How can I use different elements that are in a matrix, while they are read in a 'for' loop?

Good morning,

I have to work with data that it's imported from an Excel document. This data takes form as a matrix [4x2], however I need to keep adding data to the Excel so it might be a matrix [4x3], [4x4] , etc. After introducing all the data, I have to work with each column individually, because each row means different things. For that reason, I would like to know if there is any kind of 'for' loop that reads all the colums individually that will form the matrix and let me , for example, use the first and second element of each column to calculate a sum.

Another thing that it might work is split the matrix by columns and work just with the rows but I read on another questions that its a bad idea --' Apologizes in advance for my poor Matlab programming skills and my English,

Thank you for your help,

Best regards

Answer 1

[KSSV]

A = rand(4,3) ;   % A random matrix
B1 = A(1,:)    % Extracts entire first row 
B2 = A(:,1)   % Extracts entire first column 
B3 = A(2,3)   % Extracts 2nd row, 3rd column element

Extracting the rows, columns and elements you want is very easy. Read about MATLAB matrix indexing. https://in.mathworks.com/company/newsletters/articles/matrix-indexing-in-matlab.html