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comparison m-toolbox/classes/+utils/@math/randelement.m @ 0:f0afece42f48
Import.
| author | Daniele Nicolodi <nicolodi@science.unitn.it> |
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| date | Wed, 23 Nov 2011 19:22:13 +0100 |
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| -1:000000000000 | 0:f0afece42f48 |
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| 1 % RANDELEMENT(VECTOR,J) returns J random samples chosen in the VECTOR array. | |
| 2 % | |
| 3 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
| 4 % | |
| 5 % DESCRIPTION: RANDELEMENT(VECTOR,N) returns N random samples chosen in the | |
| 6 % VECTOR array. If VECTOR is a scalar, | |
| 7 % than it answers with N samples from | |
| 8 % 1:1:VECTOR. | |
| 9 % | |
| 10 % CALL: out = randelement(arr, j) | |
| 11 % | |
| 12 % INPUTS: arr - numerical vector array or cell vector array; can be | |
| 13 % single line or single column. | |
| 14 % j - number of samples to extract | |
| 15 % | |
| 16 % OUTPUTS: out - numerical vector array or cell vector array, shaped as | |
| 17 % the input 'arr', containing j elements chosen among | |
| 18 % those included in 'arr'. | |
| 19 % | |
| 20 % VERSION: $Id: randelement.m,v 1.5 2009/08/10 00:49:50 nicola Exp $ | |
| 21 % | |
| 22 % HISTORY: 06-02-2008 N Tateo | |
| 23 % Creation | |
| 24 % | |
| 25 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
| 26 | |
| 27 function out = randelement(arr, j) | |
| 28 | |
| 29 if nargin < 2 | |
| 30 error('randelement:tooFewInputs','The randelement function requires two input arguments.'); | |
| 31 elseif ~isa(arr,'double') && ~isa(arr,'cell') | |
| 32 error('randelement:wrongInput','The input to the randelement function must be a numerical or cell array.') | |
| 33 elseif ~isvector(arr) | |
| 34 error('randelement:wrongShape','The input to the randelement function must be a vector.') | |
| 35 end | |
| 36 | |
| 37 N = length(arr); | |
| 38 if N==1 | |
| 39 if iscell(arr), arr = num2cell([1:1:arr{1}]); | |
| 40 else arr = [1:1:arr]; | |
| 41 end | |
| 42 N = length(arr); | |
| 43 end | |
| 44 out = arr(randi(N,1,j)); | |
| 45 | |
| 46 if size(arr,1)==1 % reshape as a row vector | |
| 47 out = reshape(out,1,[]); | |
| 48 else % reshape as a column vector | |
| 49 out = reshape(out,[],1); | |
| 50 end | |
| 51 | |
| 52 end | |
| 53 % END | |
| 54 |