module:extras/evaluators.Trochoid
new module:extras/evaluators.Trochoid(radius, distFromCenter)
Augments: Curve
A curve evaluator object for a curve drawn by a circle that rolls along the X axis.
The following curves can be generated with this class (in the following
descriptions, R = radius
and D = distFromCenter).
- Cycloid: D = R (trochoid touching the X axis).
- Curtate cycloid: D < R (trochoid not touching the X axis).
- Prolate cycloid: D > R (trochoid crossing the X axis).
Parameters
radius(Type: number)
Radius of the rolling circle.distFromCenter(Type: number)
Distance from the center of the rolling circle to the drawing pen.
Methods
- endPoints
Gets the endpoints of this curve. - evaluate
Generates a point on the curve from the given U coordinate. - velocity
Finds the velocity (derivative) of this curve at the given point.
module:extras/evaluators~Trochoid#endPoints()
Gets the endpoints of this curve. For this curve evaluator object, the curve starts at 0 and ends at π*2.
Return Value
An array containing the two endpoints of the curve. The first number is the start of the curve, and the second number is the end of the curve. (Type: Array.<number>)
module:extras/evaluators~Trochoid#evaluate(u)
Generates a point on the curve from the given U coordinate.
Parameters
u(Type: number)
U coordinate.
Return Value
A 3-element array specifying a 3D point. Only the X and Y coordinates will be other than 0. (Type: Array.<number>)
module:extras/evaluators~Trochoid#velocity(u)
Finds the velocity (derivative) of this curve at the given point.
Parameters
u(Type: number)
Point on the curve to evaluate.
Return Value
An array giving the velocity vector. (Type: Array.<number>)