Locus

Selection prerequisites: The object whose locus you want to construct (the driven object) and a point (the driver) that determines the position of that object. The driver must be constructed on a path; or you can select an independent point as the driver and a separate unrelated path object.

Constructs the locus of the selected object as the driver point moves along its path. Generally, a locus is the set of points (or other objects) that satisfies some mathematical condition. In Sketchpad, a locus is defined as the set of locations of an object—the driven object—whose position or shape is determined by the motion of a driver point as it moves along a path. You can construct loci of points, straight objects, circles, arcs, or interiors. The selected driver must be constructed as a Point On Object that controls the position of the driven object. Alternately, you may select as the driver an independent point that determines the position of the driven object, in which case you must also select an unrelated path along which the driver can travel.

Driver: Point on circle

Driven object: Point on segment

Result: Point locus

Driver: Independent point

Path: Arc

Driven object: Segment

Result: Segment locus

You can use Plot Properties to change the number of samples in a locus and to determine whether a point locus is displayed as discrete or continuous.