LengthIndexedLine (JTS Topology Suite 1.15.0 API)

java.lang.Object
- org.locationtech.jts.linearref.LengthIndexedLine

```
public class LengthIndexedLine
extends Object
```
Supports linear referencing along a linear Geometry using the length along the line as the index. Negative length values are taken as measured in the reverse direction from the end of the geometry. Out-of-range index values are handled by clamping them to the valid range of values. Non-simple lines (i.e. which loop back to cross or touch themselves) are supported.

Constructor Summary

Constructors
Constructor and Description

LengthIndexedLine(Geometry linearGeom)
Constructs an object which allows a linear Geometry to be linearly referenced using length as an index.

Constructors
Constructor and Description
`LengthIndexedLine(Geometry linearGeom)` Constructs an object which allows a linear `Geometry` to be linearly referenced using length as an index.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`double`	`clampIndex(double index)` Computes a valid index for this line by clamping the given index to the valid range of index values
`Geometry`	`extractLine(double startIndex, double endIndex)` Computes the `LineString` for the interval on the line between the given indices.
`Coordinate`	`extractPoint(double index)` Computes the `Coordinate` for the point on the line at the given index.
`Coordinate`	`extractPoint(double index, double offsetDistance)` Computes the `Coordinate` for the point on the line at the given index, offset by the given distance.
`double`	`getEndIndex()` Returns the index of the end of the line
`double`	`getStartIndex()` Returns the index of the start of the line
`double`	`indexOf(Coordinate pt)` Computes the minimum index for a point on the line.
`double`	`indexOfAfter(Coordinate pt, double minIndex)` Finds the index for a point on the line which is greater than the given index.
`double[]`	`indicesOf(Geometry subLine)` Computes the indices for a subline of the line.
`boolean`	`isValidIndex(double index)` Tests whether an index is in the valid index range for the line.
`double`	`project(Coordinate pt)` Computes the index for the closest point on the line to the given point.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - LengthIndexedLine
```
public LengthIndexedLine(Geometry linearGeom)
```
    Constructs an object which allows a linear Geometry to be linearly referenced using length as an index.
    
    Parameters:
    
    linearGeom - the linear geometry to reference along
- Method Detail
  - extractPoint
```
public Coordinate extractPoint(double index)
```
    Computes the Coordinate for the point on the line at the given index. If the index is out of range the first or last point on the line will be returned. The Z-ordinate of the computed point will be interpolated from the Z-ordinates of the line segment containing it, if they exist.
    
    Parameters:
    
    index - the index of the desired point
    
    Returns:
    
    the Coordinate at the given index
  - extractPoint
```
public Coordinate extractPoint(double index,
                               double offsetDistance)
```
    Computes the Coordinate for the point on the line at the given index, offset by the given distance. If the index is out of range the first or last point on the line will be returned. The computed point is offset to the left of the line if the offset distance is positive, to the right if negative. The Z-ordinate of the computed point will be interpolated from the Z-ordinates of the line segment containing it, if they exist.
    
    Parameters:
    
    index - the index of the desired point
    
    offsetDistance - the distance the point is offset from the segment (positive is to the left, negative is to the right)
    
    Returns:
    
    the Coordinate at the given index
  - extractLine
```
public Geometry extractLine(double startIndex,
                            double endIndex)
```
    Computes the LineString for the interval on the line between the given indices. If the endIndex lies before the startIndex, the computed geometry is reversed.
    
    Parameters:
    
    startIndex - the index of the start of the interval
    
    endIndex - the index of the end of the interval
    
    Returns:
    
    the linear interval between the indices
  - indexOf
```
public double indexOf(Coordinate pt)
```
    Computes the minimum index for a point on the line. If the line is not simple (i.e. loops back on itself) a single point may have more than one possible index. In this case, the smallest index is returned. The supplied point does not necessarily have to lie precisely on the line, but if it is far from the line the accuracy and performance of this function is not guaranteed. Use project(org.locationtech.jts.geom.Coordinate) to compute a guaranteed result for points which may be far from the line.
    
    Parameters:
    
    pt - a point on the line
    
    Returns:
    
    the minimum index of the point
    
    See Also:
    
    project(Coordinate)
  - indexOfAfter
```
public double indexOfAfter(Coordinate pt,
                           double minIndex)
```
    Finds the index for a point on the line which is greater than the given index. If no such index exists, returns minIndex. This method can be used to determine all indexes for a point which occurs more than once on a non-simple line. It can also be used to disambiguate cases where the given point lies slightly off the line and is equidistant from two different points on the line. The supplied point does not necessarily have to lie precisely on the line, but if it is far from the line the accuracy and performance of this function is not guaranteed. Use project(org.locationtech.jts.geom.Coordinate) to compute a guaranteed result for points which may be far from the line.
    
    Parameters:
    
    pt - a point on the line
    
    minIndex - the value the returned index must be greater than
    
    Returns:
    
    the index of the point greater than the given minimum index
    
    See Also:
    
    project(Coordinate)
  - indicesOf
```
public double[] indicesOf(Geometry subLine)
```
    Computes the indices for a subline of the line. (The subline must conform to the line; that is, all vertices in the subline (except possibly the first and last) must be vertices of the line and occur in the same order).
    
    Parameters:
    
    subLine - a subLine of the line
    
    Returns:
    
    a pair of indices for the start and end of the subline.
  - project
```
public double project(Coordinate pt)
```
    Computes the index for the closest point on the line to the given point. If more than one point has the closest distance the first one along the line is returned. (The point does not necessarily have to lie precisely on the line.)
    
    Parameters:
    
    pt - a point on the line
    
    Returns:
    
    the index of the point
  - getStartIndex
```
public double getStartIndex()
```
    Returns the index of the start of the line
    
    Returns:
    
    the start index
  - getEndIndex
```
public double getEndIndex()
```
    Returns the index of the end of the line
    
    Returns:
    
    the end index
  - isValidIndex
```
public boolean isValidIndex(double index)
```
    Tests whether an index is in the valid index range for the line.
    
    Parameters:
    
    index - the index to test
    
    Returns:
    
    true if the index is in the valid range
  - clampIndex
```
public double clampIndex(double index)
```
    Computes a valid index for this line by clamping the given index to the valid range of index values
    
    Returns:
    
    a valid index value

Class LengthIndexedLine

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

LengthIndexedLine

Method Detail

extractPoint

extractPoint

extractLine

indexOf

indexOfAfter

indicesOf

project

getStartIndex

getEndIndex

isValidIndex

clampIndex