GetDistancesAtM Method (IGeometryEngine)

In This Topic

Gets a list of distances along the multipart at points with the specified M-value.

Syntax

C#
Visual Basic (Declaration)

IReadOnlyList<double> GetDistancesAtM( 
   Multipart multipart,
   AsRatioOrLength asRatioOrLength,
   double mValue
)

Function GetDistancesAtM( _
   ByVal multipart As Multipart, _
   ByVal asRatioOrLength As AsRatioOrLength, _
   ByVal mValue As Double _
) As IReadOnlyList(Of Double)

Parameters

multipart: The multipart from which to get the distances.
asRatioOrLength: Indicates whether the distances should be returned as lengths or ratios along the multipart.
mValue: The M-value from which to get the distances.

Return Value

A list of distances. If the input M-value is NaN or cannot be found, then an empty list is returned.

Exceptions

Exception	Description
System.ArgumentNullException	The input multipart is null.
System.InvalidOperationException	The input multipart is not M-Aware.

Example

Get a list of distances along the multipart at points with the specified M-value - GetDistancesAtM

string json = "{\"hasM\":true,\"paths\":[[[-4,1,1],[-4,3,2],[-2,3,3],[-2,5,1]],[[3,5,1],[3,2,2],[6,2,3],[6,-2,2]]]}";
Polyline polyline = PolylineBuilderEx.FromJson(json);

// Get the distances as length measured from the start of the multipart
IReadOnlyList<double> distances = GeometryEngine.Instance.GetDistancesAtM(polyline, AsRatioOrLength.AsLength, 2);
// distances.Count = 4
// distances[0] = 2 measured to the point (-4, 3, 2)
// distances[1] = 5 measured to the point (-2, 4, 2). Its M-value is interpolated from the segment (-2, 3, 3) -> (-2, 5, 1)
// distances[2] = 9 measured to the point (3, 2, 2) 
// distances[3] = 16 measured to the point (6, -2, 2)

// Get the distances as a ratio of the distance measured from the start of the multipart and the total length of the multipart
distances = GeometryEngine.Instance.GetDistancesAtM(polyline, AsRatioOrLength.AsRatio, 2);
// distances.Count = 4;
// distances are { 0.125, 0.3125, 0.5625, 1 }

Requirements

Target Platforms: Windows 11, Windows 10

ArcGIS Pro version: 3.3 or higher.

Reference

IGeometryEngine Interface
IGeometryEngine Members

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