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    Data connectivity & integrationPipeline Builder ExpressionsInterpolate geo point along linestring
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    Interpolate geo point along linestring

    Supported in: Batch, Streaming

    Returns a point interpolated along a line. Implementation interprets lines as the shortest path, using a spherical approximation of the globe.

    Expression categories: Geospatial

    Declared arguments

    • Fraction - Fraction of the total length of the linestring at which to pull a geo point, starting from the beginning of the linestring. Must be a float between 0 and 1.
      Expression<Decimal | Double | Float>
    • Linestring - Linestring along which to interpolate a geo point.
      Expression<Geometry>

    Output type: GeoPoint

    Examples

    Example 1: Base case

    Argument values:

    • Fraction: fraction
    • Linestring: linestring
    linestringfractionOutput
    {"type":"LineString","coordinates":[[0.0,2.0],[30.0,0.0]]}0.5{
     latitude: 1.0352686301676643,
     longitude: 15.004677545504547,
    }
    {"type":"LineString","coordinates":[[30.0,2.0],[50.0,3.0]]}0.8{
     latitude: 2.8256098405656185,
     longitude: 45.99752305664789,
    }
    {"type":"LineString","coordinates":[[45.0,9.0],[90.0,4.0]]}0.2{
     latitude: 8.363732883448177,
     longitude: 54.073497456494955,
    }

    Example 2: Base case

    Argument values:

    • Fraction: fraction
    • Linestring: linestring
    linestringfractionOutput
    {"type":"LineString","coordinates":[[0.0,2.0],[30.0,0.0]]}0.5{
     latitude: 1.0352686301676643,
     longitude: 15.004677545504547,
    }
    {"type":"LineString","coordinates":[[30.0,2.0],[50.0,3.0]]}0.8{
     latitude: 2.8256098405656185,
     longitude: 45.99752305664789,
    }
    {"type":"LineString","coordinates":[[45.0,9.0],[90.0,4.0]]}0.2{
     latitude: 8.363732883448177,
     longitude: 54.073497456494955,
    }

    Example 3: Base case

    Argument values:

    • Fraction: fraction
    • Linestring: linestring
    linestringfractionOutput
    {"type":"LineString","coordinates":[[0.0,2.0],[30.0,0.0]]}0.5{
     latitude: 1.0352686301676643,
     longitude: 15.004677545504547,
    }
    {"type":"LineString","coordinates":[[30.0,2.0],[50.0,3.0]]}0.8{
     latitude: 2.825609851378893,
     longitude: 45.99752329517703,
    }
    {"type":"LineString","coordinates":[[45.0,9.0],[90.0,4.0]]}0.2{
     latitude: 8.363732872387065,
     longitude: 54.0734975914614,
    }

    Example 4: Null case

    Argument values:

    • Fraction: fraction
    • Linestring: linestring
    linestringfractionOutput
    {"type":"LineString","coordinates":[[10.0,4.0],[75.0,0.0]]}nullnull
    {"type":"LineString","coordinates":[[10.0,8.0],[35.0,0.0]]}-0.5null
    {"type":"LineString","coordinates":[[10.0,8.0],[35.0,0.0]]}1.6null
    {"type":"MultiLineString","coordinates":[[[100.0,0.0]], [[102.0,2.0]]]}0.4null
    {"type":"GeometryCollection","geometries":{"type":"LineString","coordinates":[[10.0,4.0]]}}0.5null
    null1.0null

    Example 5: Edge case

    Description: Fraction values of 0 return a GeoPoint at the start point and fraction values of 1 return a GeoPoint at the end point. There exist floating point errors but should be precise enough for almost all use cases. Argument values:

    • Fraction: fraction
    • Linestring: linestring
    linestringfractionOutput
    {"type":"LineString","coordinates":[[10.0,4.0],[75.0,0.0]]}0.0{
     latitude: 4.0,
     longitude: 9.999999999999998,
    }
    {"type":"LineString","coordinates":[[10.0,8.0],[35.0,0.0]]}1.0{
     latitude: 0.0,
     longitude: 35.0,
    }
    {"type":"LineString","coordinates":[[10.0,8.4],[35.0,0.0],[163.0,67.9]]}1.0{
     latitude: 67.90000000000002,
     longitude: 163.0,
    }
    {"type":"LineString","coordinates":[[10.0,8.4],[35.0,0.0],[163.0,67.9]]}0.0{
     latitude: 8.400000000000002,
     longitude: 9.999999999999998,
    }