How to concatenate several matrices into one matrix?

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Negar
Negar on 17 Jan 2015
Answered: Negar on 18 Jan 2015
Hello all,
I have 3696 matrices with different number of rows but similar number of columns. Is there a way to concatenate them? I know how to do this with two matrices by C = [A B], but what about these many?
Thank you, Negar

Accepted Answer

Shoaibur Rahman
Shoaibur Rahman on 17 Jan 2015
Perhaps, you mistyped. It is C = [A; B] for different number of rows, but similar number of columns. Anyway, how your matrices are named, like do they have a regular pattern? If I assume that they are named as A1, A2, A3..........A3696, then you can use the following technique:
A1 = rand(3,5); % matrix 1
A2 = rand(2,5); % matrix 2
.
.
. % all other matrices in between
.
.
A3696 = rand(1,5); % matrix 3696
B = [];
for k = 1:3696
m = strcat('A',num2str(k));
B = [B; eval(genvarname(m),'=m')];
end
  1 Comment
Shoaibur Rahman
Shoaibur Rahman on 17 Jan 2015
If you have to read matrices from a file, as Image Analyst says below that sounds more reasonable, then it will be easier, but vastly depend on how your data is organized. Very roughly speaking, replace m in this code by the header names (which are supposed to be names of the matrices).

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More Answers (2)

Image Analyst
Image Analyst on 17 Jan 2015
It seems doubtful that you'd have 3696 uniquely named variables in your program so I guess you must be planning on retrieving these matrices from files. In that case, use the code in the FAQ: http://matlab.wikia.com/wiki/FAQ#How_can_I_process_a_sequence_of_files.3F

Negar
Negar on 18 Jan 2015
Hello, sorry for answering so late, my problem is unfortunately more complex than what I had imagined. I'll try to post it again. Thank you for taking the time. Negar

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