MATLAB: Insert zero column in a m×n matrix

MATLAB

hello, i want to insert a zero column in the beginning of a matrix. say for example, if i have 5×5 matrix. if i want to insert zero column in the beginning then the matrix will be 5×6 matrix, so now the first column in this matrix will be zeros. how do i do it? need some help. Thank you.

Best Answer

For a given matrix A:

A = rand(5,5);

Using square braces to concatenate:

A_zeros = [zeros(size(A,1),1) A];

Using the cat() command:

A_zeros = cat(2, zeros(size(A,1),1), A);

Related Solutions

MATLAB: How to insert a column with zeros in the second column of a mxn matrix

Brute force:

 A = [1 2 3; 4 5 6; 7 8 9]
 A = [zeros(size(A,1),1) A];
 A(:,[1 2]) = A(:,[2 1])

MATLAB: Removing zero element rows in a m×n matrix

That is a common error. After you assign [] to remove a row, the matrix now has fewer rows, but you proceed as if it still has as many rows as it used to have. Eventually you will index a row that no longer exists.

Easiest fix: loop backwards, so that the rows you have not examined yet will not have been moved.

Better fix: use logical indexing and do everything at the same time:

new_a = a(any(a,2),:);

new_a = a;
new_a(~any(a,2),:) = [];

Best Answer

Related Solutions

MATLAB: How to insert a column with zeros in the second column of a mxn matrix

MATLAB: Removing zero element rows in a m×n matrix

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