Modifying Mask Files

The grid mask created for the buffered grid may be modified with the mask and unmask commands.

Command	Option	Meaning
unmask		The unmask qualifier removes the current mask from the buffered grid allowing the grid to cover the entire area.
mask		A mask file may be applied to the grid with the `/area` qualifier. The default is applied if no qualifiers are specified.
	`/area=`	mask file area name.
	`/grid=`	grid file. The mask from another grid may be applied with the `/grid` qualifier.
	`/equation=`	logical expression. The `/equation` qualifier allows the specification of a logical expression describing an area in the mask. A logical expression is one that evaluates to zero (false) or non-zero (true).
	`/distance=`	distance from a data point. The `/distance` qualifier to mask out all points that are further than the specified distance from one of the loaded data points.
	`/layer=`	layer name (or layer, object...). The `/layer` and `/design_DB` qualifiers allow you to mask out points that fall outside of a particular polygon, or set of polygons.
	`/design_dB=`	design database.
	`/replace=`	the `/replace` qualifier to replace the current mask rather than update it.

Example:

mask/replace/equation="z lt 180"

The above expression will mask the buffered grid where the 'z' value of the grid cells is less than 180.