set the second column from the left to the column number from an unlimited range in matlab

To set the second column from the left to the column number from an unlimited range in MATLAB, you can use indexing and a for loop with conditional statements. Here's an example code snippet:

main.m
% create a matrix with an unlimited number of columns
M = rand(3,100);

% set the second column from the left to the column number
for i = 1:size(M,2)
    if i == 2
        M(:,i) = i;
    end
end
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In this code, we first create a 3 x 100 matrix using the rand() function, which generates random numbers between 0 and 1. Then, we use a for loop to iterate through each column of the matrix. Inside the loop, we use a conditional statement (if i == 2) to check if the current column is the second column from the left. If it is, we use indexing (M(:,i) = i) to set all rows of that column to the column number (i).

After running this code, the second column from the left of the M matrix will be equal to 2, and all other columns will still have their original values (random numbers between 0 and 1).