Methods for editing the grid include deleting grid lines, moving grid lines, adding grid lines, subdividing elements, changing the grid angle, and “smoothing” the grid.
To delete a grid line, the user selects Grid|Delete Grid Line or clicks the Delete grid line button 
. Then the user moves the cursor over the grid line to be deleted. When the cursor is over a grid line, it will change from an arrow to an X. If the mouse button is clicked at that point, the grid line will be deleted.
To move grid lines, the user first selects Grid|Move Grid Line or clicks on the Move grid line button 
. The user next moves the cursor over one of the views of the model. When the cursor is over a grid line, the cursor will change shape so that it resembles the picture on the Move grid line button . Then the user clicks down the mouse button, moves the cursor, and releases the mouse button. The grid line that was under the cursor when the mouse button was pressed will be moved to the location where the mouse button was released.
To add a grid line, the user selects either Grid|Add Vertical Grid Line or Grid|Add Horizontal Grid Line or clicks on the Add vertical grid line 
or Add horizontal grid line 
buttons. Then the user moves the cursor over one of the views of the model. The cursor will change to a line parallel to one of the edges of the grid. When the user clicks the mouse, a new grid line will be added at the position where the mouse was clicked.
The grid angle can be changed in two ways. First, the user can choose Grid|Specify Grid Angle... The Grid Angle dialog box will appear in which the user can specify the grid angle. Another way is to choose Grid|Drag to Rotate or click on the Drag to rotate grid button 
. Then the user clicks down on the top view of the model and moves the cursor before releasing the mouse button.
Additional methods of editing the grid are described in Subdivide Columns, Rows, and Layers dialog box, Set Widths of Columns, Rows, and Layers dialog box, Grid Angle dialog box, Generate Grid dialog box, Smooth Grid dialog box, and Grid Spacing dialog box.
Most of these methods can not be used with Footprint grids because the cell spacing is required to be uniform.
