Guidance on using For Loops for loading data and applying function.

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I have 11 directories (-2d to 8d) each containing 7 data files (100mm.dat to 700mm.dat). At present in order to load these files in a single script I am doing the following:
load ./-2d/100mm.dat
load ./-2d/200mm.dat
load ./-2d/300mm.dat
load ./-2d/400mm.dat
load ./-2d/500mm.dat
load ./-2d/600mm.dat
load ./-2d/700mm.dat
m2d1 = X100mm;
m2d2 = X200mm;
m2d3 = X300mm;
m2d4 = X400mm;
m2d5 = X500mm;
m2d6 = X600mm;
m2d7 = X700mm;
for each directory. Now this works fine, it gets the data loaded up for me to play around with but my instinct tells me that there is a better way to write this and I was thinking that it may involve a for loop, something like:
for i=1:7;
load ./-2d/(i)00mm.dat;
m2d(i) = X(i)00mm;
end
I know the above is probably nonsense to MATLAB but I am just trying to express the idea I have in my mind. Likewise for the directories would it be possible to use a for loop for that as well, something like:
for j=1:8;
for i=1:7;
load ./(j)d/(i)00mm.dat;
m2d(i) = X(i)00mm;
end
end
Thanks in advance, I hope the above makes sense.
  1 Comment
Daniel Potter
Daniel Potter on 5 Jun 2015
For anyone from the future looking at this the solution given by Ingrid below works a charm. For the two loops above I used:
for i=1:7;
stringDat = ['./-2d/' num2str(i) '00mm.dat'];
load(stringDat);
eval(['m2d' num2str(i) '= X' num2str(i) '00mm;']);
end
and
for j=1:8;
for i=1:7;
stringDat = ['./' num2str(j) 'd/' num2str(i) '00mm.dat'];
load(stringDat);
eval(['m' num2str(j) 'd' num2str(i) '= X' num2str(i) '00mm;']);
end
end

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Accepted Answer

Ingrid
Ingrid on 5 Jun 2015
for loading a dat file you can generate the string of the file as shown below and then use this string directly as input for the load function
to assign the changing variable names you will need to use eval
for i=1:7;
stringDat = ['./-2d/' num2str(i) '00mm.dat'];
load(stringDat);
eval(['m2d(i) = X' num2str(i) '00mm']);
end
  2 Comments
Daniel Potter
Daniel Potter on 5 Jun 2015
Thanks very much Ingrid, num2str was very much the droid I was looking for.

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More Answers (1)

Guillaume
Guillaume on 5 Jun 2015
Edited: Guillaume on 5 Jun 2015
md = cell(11, 7); %rows are the d, columns are the mm
d = -2:8;
m = 100:100:700;
for id = 1:numel(d)
for im = 1:numel(m)
md(id, im) = load(sprintf('./%dd/%dmm.dat', d(id), m(im)));
end
end
will load all your data into a single 2D cell array.
edit: made a stupid error with the indexing.
  2 Comments
Daniel Potter
Daniel Potter on 5 Jun 2015
Works grand, and I am able to recover the data to play around with using:
data = cell2mat(md(1,1));
Is there a way to get this inside the loop. The eval command would work again here;
eval(['s',num2str(id),'d',num2str(im),'=cell2mat(md(',num2str(id),',',num2str(im),'));']);
but from what I have been reading this is again not good practice.

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