Mercurial > octave-nkf
annotate scripts/specfun/factorial.m @ 14062:5b49cafe0599 stable
Use non-negative, non-positive with hyphens in error messages.
* accumarray.m, polyfit.m, factorial.m, nchoosek.m, mcnemar_test.m, find.cc,
graphics.cc, sparse.cc: Use non-negative, non-positive with hyphens in error
messages for consistency with documentation.
| author | Rik <octave@nomad.inbox5.com> |
|---|---|
| date | Thu, 15 Dec 2011 22:03:03 -0800 |
| parents | 984359717d71 |
| children | 72c96de7a403 |
| rev | line source |
|---|---|
| 11523 | 1 ## Copyright (C) 2000-2011 Paul Kienzle |
| 5820 | 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. | |
| 5820 | 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/>. | |
| 5820 | 18 |
| 19 ## -*- texinfo -*- | |
| 20 ## @deftypefn {Function File} {} factorial (@var{n}) | |
|
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Rik <rdrider0-list@yahoo.com>
parents:
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diff
changeset
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21 ## Return the factorial of @var{n} where @var{n} is a positive integer. If |
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8c71a86c4bf4
Update section 17.5 (Utility Functions) of arith.txi
Rik <rdrider0-list@yahoo.com>
parents:
9141
diff
changeset
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22 ## @var{n} is a scalar, this is equivalent to @code{prod (1:@var{n})}. For |
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8c71a86c4bf4
Update section 17.5 (Utility Functions) of arith.txi
Rik <rdrider0-list@yahoo.com>
parents:
9141
diff
changeset
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23 ## vector or matrix arguments, return the factorial of each element in the |
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8c71a86c4bf4
Update section 17.5 (Utility Functions) of arith.txi
Rik <rdrider0-list@yahoo.com>
parents:
9141
diff
changeset
|
24 ## array. For non-integers see the generalized factorial function |
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8c71a86c4bf4
Update section 17.5 (Utility Functions) of arith.txi
Rik <rdrider0-list@yahoo.com>
parents:
9141
diff
changeset
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25 ## @code{gamma}. |
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8c71a86c4bf4
Update section 17.5 (Utility Functions) of arith.txi
Rik <rdrider0-list@yahoo.com>
parents:
9141
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changeset
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26 ## @seealso{prod, gamma} |
| 5820 | 27 ## @end deftypefn |
| 28 | |
| 29 function x = factorial (n) | |
| 6391 | 30 if (nargin != 1) |
| 31 print_usage (); | |
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Use common code idiom for checking whether a double value is an integer.
Rik <octave@nomad.inbox5.com>
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32 elseif (any (n(:) < 0 | n(:) != fix (n(:)))) |
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Use non-negative, non-positive with hyphens in error messages.
Rik <octave@nomad.inbox5.com>
parents:
13279
diff
changeset
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33 error ("factorial: N must all be non-negative integers"); |
| 5820 | 34 endif |
| 6532 | 35 x = round (gamma (n+1)); |
| 5820 | 36 endfunction |
| 6532 | 37 |
| 38 %!assert (factorial(5), prod(1:5)) | |
| 39 %!assert (factorial([1,2;3,4]), [1,2;6,24]) | |
| 6542 | 40 %!assert (factorial(70), exp(sum(log(1:70))), -128*eps) |
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14062
5b49cafe0599
Use non-negative, non-positive with hyphens in error messages.
Rik <octave@nomad.inbox5.com>
parents:
13279
diff
changeset
|
41 %!fail ('factorial(5.5)', "must all be non-negative integers") |
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5b49cafe0599
Use non-negative, non-positive with hyphens in error messages.
Rik <octave@nomad.inbox5.com>
parents:
13279
diff
changeset
|
42 %!fail ('factorial(-3)', "must all be non-negative integers") |