Importing matrices in text files and creating a structure with 100 entries

Hello there,

I was hoping that somebody could perhaps help me out with a problem that I have. I'm only learning how to use matlab.

I have 100 4x4 matrices in .txt files in a folder.

How could I import them and create a structure with 100 entries and in each entry there would be one matrix.

The reason I ask is because I'm trying to get the average of these matrices and this post provides a solution if the matrices are in this format.

http://www.mathworks.com/matlabcentral/newsreader/view_thread/292234

Thank you for your help

Regards

John

Answer 1

[Sean de Wolski]

FAQ:How to process a sequence of files

Also note, that if they're all the same size, you could stack them along the third dimension and then take the mean of the first and second dimension which would leave you with each matrice's mean.

[John]

Hi Sean thank you for replying,

I think I have the process to load the files down below? To be honest I just don't know who to create the structure and entries.

I would really appreciate some help or advice on the next step?

Regards

John

files = dir(fullfile(pwd,'*.txt'));

for k = 1 : numel(files)

%%%% reading the txt file

fid01 = fopen(fullfile(pwd,files(k).name));

idx = 0; tmparray = [];

tline = fgetl(fid01);

while ischar(tline)

idx = idx + 1;

tmparray(idx,:) = str2num(tline);

tline = fgetl(fid01);

end

fclose(fid01);

%%%% Create the structure and entries

end

[Sean de Wolski]

too much effort, use importdata() and a cell array (you can convert to struct later):

C = cell(100,1);

for ii = 1:100

C{ii} = importdata(filename(ii))

end

[John]

Hi again,

Please bear with me. So if the text files are called matrix1.txt, matrix2.txt etc

C = cell(100,1);

for ii = 1:100

C{ii} = importdata(matrix(ii))

end

Apologies if this is a very basic question!

[Sean de Wolski]

importdata(['matrix' num2str(ii) '.txt'])

[John]

Thank you Sean

[Sean de Wolski]

You're welcome!

Were you able to get it working?

[John]

Hi again,

Honestly I haven't been able to get it to work

This is the code I'm using

C = cell(100,1);

for ii = 1:100

C{ii} = importdata(['matrix' num2str(ii) '.txt']) ;

end

but I'm getting this error

??? Error using ==> importdata at 123

Unable to open file.

The files are just text files each containing a 4x4 matrix

Could you offer any further suggestions?

Thank you