Assgin a name to sequentially imported files

Experts,

I have imported 8 files sequentially using this piece of code

for i=1:8
  fileName=['data' num2str(i)]; 
  dataStruct.(fileName)=load([fileName '.csv']);
end

Now I want to assign a variable to the first imported file, do some operations on it and then save the results. Then, assign the second imported file to the same variable and do the same operations. Then the third one and so on. How can I do that? I mention the WRONG way that I used to be clear below:

for k=1:8
M5=dataStruct.data(k);
[I,J]=size(M5);
BLAH...BLA... BLAH 
end

Which results in this error {{{Reference to non-existent field 'data'.}}} Can you please help me? I do appreciate your attention

[Stephen23]

The cause of the error is quite straightforward: you define each fieldname like this:

['data' num2str(i)]

giving filenames data1, data2, etc. And then you try to access the field data, which does not exist, thus the error. Note that indexing into that field data(k) is totally unrelated to the fieldname.

Answer 1

[Stephen23]

I don't see any reason why you need to use a structure: it just makes accessing the data more complex for you and serves no obvious purpose. A cell array would be much simpler:

N = 8;
C = cell(1,N);
for k = 1:N
    fileName = sprintf('data%d.csv',k); 
    C{k} = load(fileName,'-ascii');
end

And then accessing the data in the cell array is trivial with just indexing:

for k = 1:numel(C)
    M = C{k};
    ...
end

If you really want to use a structure then you could use a non-scalar structure:

N = 8;
S = struct('data',cell(1,N));
for k = 1:8
     fileName = sprintf('data%d.csv',k);
     S(k).data = load(fileName,'-ascii');
end

and then simply

for k = 1:numel(S)
     M = S(k).data;
     ...
end

Answer 2

[Image Analyst]

See the FAQ for much, MUCH better code samples: http://matlab.wikia.com/wiki/FAQ#How_can_I_process_a_sequence_of_files.3F

Answer 3

[per isakson]

Given dataStruct. An alternative approach

results = structfun( @do_some_operations_on, dataStruct, 'uni',false );

where

function    out = do_some_operations_on( data )
    BLAH ... BLA... BLAH 
end