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ISegment.QueryCurvature Method (ArcObjects .NET 10.8 SDK)
 ArcObjects Help for .NET developers > ArcObjects Help for .NET developers > ArcObjects namespaces > Geometry > ESRI.ArcGIS.Geometry > Interfaces > IS > ISegment Interface > ISegment.QueryCurvature Method
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ISegment.QueryCurvature Method

Finds curvature and unit vector starting at point on segment and directed to embedded circle center.

```[Visual Basic .NET]
Public Sub QueryCurvature ( _
ByVal DistanceAlongCurve As Double, _
ByVal asRatio As Boolean, _
ByRef curvature As Double, _
ByVal unitVector As ILine _
)
```
```[C#]
public void QueryCurvature (
double DistanceAlongCurve,
bool asRatio,
ref double curvature,
ref ILine unitVector
);
```
```[C++]
HRESULT QueryCurvature(
double DistanceAlongCurve,
VARIANT_BOOL asRatio,
System.Double* curvature,
ILine* unitVector
);
```
```[C++]
Parameters
DistanceAlongCurve
DistanceAlongCurve is a parameter of type double
asRatio
asRatio is a parameter of type bool
curvature [out]
curvature is a parameter of type double*
unitVector
unitVector is a parameter of type ILine*
```

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Description

Returns the curvature at a specified distance along the segment.  The distance can be given explicitly or as a ratio of the entire length of the segment.  The curvature is returned as a Line representing a directional unit vector (in the direction going from the From Point to the To Point) and a double representing the magnitude of the vector of curvature.

Remarks

The unit vector returned by QueryCurvature points toward the center of the circle that has the same first and second derivative at the queried point with a curvature value equal to 1 / Radius of that circle.

See Also

ISegment Interface