docs/api/sql/Linear-Referencing/ST_InterpolatePoint.md

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# ST_InterpolatePoint

Introduction: Returns the interpolated measure value of a linear measured LineString at the point closest to the specified point.

!!!Note
    Make sure that both geometries have the same SRID, otherwise the function will throw an IllegalArgumentException.

Format: `ST_InterpolatePoint(linestringM: Geometry, point: Geometry)`

Return type: `Double`

Since: `v1.7.0`

SQL Example

```sql
SELECT ST_InterpolatePoint(
    ST_GeomFromWKT("LINESTRING M (0 0 0, 2 0 2, 4 0 4)"),
    ST_GeomFromWKT("POINT (1 1)")
    )
```

Output:

```
1.0
```