I want to initialize a very large character array with the same character string
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The array is so large it takes forever for MATLAB to do it with a simple loop, e.g.;
for i = 1:N A(i) = 'String' end
I know this can be done numerically using ones (* the desired value) in a single line of code. Can it be done with a character string in a way that speeds up the process?
Thanks, David
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Answers (2)
Iain
on 4 Jun 2013
char_array = char(ones(N,1) * 'String');
cell_version = repmat({'String'},N,1);
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Ahmed
on 4 Jun 2013
Have you tried 'repmat'?
N = 100000;
A = repmat('String',N,1);
If you must use a for-loop, you should pre-allocate the array. If uninitialized, the growing of the array will consume a lot of time. Here, an example of preallocation and filling with loop.
N = 100000;
A = repmat(char(0),N,6);
for i = 1:N, A(i,:) = 'String'; end
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Jan
on 4 Jun 2013
It is much faster to operate on the columns and assign scalars:
N = 100000;
A = repmat(char(0),N,6);
S = 'String';
for k = 1:6
A(:, k) = S(k);
end
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