How to | Update Parts of a Matrix
The Wolfram Language has many matrix operations that support operations such as building, computing, and visualizing matrices. It also has a rich language for picking out parts of matrices and assigning new values to them.
Use [[...]] (the short form of Part) on the left-hand side of an assignment to set an element:
To set an entire column, select all rows with All and specify the column:
To set a submatrix you can use the short form of Span (;;).
Update the highlighted submatrix by using the short form of Span (;;) to specify the relevant span of rows and columns: