You can navigate through a matrix in one of two ways using the mouse or the keyboard.
The mouse provides easy navigation and selection of cells.
You can also navigate the matrix using the arrow keys. Presss the space bar to perform an edit. In instances where there are two clicks involved the space bar performs the select and edit in one.
In multi-dimensional matrices (MDMs), use Ctrl+Tab and Ctrl+Shift+Tab switch between tabs. When the correct tab is displayed, use the arrow keys to navigate in the matrix grid.
Where the matrix is X-in Cell
First click places an X (intersection) if the cell is empty.
Places an X (intersection) if the cell is displaying an inferred intersection.
Remove an X (remove intersection) if the cell contains an X.
Where the matrix is Text-in Cell
First click selects the cell.
Second click activates the text edit in the cell.
Pressing Esc cancels the edit.
Selecting a different cell, or moving focus away from the matrix confirms the edit.