangle method.
5837
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
24 ##
20368
7503499a252b doc: Update docstrings to have one sentence summary as first line.
Rik <rik@octave.org>
parents: 19898
diff changeset
25 ## The variables @var{x} and @var{y} define the vertex pairs, and must
7503499a252b doc: Update docstrings to have one sentence summary as first line.
Rik <rik@octave.org>
parents: 19898
diff changeset
26 ## therefore have the same shape. They can be either vectors or arrays. If
7503499a252b doc: Update docstrings to have one sentence summary as first line.
Rik <rik@octave.org>
parents: 19898
diff changeset
27 ## they are arrays then the columns of @var{x} and @var{y} are treated
7503499a252b doc: Update docstrings to have one sentence summary as first line.
Rik <rik@octave.org>
parents: 19898
diff changeset
28 ## separately and an area returned for each.
7503499a252b doc: Update docstrings to have one sentence summary as first line.
Rik <rik@octave.org>
parents: 19898
diff changeset
29 ##
7503499a252b doc: Update docstrings to have one sentence summary as first line.
Rik <rik@octave.org>
parents: 19898
diff changeset
30 ## If the optional @var{dim} argument is given, then @code{polyarea} works
7503499a252b doc: Update docstrings to have one sentence summary as first line.
Rik <rik@octave.org>
parents: 19898
diff changeset
31 ## along this dimension of the arrays @var{x} and @var{y}.
5837
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
32 ##
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
33 ## @end deftypefn
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
34
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
35 ## todo: Add moments for centroid, etc.
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
36 ##
11587
c792872f8942 all script files: untabify and strip trailing whitespace
John W. Eaton <jwe@octave.org>
parents: 11523
diff changeset
37 ## bugs and limitations:
5837
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
38 ## Probably ought to be an optional check to make sure that
11587
c792872f8942 all script files: untabify and strip trailing whitespace
John W. Eaton <jwe@octave.org>
parents: 11523
diff changeset
39 ## traversing the vertices doesn't make any sides cross
c792872f8942 all script files: untabify and strip trailing whitespace
John W. Eaton <jwe@octave.org>
parents: 11523
diff changeset
40 ## (Is simple closed curve the technical definition of this?).
5837
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
41
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
42 ## Author: David M. Doolin <doolin@ce.berkeley.edu>
5838
376e02b2ce70 [project @ 2006-06-01 20:23:53 by jwe]
jwe
parents: 5837
diff changeset
43 ## Date: 1999-04-14
11587
c792872f8942 all script files: untabify and strip trailing whitespace
John W. Eaton <jwe@octave.org>
parents: 11523
diff changeset
44 ## Modified-by:
5837
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
45 ## 2000-01-15 Paul Kienzle <pkienzle@kienzle.powernet.co.uk>
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
46 ## * use matlab compatible interface
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
47 ## * return absolute value of area so traversal order doesn't matter
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
48 ## 2005-10-13 Torsten Finke
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
49 ## * optimization saving half the sums and multiplies
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
50
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
51 function a = polyarea (x, y, dim)
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
52 if (nargin != 2 && nargin != 3)
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
53 print_usage ();
6157
045038e0108a [project @ 2006-11-13 22:22:53 by jwe]
jwe
parents: 5838
diff changeset
54 elseif (size_equal (x, y))
5837
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
55 if (nargin == 2)
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
56 a = abs (sum (x .* (shift (y, -1) - shift (y, 1)))) / 2;
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
57 else
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
58 a = abs (sum (x .* (shift (y, -1, dim) - shift (y, 1, dim)), dim)) / 2;
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
59 endif
5838
376e02b2ce70 [project @ 2006-06-01 20:23:53 by jwe]
jwe
parents: 5837
diff changeset
60 else
11472
1740012184f9 Use uppercase for variable names in error() strings to match Info documentation. Only m-files done.
Rik <octave@nomad.inbox5.com>
parents: 10793
diff changeset
61 error ("polyarea: X and Y must have the same shape");
5837
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
62 endif
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
63 endfunction
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
64
14363
f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks
Rik <octave@nomad.inbox5.com>
parents: 14138
diff changeset
65
5837
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
66 %!shared x, y
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
67 %! x = [1;1;3;3;1];
55404f3b0da1 [project @ 2006-06-01 19:05:31 by jwe]
jwe
parents:
diff changeset
68 %! y = [1;3;3;1;1];
14363
f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks
Rik <octave@nomad.inbox5.com>
parents: 14138
diff changeset
69 %!assert (polyarea (x,y), 4, eps)
f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks
Rik <octave@nomad.inbox5.com>
parents: 14138
diff changeset
70 %!assert (polyarea ([x,x],[y,y]), [4,4], eps)
f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks
Rik <octave@nomad.inbox5.com>
parents: 14138
diff changeset
71 %!assert (polyarea ([x,x],[y,y],1), [4,4], eps)
f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks
Rik <octave@nomad.inbox5.com>
parents: 14138
diff changeset
72 %!assert (polyarea ([x,x]',[y,y]',2), [4;4], eps)
f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks
Rik <octave@nomad.inbox5.com>
parents: 14138
diff changeset
73