How to use the script

This document is equivalent to the project’s README markdown file and will be added to the repository soon.

Installation and setup

There is no installation required to use this software, but there is a pre-requisite. To use this software you must be able to run node. There is no particular version required, but for your information, the software was developed using version 10.0.8.

The project has a small number of dependencies, which are for parsing input arguments, which is described in the “Usage” section. Dependencies are installed like any other npm project after checking out the repository:

git clone
cd townland-clipper
npm install


After this has completed, the script can be run using the following syntax:

node ./ [--arg=arg_value --arg2=arg2_value ...]

This script cannot produce any output without an input file. The input townland files can be retrieved from

The script is compatible with all variations of the open townland data. Both ungeneralised and all variations of the generalised datasets. It processes one input file per execution and produces a file for each of the Southern counties in a specified target directory.

Required Input arguments

Required arguments:

  • Input GeoJSON - --input=path/to/input.geojson
  • Output directory - --output=target/directory

Optional arguments:

  • Reduce - Halves the precision of the coordinates stored for each townland in the dataset. This reduces file size - --reduce. Defaults to false.
  • Dry run - Everything runs as normal except that no files are written to disk, instead some extra information is printed to the console. - --dryRun. Defaults to false.