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Create local repository for matrix toolboxes. Step #0 done.
author Antonio Pino Robles <data.script93@gmail.com>
date Wed, 06 May 2015 14:56:53 +0200
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8f23314345f4 Create local repository for matrix toolboxes. Step #0 done.
Antonio Pino Robles <data.script93@gmail.com>
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1 function A = sparsify(A, p)
8f23314345f4 Create local repository for matrix toolboxes. Step #0 done.
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2 %SPARSIFY Randomly set matrix elements to zero.
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3 % S = SPARSIFY(A, P) is A with elements randomly set to zero
8f23314345f4 Create local repository for matrix toolboxes. Step #0 done.
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4 % (S = S' if A is square and A = A', i.e. symmetry is preserved).
8f23314345f4 Create local repository for matrix toolboxes. Step #0 done.
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5 % Each element has probability P of being zeroed.
8f23314345f4 Create local repository for matrix toolboxes. Step #0 done.
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6 % Thus on average 100*P percent of the elements of A will be zeroed.
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7 % Default: P = 0.25.
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8f23314345f4 Create local repository for matrix toolboxes. Step #0 done.
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9 if nargin < 2, p = 0.25; end
8f23314345f4 Create local repository for matrix toolboxes. Step #0 done.
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10 if p<0 | p>1, error('Second parameter must be between 0 and 1 inclusive.'), end
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12 [m,n] = size(A);
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14 if ~isequal(A,A')
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15 A = A .* (rand(m,n) > p); % Unsymmetric case
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16 else
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17 A = triu(A,1) .* (rand(m,n) > p); % Preserve symmetry
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18 A = A + A';
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19 A = A + diag( diag(A) .* (rand(size(n,1)) > p) );
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20 end