Assistance with creating multidimensional matrices

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Aaron 2012-7-11

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https://ww2.mathworks.cn/matlabcentral/answers/43363-assistance-with-creating-multidimensional-matrices

I have created a program shown below:

Rows = input('Enter the number of rows in the matrix: '); Columns = input('Enter the number of columns in the matrix: '); for i = 1:Rows for j = 1:Columns fprintf('Enter A(%0.0f,%0.0f):',i,j); A(i,j) = input(' '); end end display(A)

I want to be able to run this program using different matrix dimensions, but when I run a 1x8 matrix, for example, and then try to run 8x1 matrix afterwards, I get an 8x8 matrix that has a bunch of zeros, which I don't want. I've noticed that the workspace saves the initial matrix and since. Am I able to correct this in my program or do I just have to clear the workspace every time I run this program?

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Answer 1

Ryan 2012-7-11

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编辑：Ryan 2012-7-11

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I would pre-allocate A before the for loop by using

 A = zeros(Rows,Cols); %Creates matrix of 0's
 % This will also act to clear your previous value of A by replacing it with the 
 % zero matrix of the input size
 % An alternative method would be to use 'clear A' before the code to empty the 
 % variable each run

If you are looking to save each run of A into a 3-dimensional array, then you'll need to save each matrix run in a cell array since each run results in a matrix of a different size.