How to extract a row from a matrix in Matlab and Octave

To extract a row from a matrix in Matlab and Octave, type the row number (n) and colon symbol (:) instead of the column number.

M(n,:)

This command extracts the nth row from the array.

Example

Define a matrix 2x3

X = [1 2 1 ; 3 1 1]

The matrix has this structure

1 2 1
3 1 1

To extract the first row type

X(1,:)

The command extracts the first row

1 2 1

To extract the second row type

X(2,:)

The command extracts the second row

3 1 1