The plt and pld functions return a point on a given line. You can specify the location of the point on the line either by its distance from the first point or parametrically by a t parameter.

pld(p1,p2,dist)

Calculates a point on the line passing through points p1 and p2. The parameter dist defines the distance of the point from the point p1.

plt(p1,p2,t)

Calculates a point on the line passing through points p1 and p2. The parameter t defines the parametric location of the point on the line.

The following are examples of the parameter t:

If t=0 the point is p1

If t=0.5 the point is the midpoint between p1 and p2

If t=1 the point is p2