MATLAB: How can i append a matrix n times

concatenationmatrixmatrix manipulation

i have a matrix "A" which has to be concatenated 600 times to make a new matrix. please help me doing it

for example, i have a matrix B = [1 2], i want to create a matrix "C" which is matrix B concatenated 5 times

C = [B B B B B];

which would evaluate to [1 2 1 2 1 2 1 2 1 2]

what should i do to make it 600 times!!!!

Best Answer

You are looking for the repmat function.

B = [1 2];
C = repmat(B,1,600)

This will repeat matrix B for 1 row and 600 columns.

Related Solutions

MATLAB: Columnwise ‘-append’

Could you simplify your input by creating the string first using MATLAB code and then use dlmwrite to add a single string? This might make it easier.

For clarity, here is what I'm thinking

for i=1:4
    fname = (sprintf('OutputFile_%d.txt',i));
    fin = Coordinates{i};
    time = Times{i};
    fileID = fopen(fname);
    for k = 1:n
        coordString = '';
        for j = 1:21
            coordString = [coordString ',' num2str(fin(k,j))];
        end
        timeString = '';
        for j = 1:24
            timeString = [timeString time(k,j)];
        end
        stringToAdd = [coordString timeString];
        end
        fprintf(fileID,'%s',stringToAdd);
    end
    fclose(fileID)
end

You can do some fancy indexing to avoid some of those for loops, but I left them there for clarity. The best part about this method is that it is easy to debug cause you can see each string you are about to write.

There may be a way to do it with dlmwrite, but I honestly don't know it (I welcome anyone to set me straight :) )

Hope this helps!

MATLAB: Call a matrix in a matrix

You can have cell like this:

B = rand(3);
C = rand(3);
A{1} = B;
A{2} = C;

Best Answer

Related Solutions

MATLAB: Columnwise ‘-append’

MATLAB: Call a matrix in a matrix

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