Curve Measurement Functions Reference (AutoLISP/ActiveX)

Note: ActiveX support in AutoLISP is limited to Windows only.

The following table provides summary descriptions of the AutoLISP curve measurement functions.

Curve measurement functions
Function	Description
(vlax-curve-getArea curve-obj)	Returns the area inside the curve
(vlax-curve-getClosestPointTo curve-obj givenPnt [extend])	Returns the point (in WCS coordinates) on a curve that is nearest to the specified point
(vlax-curve-getClosestPointToProjection curve-obj givenPnt normal [extend])	Returns the closest point (in WCS) on a curve after projecting the curve onto a plane
(vlax-curve-getDistAtParam curve-obj param)	Returns the length of the curve's segment from the curve's beginning to the specified parameter
(vlax-curve-getDistAtPoint curve-obj point)	Returns the length of the curve's segment between the curve's start point and the specified point
(vlax-curve-getEndParam curve-obj)	Returns the parameter of the endpoint of the curve
(vlax-curve-getEndPoint curve-obj)	Returns the endpoint (in WCS coordinates) of the curve
(vlax-curve-getFirstDeriv curve-obj param)	Returns the first derivative (in WCS coordinates) of a curve at the specified location
(vlax-curve-getParamAtDist curve-obj point)	Returns the parameter of a curve at the specified distance from the beginning of the curve
(vlax-curve-getParamAtPoint curve-obj dist)	Returns the parameter of the curve at the point
(vlax-curve-getPointAtDist curve-obj dist)	Returns the point (in WCS coordinates) along a curve at the distance specified by the user
(vlax-curve-getPointAtParam curve-obj param)	Determines the point on the curve that corresponds to the param parameter and returns the point
(vlax-curve-getSecondDeriv curve-obj param)	Returns the second derivative (in WCS coordinates) of a curve at the specified location
(vlax-curve-getStartParam curve-obj)	Returns the start parameter on the curve
(vlax-curve-getStartPoint curve-obj)	Returns the start point (in WCS coordinates) of the curve
(vlax-curve-isClosed curve-obj)	Determines if the specified curve is closed (i.e., start point is same as endpoint)
(vlax-curve-isPeriodic curve-obj)	Determines if the specified curve has an infinite range in both directions and there is a period value dT, such that there is a point on curve at ( u + dT) = point on curve ( u), for any parameter u
(vlax-curve-isPlanar curve-obj)	Determines if there is a plane that contains the curve