# ogrlineref

Create linear reference and provide some calculations using it

## Synopsis

    ogrlineref [--help] [--help-general] [-progress] [-quiet]
               [-f <format_name>] [-dsco <NAME>=<VALUE>]... [-lco <NAME>=<VALUE>]...
               [-create]
               [-l <src_line_datasource_name>] [-ln <layer_name>] [-lf <field_name>]
               [-p <src_repers_datasource_name>] [-pn <layer_name>] [-pm <pos_field_name>] [-pf <field_name>]
               [-r <src_parts_datasource_name>] [-rn <layer_name>]
               [-o <dst_datasource_name>] [-on <layer_name>] [-of <field_name>] [-s <step>]
               [-get_pos] [-x <long>] [-y <lat>]
               [-get_coord] [-m <position>]
               [-get_subline] [-mb <position>] [-me <position>]

## Description

The ogrlineref program can be used to:

- create a linear reference file from input data

- return the "linear referenced" distance for the projection of the input coordinates (point) on the path

- return the coordinates (point) on the path according to the "linear referenced" distance

- return the portion of the path according to the "linear referenced" begin and end distances

The ogrlineref utility creates a linear reference - a file containing segments of a certain length (e.g. 1 km in reference units.) The user can get coordinates, linear referenced distances or sublines (subpaths) from this file. The utility does not require the `M` or `Z` components in the geometry. The results can be stored in any OGR supported format. Also some information is written to the stdout.

--help

  Show this help message and exit

--help-general

  Gives a brief usage message for the generic GDAL commandline options and exit.

-progress

  Show progress.

-quiet

  Suppress all messages except errors and results.

-f <format_name>

  Select an output format name. The default is to create a shapefile.

-dsco <NAME>=<VALUE>

  Dataset creation option (format specific)

-lco <NAME>=<VALUE>

  Layer creation option (format specific).

-create

  Create the linear reference file (linestring of parts).

-l <src_line_datasource_name>

  The path to input linestring datasource (e.g. the road)

-ln <layer_name>

  The layer name in datasource

-lf <field_name>

  The field name of unique values to separate the input lines (e.g. the set of roads).

-p <src_repers_datasource_name>

  The path to linear references points (e.g. the road mile-stones)

-pn <layer_name>

  The layer name in datasource

-pm <pos_field_name>

  The field name of distances along path (e.g. mile-stones values)

-pf <field_name>

  The field name of unique values to map input reference points to lines.

-r <src_parts_datasource_name>

  The path to linear reference file.

-rn <layer_name>

  The layer name in datasource

-o <dst_datasource_name>

  The path to output linear reference file (linestring datasource)

-on <layer_name>

  The layer name in datasource

-of <field_name>

  The field name for storing the unique values of input lines

-s <step>

  The part size in linear units

-get_pos

  Return linear referenced position for input X, Y

-x <long>

  Input X coordinate

-y <lat>

  Input Y coordinate

-get_coord

  Return point on path for input linear distance

-m <position>

  The input linear distance

-get_subline

  Return the portion of the input path from and to input linear positions.

-mb <position>

  The input begin linear distance

-me <position>

  The input end linear distance

## Examples

### Example 1

This example would create a shapefile (`parts.shp`) containing a data needed for linear referencing (1 km parts):

    ogrlineref -create -l roads.shp -p references.shp -pm dist -o parts.shp -s 1000 -progress