octave: scripts/specfun/nchoosek.m annotate

annotate scripts/specfun/nchoosek.m @ 30218:750de16fd35c

nchoosek.m: Fix algorithm for even K in cset f5aba4d7e651 (bug #61191). * nchoosek.m: When doing pairwise multiplication, flip the second range so that an even number is always multiplied by an odd number.

author	Rik <rik@octave.org>
date	Wed, 29 Sep 2021 09:57:01 -0700
parents	f5aba4d7e651
children	363fb10055df

rev	line source
27923 bd51beb6205e update formatting of copyright notices John W. Eaton <jwe@octave.org> parents: 27919 diff changeset	1 ########################################################################
bd51beb6205e update formatting of copyright notices John W. Eaton <jwe@octave.org> parents: 27919 diff changeset	2 ##
29358 0a5b15007766 update Octave Project Developers copyright for the new year John W. Eaton <jwe@octave.org> parents: 27985 diff changeset	3 ## Copyright (C) 2001-2021 The Octave Project Developers
27918 b442ec6dda5c use centralized file for copyright info for individual contributors John W. Eaton <jwe@octave.org> parents: 26376 diff changeset	4 ##
27923 bd51beb6205e update formatting of copyright notices John W. Eaton <jwe@octave.org> parents: 27919 diff changeset	5 ## See the file COPYRIGHT.md in the top-level directory of this
bd51beb6205e update formatting of copyright notices John W. Eaton <jwe@octave.org> parents: 27919 diff changeset	6 ## distribution or <https://octave.org/copyright/>.
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	7 ##
1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	8 ## This file is part of Octave.
1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	9 ##
24534 194eb4bd202b maint: Update punctuation for GPL v3 license text. Rik <rik@octave.org> parents: 23220 diff changeset	10 ## Octave is free software: you can redistribute it and/or modify it
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	11 ## under the terms of the GNU General Public License as published by
24534 194eb4bd202b maint: Update punctuation for GPL v3 license text. Rik <rik@octave.org> parents: 23220 diff changeset	12 ## the Free Software Foundation, either version 3 of the License, or
22755 3a2b891d0b33 maint: Standardize Copyright formatting. Rik <rik@octave.org> parents: 22323 diff changeset	13 ## (at your option) any later version.
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	14 ##
1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	15 ## Octave is distributed in the hope that it will be useful, but
1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	16 ## WITHOUT ANY WARRANTY; without even the implied warranty of
22755 3a2b891d0b33 maint: Standardize Copyright formatting. Rik <rik@octave.org> parents: 22323 diff changeset	17 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
3a2b891d0b33 maint: Standardize Copyright formatting. Rik <rik@octave.org> parents: 22323 diff changeset	18 ## GNU General Public License for more details.
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	19 ##
1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	20 ## 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: 6754 diff changeset	21 ## along with Octave; see the file COPYING. If not, see
24534 194eb4bd202b maint: Update punctuation for GPL v3 license text. Rik <rik@octave.org> parents: 23220 diff changeset	22 ## <https://www.gnu.org/licenses/>.
27923 bd51beb6205e update formatting of copyright notices John W. Eaton <jwe@octave.org> parents: 27919 diff changeset	23 ##
bd51beb6205e update formatting of copyright notices John W. Eaton <jwe@octave.org> parents: 27919 diff changeset	24 ########################################################################
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	25
1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	26 ## -- texinfo --
20852 516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files. Rik <rik@octave.org> parents: 19833 diff changeset	27 ## @deftypefn {} {@var{c} =} nchoosek (@var{n}, @var{k})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files. Rik <rik@octave.org> parents: 19833 diff changeset	28 ## @deftypefnx {} {@var{c} =} nchoosek (@var{set}, @var{k})
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	29 ##
19059 83b88e20e9c1 nchoosek.m: Overhaul function. Rik <rik@octave.org> parents: 18795 diff changeset	30 ## Compute the binomial coefficient of @var{n} or list all possible
83b88e20e9c1 nchoosek.m: Overhaul function. Rik <rik@octave.org> parents: 18795 diff changeset	31 ## combinations of a @var{set} of items.
14090 281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	32 ##
281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	33 ## If @var{n} is a scalar then calculate the binomial coefficient
281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	34 ## of @var{n} and @var{k} which is defined as
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	35 ## @tex
1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	36 ## $$
1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	37 ## {n \choose k} = {n (n-1) (n-2) \cdots (n-k+1) \over k!}
6754 451b346d8c2f [project @ 2007-06-25 17:31:46 by jwe] jwe parents: 6575 diff changeset	38 ## = {n! \over k! (n-k)!}
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	39 ## $$
1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	40 ## @end tex
8517 81d6ab3ac93c Allow documentation tobe built for other formats than tex and info sh@sh-laptop parents: 8506 diff changeset	41 ## @ifnottex
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	42 ##
1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	43 ## @example
1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	44 ## @group
1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	45 ## / \
9051 1bf0ce0930be Grammar check TexInfo in all .m files Rik <rdrider0-list@yahoo.com> parents: 8920 diff changeset	46 ## \| n \| n (n-1) (n-2) @dots{} (n-k+1) n!
6754 451b346d8c2f [project @ 2007-06-25 17:31:46 by jwe] jwe parents: 6575 diff changeset	47 ## \| \| = ------------------------- = ---------
451b346d8c2f [project @ 2007-06-25 17:31:46 by jwe] jwe parents: 6575 diff changeset	48 ## \| k \| k! k! (n-k)!
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	49 ## \ /
1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	50 ## @end group
1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	51 ## @end example
10821 693e22af08ae Grammarcheck documentation of m-files Rik <octave@nomad.inbox5.com> parents: 10800 diff changeset	52 ##
8517 81d6ab3ac93c Allow documentation tobe built for other formats than tex and info sh@sh-laptop parents: 8506 diff changeset	53 ## @end ifnottex
14090 281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	54 ## @noindent
281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	55 ## This is the number of combinations of @var{n} items taken in groups of
281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	56 ## size @var{k}.
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	57 ##
14093 050bc580cb60 doc: Various docstring improvements before 3.6.0 release. Rik <octave@nomad.inbox5.com> parents: 14090 diff changeset	58 ## If the first argument is a vector, @var{set}, then generate all
050bc580cb60 doc: Various docstring improvements before 3.6.0 release. Rik <octave@nomad.inbox5.com> parents: 14090 diff changeset	59 ## combinations of the elements of @var{set}, taken @var{k} at a time, with
050bc580cb60 doc: Various docstring improvements before 3.6.0 release. Rik <octave@nomad.inbox5.com> parents: 14090 diff changeset	60 ## one row per combination. The result @var{c} has @var{k} columns and
14090 281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	61 ## @w{@code{nchoosek (length (@var{set}), @var{k})}} rows.
281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	62 ##
281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	63 ## For example:
281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	64 ##
281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	65 ## How many ways can three items be grouped into pairs?
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	66 ##
14090 281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	67 ## @example
281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	68 ## @group
281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	69 ## nchoosek (3, 2)
281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	70 ## @result{} 3
281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	71 ## @end group
281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	72 ## @end example
281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	73 ##
281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	74 ## What are the possible pairs?
8404 868149aac690 nchoosek checks, warning, corner cases and tests Francesco Potortì <pot@gnu.org> parents: 8391 diff changeset	75 ##
14090 281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	76 ## @example
281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	77 ## @group
281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	78 ## nchoosek (1:3, 2)
281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	79 ## @result{} 1 2
281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	80 ## 1 3
281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	81 ## 2 3
281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	82 ## @end group
281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	83 ## @end example
281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	84 ##
19059 83b88e20e9c1 nchoosek.m: Overhaul function. Rik <rik@octave.org> parents: 18795 diff changeset	85 ## Programming Note: When calculating the binomial coefficient @code{nchoosek}
83b88e20e9c1 nchoosek.m: Overhaul function. Rik <rik@octave.org> parents: 18795 diff changeset	86 ## works only for non-negative, integer arguments. Use @code{bincoeff} for
83b88e20e9c1 nchoosek.m: Overhaul function. Rik <rik@octave.org> parents: 18795 diff changeset	87 ## non-integer and negative scalar arguments, or for computing many binomial
83b88e20e9c1 nchoosek.m: Overhaul function. Rik <rik@octave.org> parents: 18795 diff changeset	88 ## coefficients at once with vector inputs for @var{n} or @var{k}.
14090 281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	89 ##
281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	90 ## @seealso{bincoeff, perms}
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	91 ## @end deftypefn
1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	92
19059 83b88e20e9c1 nchoosek.m: Overhaul function. Rik <rik@octave.org> parents: 18795 diff changeset	93 function C = nchoosek (v, k)
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	94
30205 23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	95 if (nargin != 2)
6316 a3a2580435c2 [project @ 2007-02-16 07:23:49 by jwe] jwe parents: 5827 diff changeset	96 print_usage ();
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	97 endif
30205 23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	98
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	99 if (! isvector (v))
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	100 error ("nchoosek: first argument must be a scalar or a vector");
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	101 endif
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	102 if (! (isreal (k) && isscalar (k) && k >= 0 && k == fix (k)))
19059 83b88e20e9c1 nchoosek.m: Overhaul function. Rik <rik@octave.org> parents: 18795 diff changeset	103 error ("nchoosek: K must be an integer >= 0");
30205 23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	104 endif
30206 aaee7b170cb1 nchoosek.m: Allow struct inputs (bug #61119) Rik <rik@octave.org> parents: 30205 diff changeset	105 if (isscalar (v))
aaee7b170cb1 nchoosek.m: Allow struct inputs (bug #61119) Rik <rik@octave.org> parents: 30205 diff changeset	106 if (isnumeric (v) && (iscomplex (v) \|\| v < k \|\| v < 0 \|\| v != fix (v)))
aaee7b170cb1 nchoosek.m: Allow struct inputs (bug #61119) Rik <rik@octave.org> parents: 30205 diff changeset	107 error ("nchoosek: N must be a non-negative integer >= K");
aaee7b170cb1 nchoosek.m: Allow struct inputs (bug #61119) Rik <rik@octave.org> parents: 30205 diff changeset	108 endif
8404 868149aac690 nchoosek checks, warning, corner cases and tests Francesco Potortì <pot@gnu.org> parents: 8391 diff changeset	109 endif
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	110
30205 23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	111 n = numel (v);
6318 bae85c1e0e2a [project @ 2007-02-16 08:15:25 by jwe] jwe parents: 6316 diff changeset	112
30205 23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	113 if (n == 1 && isnumeric (v))
30217 f5aba4d7e651 nchoosek.m: New algorithm with more precision when N, K are scalars (bug #61199) Rik <rik@octave.org> parents: 30209 diff changeset	114 ## Improve precision over direct call to prod().
f5aba4d7e651 nchoosek.m: New algorithm with more precision when N, K are scalars (bug #61199) Rik <rik@octave.org> parents: 30209 diff changeset	115 ## Steps: 1) Make a list of integers for numerator and denominator,
f5aba4d7e651 nchoosek.m: New algorithm with more precision when N, K are scalars (bug #61199) Rik <rik@octave.org> parents: 30209 diff changeset	116 ## 2) filter out common factors, 3) multiply what remains.
8506 bc982528de11 comment style fixes John W. Eaton <jwe@octave.org> parents: 8404 diff changeset	117 k = min (k, v-k);
30217 f5aba4d7e651 nchoosek.m: New algorithm with more precision when N, K are scalars (bug #61199) Rik <rik@octave.org> parents: 30209 diff changeset	118
f5aba4d7e651 nchoosek.m: New algorithm with more precision when N, K are scalars (bug #61199) Rik <rik@octave.org> parents: 30209 diff changeset	119 ## For a ~25% performance boost, multiply values pairwise so there
f5aba4d7e651 nchoosek.m: New algorithm with more precision when N, K are scalars (bug #61199) Rik <rik@octave.org> parents: 30209 diff changeset	120 ## are fewer elements in do/until loop which is the slow part.
f5aba4d7e651 nchoosek.m: New algorithm with more precision when N, K are scalars (bug #61199) Rik <rik@octave.org> parents: 30209 diff changeset	121 ## Since Odd*Even is guaranteed to be Even, also take out a factor
f5aba4d7e651 nchoosek.m: New algorithm with more precision when N, K are scalars (bug #61199) Rik <rik@octave.org> parents: 30209 diff changeset	122 ## of 2 from numerator and denominator.
f5aba4d7e651 nchoosek.m: New algorithm with more precision when N, K are scalars (bug #61199) Rik <rik@octave.org> parents: 30209 diff changeset	123 if (rem (k, 2)) # k is odd
f5aba4d7e651 nchoosek.m: New algorithm with more precision when N, K are scalars (bug #61199) Rik <rik@octave.org> parents: 30209 diff changeset	124 numer = [(v-k+1:v-(k+1)/2) .* (v-1:-1:v-(k-1)/2) / 2, v];
f5aba4d7e651 nchoosek.m: New algorithm with more precision when N, K are scalars (bug #61199) Rik <rik@octave.org> parents: 30209 diff changeset	125 denom = [(1:k/2) .* (k-1:-1:(k+1)/2) / 2, k];
f5aba4d7e651 nchoosek.m: New algorithm with more precision when N, K are scalars (bug #61199) Rik <rik@octave.org> parents: 30209 diff changeset	126 else # k is even
30218 750de16fd35c nchoosek.m: Fix algorithm for even K in cset f5aba4d7e651 (bug #61191). Rik <rik@octave.org> parents: 30217 diff changeset	127 numer = (v-k+1:v-k/2) .* (v:-1:v-k/2+1) / 2;
750de16fd35c nchoosek.m: Fix algorithm for even K in cset f5aba4d7e651 (bug #61191). Rik <rik@octave.org> parents: 30217 diff changeset	128 denom = (1:k/2) .* (k:-1:k/2+1) / 2;
750de16fd35c nchoosek.m: Fix algorithm for even K in cset f5aba4d7e651 (bug #61191). Rik <rik@octave.org> parents: 30217 diff changeset	129 endif
30217 f5aba4d7e651 nchoosek.m: New algorithm with more precision when N, K are scalars (bug #61199) Rik <rik@octave.org> parents: 30209 diff changeset	130
f5aba4d7e651 nchoosek.m: New algorithm with more precision when N, K are scalars (bug #61199) Rik <rik@octave.org> parents: 30209 diff changeset	131 # Remove common factors from numerator and denominator
f5aba4d7e651 nchoosek.m: New algorithm with more precision when N, K are scalars (bug #61199) Rik <rik@octave.org> parents: 30209 diff changeset	132 do
f5aba4d7e651 nchoosek.m: New algorithm with more precision when N, K are scalars (bug #61199) Rik <rik@octave.org> parents: 30209 diff changeset	133 for i = numel (denom):-1:1
f5aba4d7e651 nchoosek.m: New algorithm with more precision when N, K are scalars (bug #61199) Rik <rik@octave.org> parents: 30209 diff changeset	134 factors = gcd (denom(i), numer);
f5aba4d7e651 nchoosek.m: New algorithm with more precision when N, K are scalars (bug #61199) Rik <rik@octave.org> parents: 30209 diff changeset	135 [f, j] = max (factors);
f5aba4d7e651 nchoosek.m: New algorithm with more precision when N, K are scalars (bug #61199) Rik <rik@octave.org> parents: 30209 diff changeset	136 denom(i) /= f;
f5aba4d7e651 nchoosek.m: New algorithm with more precision when N, K are scalars (bug #61199) Rik <rik@octave.org> parents: 30209 diff changeset	137 numer(j) /= f;
f5aba4d7e651 nchoosek.m: New algorithm with more precision when N, K are scalars (bug #61199) Rik <rik@octave.org> parents: 30209 diff changeset	138 endfor
f5aba4d7e651 nchoosek.m: New algorithm with more precision when N, K are scalars (bug #61199) Rik <rik@octave.org> parents: 30209 diff changeset	139 denom = denom(denom > 1);
f5aba4d7e651 nchoosek.m: New algorithm with more precision when N, K are scalars (bug #61199) Rik <rik@octave.org> parents: 30209 diff changeset	140 numer = numer(numer > 1);
f5aba4d7e651 nchoosek.m: New algorithm with more precision when N, K are scalars (bug #61199) Rik <rik@octave.org> parents: 30209 diff changeset	141 until (isempty (denom))
f5aba4d7e651 nchoosek.m: New algorithm with more precision when N, K are scalars (bug #61199) Rik <rik@octave.org> parents: 30209 diff changeset	142
f5aba4d7e651 nchoosek.m: New algorithm with more precision when N, K are scalars (bug #61199) Rik <rik@octave.org> parents: 30209 diff changeset	143 C = prod (numer);
f5aba4d7e651 nchoosek.m: New algorithm with more precision when N, K are scalars (bug #61199) Rik <rik@octave.org> parents: 30209 diff changeset	144 if (C > flintmax)
19059 83b88e20e9c1 nchoosek.m: Overhaul function. Rik <rik@octave.org> parents: 18795 diff changeset	145 warning ("nchoosek: possible loss of precision");
8391 343f0fbca6eb implement nchoosek without recursion Jaroslav Hajek <highegg@gmail.com> parents: 8361 diff changeset	146 endif
8404 868149aac690 nchoosek checks, warning, corner cases and tests Francesco Potortì <pot@gnu.org> parents: 8391 diff changeset	147 elseif (k == 0)
30205 23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	148 C = v(zeros (1, 0)); # Return 1x0 object for Matlab compatibility
6318 bae85c1e0e2a [project @ 2007-02-16 08:15:25 by jwe] jwe parents: 6316 diff changeset	149 elseif (k == 1)
19059 83b88e20e9c1 nchoosek.m: Overhaul function. Rik <rik@octave.org> parents: 18795 diff changeset	150 C = v(:);
8404 868149aac690 nchoosek checks, warning, corner cases and tests Francesco Potortì <pot@gnu.org> parents: 8391 diff changeset	151 elseif (k == n)
19059 83b88e20e9c1 nchoosek.m: Overhaul function. Rik <rik@octave.org> parents: 18795 diff changeset	152 C = v(:).';
8391 343f0fbca6eb implement nchoosek without recursion Jaroslav Hajek <highegg@gmail.com> parents: 8361 diff changeset	153 elseif (k > n)
30205 23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	154 C = v(zeros (0, k)); # return 0xk object for Matlab compatibility
10800 23b3ae008f5e optimize nchoosek Jaroslav Hajek <highegg@gmail.com> parents: 10549 diff changeset	155 elseif (k == 2)
23b3ae008f5e optimize nchoosek Jaroslav Hajek <highegg@gmail.com> parents: 10549 diff changeset	156 ## Can do it without transpose.
30209 54774a713d7c nchoosek.m: Improve struct input handling for k<n (bug #61119) Nicholas R. Jankowski <jankowskin@asme.org> parents: 30206 diff changeset	157 x = repelem (v(1:n-1), [n-1:-1:1]).';
10800 23b3ae008f5e optimize nchoosek Jaroslav Hajek <highegg@gmail.com> parents: 10549 diff changeset	158 y = cat (1, cellslices (v(:), 2:n, n*ones (1, n-1)){:});
19059 83b88e20e9c1 nchoosek.m: Overhaul function. Rik <rik@octave.org> parents: 18795 diff changeset	159 C = [x, y];
10800 23b3ae008f5e optimize nchoosek Jaroslav Hajek <highegg@gmail.com> parents: 10549 diff changeset	160 elseif (k < n)
23b3ae008f5e optimize nchoosek Jaroslav Hajek <highegg@gmail.com> parents: 10549 diff changeset	161 v = v(:).';
19059 83b88e20e9c1 nchoosek.m: Overhaul function. Rik <rik@octave.org> parents: 18795 diff changeset	162 C = v(k:n);
10800 23b3ae008f5e optimize nchoosek Jaroslav Hajek <highegg@gmail.com> parents: 10549 diff changeset	163 l = 1:n-k+1;
23b3ae008f5e optimize nchoosek Jaroslav Hajek <highegg@gmail.com> parents: 10549 diff changeset	164 for j = 2:k
19059 83b88e20e9c1 nchoosek.m: Overhaul function. Rik <rik@octave.org> parents: 18795 diff changeset	165 c = columns (C);
83b88e20e9c1 nchoosek.m: Overhaul function. Rik <rik@octave.org> parents: 18795 diff changeset	166 cA = cellslices (C, l, c*ones (1, n-k+1), 2);
10800 23b3ae008f5e optimize nchoosek Jaroslav Hajek <highegg@gmail.com> parents: 10549 diff changeset	167 l = c-l+1;
30209 54774a713d7c nchoosek.m: Improve struct input handling for k<n (bug #61119) Nicholas R. Jankowski <jankowskin@asme.org> parents: 30206 diff changeset	168 b = repelem (v(k-j+1:n-j+1), l);
19059 83b88e20e9c1 nchoosek.m: Overhaul function. Rik <rik@octave.org> parents: 18795 diff changeset	169 C = [b; cA{:}];
10800 23b3ae008f5e optimize nchoosek Jaroslav Hajek <highegg@gmail.com> parents: 10549 diff changeset	170 l = cumsum (l);
23b3ae008f5e optimize nchoosek Jaroslav Hajek <highegg@gmail.com> parents: 10549 diff changeset	171 l = [1, 1 + l(1:n-k)];
8391 343f0fbca6eb implement nchoosek without recursion Jaroslav Hajek <highegg@gmail.com> parents: 8361 diff changeset	172 endfor
19059 83b88e20e9c1 nchoosek.m: Overhaul function. Rik <rik@octave.org> parents: 18795 diff changeset	173 C = C.';
6318 bae85c1e0e2a [project @ 2007-02-16 08:15:25 by jwe] jwe parents: 6316 diff changeset	174 endif
19059 83b88e20e9c1 nchoosek.m: Overhaul function. Rik <rik@octave.org> parents: 18795 diff changeset	175
8361 cf620941af1a Set max_recursion_depth and use a subfunction in nchoosek Francesco Potortì <pot@gnu.org> parents: 7017 diff changeset	176 endfunction
6318 bae85c1e0e2a [project @ 2007-02-16 08:15:25 by jwe] jwe parents: 6316 diff changeset	177
14090 281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	178
30205 23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	179 %!assert (nchoosek (80, 10), bincoeff (80, 10))
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	180 %!assert (nchoosek (1:5, 3),
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	181 %! [1:3;1,2,4;1,2,5;1,3,4;1,3,5;1,4,5;2:4;2,3,5;2,4,5;3:5])
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	182
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	183 # Test basic behavior for various input types
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	184 %!assert (nchoosek ('a':'b', 2), 'ab')
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	185 %!assert (nchoosek ("a":"b", 2), "ab")
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	186 %!assert (nchoosek ({1,2}, 2), {1,2})
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	187 %!test
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	188 %! s(1).a = 1;
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	189 %! s(2).a = 2;
30209 54774a713d7c nchoosek.m: Improve struct input handling for k<n (bug #61119) Nicholas R. Jankowski <jankowskin@asme.org> parents: 30206 diff changeset	190 %! assert (nchoosek (s, 1), s(:));
54774a713d7c nchoosek.m: Improve struct input handling for k<n (bug #61119) Nicholas R. Jankowski <jankowskin@asme.org> parents: 30206 diff changeset	191 %! assert (nchoosek (s, 2), s);
30205 23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	192
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	193 # Verify Matlab compatibility of return sizes & types
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	194 %!test
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	195 %! x = nchoosek (1:2, 0);
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	196 %! assert (size (x), [1, 0]);
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	197 %! assert (isa (x, "double"));
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	198 %! x = nchoosek (1:2, 3);
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	199 %! assert (size (x), [0, 3]);
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	200 %! assert (isa (x, "double"));
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	201
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	202 %!test
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	203 %! x = nchoosek (single (1:2), 0);
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	204 %! assert (size (x), [1, 0]);
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	205 %! assert (isa (x, "single"));
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	206 %! x = nchoosek (single (1:2), 3);
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	207 %! assert (size (x), [0, 3]);
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	208 %! assert (isa (x, "single"));
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	209
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	210 %!test
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	211 %! x = nchoosek ('a':'b', 0);
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	212 %! assert (size (x), [1, 0]);
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	213 %! assert (is_sq_string (x));
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	214 %! x = nchoosek ('a':'b', 3);
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	215 %! assert (size (x), [0, 3]);
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	216 %! assert (is_sq_string (x));
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	217
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	218 %!test
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	219 %! x = nchoosek ("a":"b", 0);
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	220 %! assert (size (x), [1, 0]);
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	221 %! assert (is_dq_string (x));
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	222 %! x = nchoosek ("a":"b", 3);
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	223 %! assert (size (x), [0, 3]);
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	224 %! assert (is_dq_string (x));
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	225
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	226 %!test
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	227 %! x = nchoosek (uint8(1):uint8(2), 0);
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	228 %! assert (size (x), [1, 0]);
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	229 %! assert (isa (x, "uint8"));
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	230 %! x = nchoosek (uint8(1):uint8(2), 3);
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	231 %! assert (size (x), [0, 3]);
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	232 %! assert (isa (x, "uint8"));
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	233
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	234 %!test
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	235 %! x = nchoosek ({1, 2}, 0);
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	236 %! assert (size (x), [1, 0]);
30206 aaee7b170cb1 nchoosek.m: Allow struct inputs (bug #61119) Rik <rik@octave.org> parents: 30205 diff changeset	237 %! assert (iscell (x));
30205 23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	238 %! x = nchoosek ({1, 2}, 3);
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	239 %! assert (size (x), [0, 3]);
30206 aaee7b170cb1 nchoosek.m: Allow struct inputs (bug #61119) Rik <rik@octave.org> parents: 30205 diff changeset	240 %! assert (iscell (x));
aaee7b170cb1 nchoosek.m: Allow struct inputs (bug #61119) Rik <rik@octave.org> parents: 30205 diff changeset	241
aaee7b170cb1 nchoosek.m: Allow struct inputs (bug #61119) Rik <rik@octave.org> parents: 30205 diff changeset	242 %!test
aaee7b170cb1 nchoosek.m: Allow struct inputs (bug #61119) Rik <rik@octave.org> parents: 30205 diff changeset	243 %! s.a = [1 2 3];
aaee7b170cb1 nchoosek.m: Allow struct inputs (bug #61119) Rik <rik@octave.org> parents: 30205 diff changeset	244 %! s.b = [4 5 6];
aaee7b170cb1 nchoosek.m: Allow struct inputs (bug #61119) Rik <rik@octave.org> parents: 30205 diff changeset	245 %! x = nchoosek (s, 0);
aaee7b170cb1 nchoosek.m: Allow struct inputs (bug #61119) Rik <rik@octave.org> parents: 30205 diff changeset	246 %! assert (size (x), [1, 0]);
aaee7b170cb1 nchoosek.m: Allow struct inputs (bug #61119) Rik <rik@octave.org> parents: 30205 diff changeset	247 %! assert (isstruct (x));
aaee7b170cb1 nchoosek.m: Allow struct inputs (bug #61119) Rik <rik@octave.org> parents: 30205 diff changeset	248 %! assert (fieldnames (x), {"a"; "b"});
aaee7b170cb1 nchoosek.m: Allow struct inputs (bug #61119) Rik <rik@octave.org> parents: 30205 diff changeset	249 %! x = nchoosek (s, 3);
aaee7b170cb1 nchoosek.m: Allow struct inputs (bug #61119) Rik <rik@octave.org> parents: 30205 diff changeset	250 %! assert (size (x), [0, 3]);
aaee7b170cb1 nchoosek.m: Allow struct inputs (bug #61119) Rik <rik@octave.org> parents: 30205 diff changeset	251 %! assert (isstruct (x));
aaee7b170cb1 nchoosek.m: Allow struct inputs (bug #61119) Rik <rik@octave.org> parents: 30205 diff changeset	252 %! assert (fieldnames (x), {"a"; "b"});
aaee7b170cb1 nchoosek.m: Allow struct inputs (bug #61119) Rik <rik@octave.org> parents: 30205 diff changeset	253
aaee7b170cb1 nchoosek.m: Allow struct inputs (bug #61119) Rik <rik@octave.org> parents: 30205 diff changeset	254 %!test
aaee7b170cb1 nchoosek.m: Allow struct inputs (bug #61119) Rik <rik@octave.org> parents: 30205 diff changeset	255 %! s.a = [1 2 3];
aaee7b170cb1 nchoosek.m: Allow struct inputs (bug #61119) Rik <rik@octave.org> parents: 30205 diff changeset	256 %! s.b = [4 5 6];
aaee7b170cb1 nchoosek.m: Allow struct inputs (bug #61119) Rik <rik@octave.org> parents: 30205 diff changeset	257 %! s(2).a = 1; # make s a struct array rather than scalar struct
30209 54774a713d7c nchoosek.m: Improve struct input handling for k<n (bug #61119) Nicholas R. Jankowski <jankowskin@asme.org> parents: 30206 diff changeset	258 %! s(3).b = 2; # make s at least three elements for k == 2 test below
30206 aaee7b170cb1 nchoosek.m: Allow struct inputs (bug #61119) Rik <rik@octave.org> parents: 30205 diff changeset	259 %! x = nchoosek (s, 0);
aaee7b170cb1 nchoosek.m: Allow struct inputs (bug #61119) Rik <rik@octave.org> parents: 30205 diff changeset	260 %! assert (size (x), [1, 0]);
aaee7b170cb1 nchoosek.m: Allow struct inputs (bug #61119) Rik <rik@octave.org> parents: 30205 diff changeset	261 %! assert (isstruct (x));
aaee7b170cb1 nchoosek.m: Allow struct inputs (bug #61119) Rik <rik@octave.org> parents: 30205 diff changeset	262 %! assert (fieldnames (x), {"a"; "b"});
30209 54774a713d7c nchoosek.m: Improve struct input handling for k<n (bug #61119) Nicholas R. Jankowski <jankowskin@asme.org> parents: 30206 diff changeset	263 %! x = nchoosek (s, 2);
54774a713d7c nchoosek.m: Improve struct input handling for k<n (bug #61119) Nicholas R. Jankowski <jankowskin@asme.org> parents: 30206 diff changeset	264 %! assert (size (x), [3, 2]);
54774a713d7c nchoosek.m: Improve struct input handling for k<n (bug #61119) Nicholas R. Jankowski <jankowskin@asme.org> parents: 30206 diff changeset	265 %! assert (isstruct (x));
54774a713d7c nchoosek.m: Improve struct input handling for k<n (bug #61119) Nicholas R. Jankowski <jankowskin@asme.org> parents: 30206 diff changeset	266 %! assert (fieldnames (x), {"a"; "b"});
54774a713d7c nchoosek.m: Improve struct input handling for k<n (bug #61119) Nicholas R. Jankowski <jankowskin@asme.org> parents: 30206 diff changeset	267 %! x = nchoosek (s, 4);
54774a713d7c nchoosek.m: Improve struct input handling for k<n (bug #61119) Nicholas R. Jankowski <jankowskin@asme.org> parents: 30206 diff changeset	268 %! assert (size (x), [0, 4]);
30206 aaee7b170cb1 nchoosek.m: Allow struct inputs (bug #61119) Rik <rik@octave.org> parents: 30205 diff changeset	269 %! assert (isstruct (x));
aaee7b170cb1 nchoosek.m: Allow struct inputs (bug #61119) Rik <rik@octave.org> parents: 30205 diff changeset	270 %! assert (fieldnames (x), {"a"; "b"});
14090 281ecc6fb431 nchoosek.m: Update documentation, fix input validation, add more %!tests Rik <octave@nomad.inbox5.com> parents: 14062 diff changeset	271
19833 9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions. Rik <rik@octave.org> parents: 19697 diff changeset	272 ## Test input validation
28886 d8318c12d903 test: remove unnecessary BIST tests in m-files checking for excessive number of inputs. Rik <rik@octave.org> parents: 27985 diff changeset	273 %!error <Invalid call> nchoosek ()
d8318c12d903 test: remove unnecessary BIST tests in m-files checking for excessive number of inputs. Rik <rik@octave.org> parents: 27985 diff changeset	274 %!error <Invalid call> nchoosek (1)
30205 23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	275 %!error <first argument must be a scalar or a vector> nchoosek (ones (3, 3), 1)
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	276 %!error <K must be an integer .= 0> nchoosek (100, 2i)
23a907b2dbd5 nchoosek.m: Allow "char" and other non-numeric inputs (bug #61119) Rik <rik@octave.org> parents: 30204 diff changeset	277 %!error <K must be an integer .= 0> nchoosek (100, [2 3])
19059 83b88e20e9c1 nchoosek.m: Overhaul function. Rik <rik@octave.org> parents: 18795 diff changeset	278 %!error <K must be an integer .= 0> nchoosek (100, -45)
83b88e20e9c1 nchoosek.m: Overhaul function. Rik <rik@octave.org> parents: 18795 diff changeset	279 %!error <K must be an integer .= 0> nchoosek (100, 45.5)
83b88e20e9c1 nchoosek.m: Overhaul function. Rik <rik@octave.org> parents: 18795 diff changeset	280 %!error <N must be a non-negative integer .= K> nchoosek (100i, 2)
83b88e20e9c1 nchoosek.m: Overhaul function. Rik <rik@octave.org> parents: 18795 diff changeset	281 %!error <N must be a non-negative integer .= K> nchoosek (100, 145)
83b88e20e9c1 nchoosek.m: Overhaul function. Rik <rik@octave.org> parents: 18795 diff changeset	282 %!error <N must be a non-negative integer .= K> nchoosek (-100, 45)
83b88e20e9c1 nchoosek.m: Overhaul function. Rik <rik@octave.org> parents: 18795 diff changeset	283 %!error <N must be a non-negative integer .= K> nchoosek (100.5, 45)
83b88e20e9c1 nchoosek.m: Overhaul function. Rik <rik@octave.org> parents: 18795 diff changeset	284 %!warning <possible loss of precision> nchoosek (100, 45);

Mercurial > octave

annotate scripts/specfun/nchoosek.m @ 30218:750de16fd35c