Curve Measurement Functions Reference (AutoLISP/ActiveX)

Note: ActiveX support in AutoLISP is limited to Windows only; not available on Mac OS or Web.

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

Curve measurement functions		Platforms
		Windows		Mac OS		Web
Function	Description	AutoCAD	AutoCAD LT	AutoCAD	AutoCAD LT	AutoCAD
(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	✓	✓	--	--	--