Storing data in an array from a for loop

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Yro
Yro on 13 Mar 2020
Commented: Cris LaPierre on 13 Mar 2020
Hi, I want to store the array (generations) obtained in each cycle for (95 arrays). With the following code I only get the arrangement corresponding to the last loop. Any ideas how to store the obtained arrays (generations) in a single array. Thanks in advance.
num_generations = 94 ;
matrices = {};
for ii = 0:num_generations
file = sprintf('population_%d.dat', ii);
generations_fid = fopen(file, 'r');
while ~feof(generations_fid)
generations = cell2mat(textscan(generations_fid, repmat('%f', 1, (3)))); % array to store
if isempty(generations)
fgetl(generations_fid);
else
matrices{end+1} = generations;
end
end
fclose(generations_fid);
end
  3 Comments
Yro
Yro on 13 Mar 2020
Thanks for your reply. Yes, they have the same number of columns, 3. This is a sample.
Thanks.
generations =
-2.7770 -4.9399 -16.7734
-2.7770 -4.9107 -16.6909
-2.7770 -4.8687 -16.5732
-2.7770 -4.8534 -16.5307
-2.6882 -4.9399 -16.4805
-2.6806 -4.9399 -16.4221
-2.6882 -4.9107 -16.3989
-2.6806 -4.9107 -16.3408
-2.6882 -4.8687 -16.2825
-2.6882 -4.8534 -16.2404
Cris LaPierre
Cris LaPierre on 13 Mar 2020
This appears to be the data once it has been loaded into MATLAB. Could you share what the dat file looks like as well? To Mohammed's point below, I'm not sure you need all the code you have, but without knowing what your data looks like, it's hard to say.

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Answers (1)

Mohammad Sami
Mohammad Sami on 13 Mar 2020
Edited: Mohammad Sami on 13 Mar 2020
You don't need to read your file line by line. textscan can scan the entire file in one pass (unless the format spec keep changing in your file).
num_generations = 94 ;
matrices = {};
for ii = 0:num_generations
file = sprintf('population_%d.dat', ii);
generations_fid = fopen(file, 'r');
generations = cell2mat(textscan(generations_fid, repmat('%f', 1, 3))); % array to store
matrices{ii+1} = generations;
fclose(generations_fid);
end

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