Concatenating data from a variable within a MAT file in a loop

Within a loop, I want to 1) load a variable from a MAT file, 2) concatenate the newly loaded two-column data of varying lengths to a new variable array, and 3) save the variable to a new MAT file. I am fairly new to Matlab, but while I know how to add values to a given vector/array within a loop, this question has vexed me. Any suggestions?

EXAMPLE:

a=[load('fileA.mat','delta_length')];
b=[load('fileB.mat','delta_length')];
c=[load('fileB.mat','delta_length')];

new = [a.delta_length; b.delta_length; c.delta_length];

save('fileABC.mat','new');

In the above example, this is how I am doing it line by line, but the number of files I want to load could range from 1 to 10 or higher.

With my limited understanding I am trying something like this:

 new=[];
 for i=1:3
   a_i=[load('fileA.mat','delta_length')];
     new = [a_i.delta_length; ??how to keep appending a vector here??];
 end

 save('fileABC.mat','new');

Hopefully it's clear from this what I am trying to do. Any help much appreciated!

-Jason

Answer 1

[Azzi Abdelmalek]

new = [new;a_i.delta_length]

% Use also sprintf to generate fileA,fileB,...

new=[];
s='A':'C'
for i=1:3
  a_i=[load(sprintf('file%s.mat',s(i)),'delta_length')];
  new = [new;a_i.delta_length];
end

[Peds IT]

thanks for the answer - although i think my question wasn't quite clear, your answer still helped me figure out that at least the part i was struggling with was actually ok! plus, i learned something new.

for closure - here is my final code:

 [files,pathname] = uigetfile('*.mat', 'Select MAT files (use CTRL/COMM or  SHIFT)', ...
    'MultiSelect', 'on');

 source_file = char(files(1,1));
 animal_ID = source_file(1:11); %just grabbing needed identifying text

        delta_length=[];

        for i=1:numel(files)
            a=[load(files{1,i},'delta_length')];
            delta_length = [delta_length; a.delta_length];
        end

and 'delta_length' are just data from variables loaded from each file in the list that look something like this: e.g.: delta_length = [0 0 0;1 5 7]'; delta_length = [0 0 0 0 0; -2 3 0 10 100]'; etc....

thanks again...

[Azzi Abdelmalek]

Is it a question or just a comment?

[Peds IT]

just a comment with my solution. thanks.