Shapes
Creates a ridge-shaped curve consisting of four points. The shape originates from the two center points and will lie at a position of 100 by default. The corresponding track must be selected.
Creates a curve that ascends and descends linearly from 0 to 100 between the first and last key of a given track. The corresponding track must be selected.
Selecting this option will open a small dialog window in which you can enter simple or complex mathematical functions with which just about any imaginable F-Curve can be created. The Keys setting defines the number of in-betweens. The variable is t, which runs from 0 (sequence start) to 1 (sequence end). Angles for trigonometric functions must be given in radians. The corresponding track must be selected.
A llst with possible formulas can be found here.
If you enter sin(t*2*pi) for s(t) and 4 for Keys, the following curve will result: