Mercurial > hg > octave-nkf
annotate scripts/specfun/beta.m @ 15144:9cc337ced51a
build: Update OCTAVE_UMFPACK_SEPARATE_SPLIT macro to look for SuiteSparse header file.
* acinclude.m4: Update OCTAVE_UMFPACK_SEPARATE_SPLIT macro to look for
SuiteSparse header file.
author | Rik <rik@octave.org> |
---|---|
date | Fri, 10 Aug 2012 12:56:15 -0700 |
parents | 67897baaa05f |
children | d63878346099 |
rev | line source |
---|---|
14138
72c96de7a403
maint: update copyright notices for 2012
John W. Eaton <jwe@octave.org>
parents:
11523
diff
changeset
|
1 ## Copyright (C) 1994-2012 John W. Eaton |
2313 | 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 | |
7016 | 7 ## the Free Software Foundation; either version 3 of the License, or (at |
8 ## your option) any later version. | |
2313 | 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 | |
7016 | 16 ## along with Octave; see the file COPYING. If not, see |
17 ## <http://www.gnu.org/licenses/>. | |
1026 | 18 |
3381 | 19 ## -*- texinfo -*- |
3321 | 20 ## @deftypefn {Mapping Function} {} beta (@var{a}, @var{b}) |
7601
8a939b217863
Treat negative values to lgamma and beta correctly
David Bateman <dbateman@free.fr>
parents:
7385
diff
changeset
|
21 ## For real inputs, return the Beta function, |
3321 | 22 ## @tex |
23 ## $$ | |
24 ## B (a, b) = {\Gamma (a) \Gamma (b) \over \Gamma (a + b)}. | |
25 ## $$ | |
26 ## @end tex | |
8517
81d6ab3ac93c
Allow documentation tobe built for other formats than tex and info
sh@sh-laptop
parents:
7601
diff
changeset
|
27 ## @ifnottex |
3426 | 28 ## |
3321 | 29 ## @example |
30 ## beta (a, b) = gamma (a) * gamma (b) / gamma (a + b). | |
31 ## @end example | |
10821
693e22af08ae
Grammarcheck documentation of m-files
Rik <octave@nomad.inbox5.com>
parents:
9211
diff
changeset
|
32 ## |
8517
81d6ab3ac93c
Allow documentation tobe built for other formats than tex and info
sh@sh-laptop
parents:
7601
diff
changeset
|
33 ## @end ifnottex |
14817
67897baaa05f
Adapt implementation of betaincinv to Octave.
Rik <octave@nomad.inbox5.com>
parents:
14363
diff
changeset
|
34 ## @seealso{betaln, betainc} |
3321 | 35 ## @end deftypefn |
2311 | 36 |
5428 | 37 ## Author: KH <Kurt.Hornik@wu-wien.ac.at> |
2312 | 38 ## Created: 13 June 1993 |
39 ## Adapted-By: jwe | |
40 | |
1026 | 41 function retval = beta (a, b) |
2325 | 42 |
1026 | 43 if (nargin != 2) |
6046 | 44 print_usage (); |
1026 | 45 endif |
46 | |
7601
8a939b217863
Treat negative values to lgamma and beta correctly
David Bateman <dbateman@free.fr>
parents:
7385
diff
changeset
|
47 if (any (size (a) != size (b)) && numel (a) != 1 && numel (b) != 1) |
10821
693e22af08ae
Grammarcheck documentation of m-files
Rik <octave@nomad.inbox5.com>
parents:
9211
diff
changeset
|
48 error ("beta: inputs A and B have inconsistent sizes"); |
7601
8a939b217863
Treat negative values to lgamma and beta correctly
David Bateman <dbateman@free.fr>
parents:
7385
diff
changeset
|
49 endif |
8a939b217863
Treat negative values to lgamma and beta correctly
David Bateman <dbateman@free.fr>
parents:
7385
diff
changeset
|
50 |
8a939b217863
Treat negative values to lgamma and beta correctly
David Bateman <dbateman@free.fr>
parents:
7385
diff
changeset
|
51 if (! isreal (a) || ! isreal (b)) |
10821
693e22af08ae
Grammarcheck documentation of m-files
Rik <octave@nomad.inbox5.com>
parents:
9211
diff
changeset
|
52 error ("beta: inputs A and B must be real"); |
7601
8a939b217863
Treat negative values to lgamma and beta correctly
David Bateman <dbateman@free.fr>
parents:
7385
diff
changeset
|
53 endif |
8a939b217863
Treat negative values to lgamma and beta correctly
David Bateman <dbateman@free.fr>
parents:
7385
diff
changeset
|
54 |
8a939b217863
Treat negative values to lgamma and beta correctly
David Bateman <dbateman@free.fr>
parents:
7385
diff
changeset
|
55 retval = real (exp (gammaln (a) + gammaln (b) - gammaln (a+b))); |
715 | 56 |
57 endfunction | |
7385 | 58 |
14363
f3d52523cde1
Use Octave coding conventions in all m-file %!test blocks
Rik <octave@nomad.inbox5.com>
parents:
14138
diff
changeset
|
59 |
7385 | 60 %!test |
14363
f3d52523cde1
Use Octave coding conventions in all m-file %!test blocks
Rik <octave@nomad.inbox5.com>
parents:
14138
diff
changeset
|
61 %! a = [1, 1.5, 2, 3]; |
f3d52523cde1
Use Octave coding conventions in all m-file %!test blocks
Rik <octave@nomad.inbox5.com>
parents:
14138
diff
changeset
|
62 %! b = [4, 3, 2, 1]; |
f3d52523cde1
Use Octave coding conventions in all m-file %!test blocks
Rik <octave@nomad.inbox5.com>
parents:
14138
diff
changeset
|
63 %! v1 = beta (a,b); |
f3d52523cde1
Use Octave coding conventions in all m-file %!test blocks
Rik <octave@nomad.inbox5.com>
parents:
14138
diff
changeset
|
64 %! v2 = beta (b,a); |
f3d52523cde1
Use Octave coding conventions in all m-file %!test blocks
Rik <octave@nomad.inbox5.com>
parents:
14138
diff
changeset
|
65 %! v3 = gamma (a).*gamma (b) ./ gamma (a+b); |
f3d52523cde1
Use Octave coding conventions in all m-file %!test blocks
Rik <octave@nomad.inbox5.com>
parents:
14138
diff
changeset
|
66 %! assert (v1, v2, sqrt (eps)); |
f3d52523cde1
Use Octave coding conventions in all m-file %!test blocks
Rik <octave@nomad.inbox5.com>
parents:
14138
diff
changeset
|
67 %! assert (v2, v3, sqrt (eps)); |
7385 | 68 |
14363
f3d52523cde1
Use Octave coding conventions in all m-file %!test blocks
Rik <octave@nomad.inbox5.com>
parents:
14138
diff
changeset
|
69 %!assert (beta (1, 1), 1) |
7601
8a939b217863
Treat negative values to lgamma and beta correctly
David Bateman <dbateman@free.fr>
parents:
7385
diff
changeset
|
70 |
8a939b217863
Treat negative values to lgamma and beta correctly
David Bateman <dbateman@free.fr>
parents:
7385
diff
changeset
|
71 %!test |
8a939b217863
Treat negative values to lgamma and beta correctly
David Bateman <dbateman@free.fr>
parents:
7385
diff
changeset
|
72 %! a = 2:10; |
8a939b217863
Treat negative values to lgamma and beta correctly
David Bateman <dbateman@free.fr>
parents:
7385
diff
changeset
|
73 %! tol = 10 * max (a) * eps; |
14363
f3d52523cde1
Use Octave coding conventions in all m-file %!test blocks
Rik <octave@nomad.inbox5.com>
parents:
14138
diff
changeset
|
74 %! assert (-a, beta (-1./a, 1), tol); |
f3d52523cde1
Use Octave coding conventions in all m-file %!test blocks
Rik <octave@nomad.inbox5.com>
parents:
14138
diff
changeset
|
75 %! assert (-a, beta (1, -1./a), tol); |
7601
8a939b217863
Treat negative values to lgamma and beta correctly
David Bateman <dbateman@free.fr>
parents:
7385
diff
changeset
|
76 |
8a939b217863
Treat negative values to lgamma and beta correctly
David Bateman <dbateman@free.fr>
parents:
7385
diff
changeset
|
77 %!test |
8a939b217863
Treat negative values to lgamma and beta correctly
David Bateman <dbateman@free.fr>
parents:
7385
diff
changeset
|
78 %! a = 0.25 + (0:5) * 0.5; |
8a939b217863
Treat negative values to lgamma and beta correctly
David Bateman <dbateman@free.fr>
parents:
7385
diff
changeset
|
79 %! tol = 10 * max (a) * eps; |
14363
f3d52523cde1
Use Octave coding conventions in all m-file %!test blocks
Rik <octave@nomad.inbox5.com>
parents:
14138
diff
changeset
|
80 %! assert (zeros (size (a)), beta (a, -a), tol); |
f3d52523cde1
Use Octave coding conventions in all m-file %!test blocks
Rik <octave@nomad.inbox5.com>
parents:
14138
diff
changeset
|
81 %! assert (zeros (size (a)), beta (-a, a), tol); |
f3d52523cde1
Use Octave coding conventions in all m-file %!test blocks
Rik <octave@nomad.inbox5.com>
parents:
14138
diff
changeset
|
82 |
f3d52523cde1
Use Octave coding conventions in all m-file %!test blocks
Rik <octave@nomad.inbox5.com>
parents:
14138
diff
changeset
|
83 %!error beta () |
f3d52523cde1
Use Octave coding conventions in all m-file %!test blocks
Rik <octave@nomad.inbox5.com>
parents:
14138
diff
changeset
|
84 %!error beta (1) |
f3d52523cde1
Use Octave coding conventions in all m-file %!test blocks
Rik <octave@nomad.inbox5.com>
parents:
14138
diff
changeset
|
85 |