Shapefile2Grid

Documentation of how to convert ESRI shapefile to Conveyal grid

1 Install shp2json globally

https://github.com/substack/shp2json

$ npm install -g shp2json

2 Install geobuf globally

https://github.com/mapbox/geobuf

npm install -g geobuf

3 Install node-canvas and its dependencies

In order to install the geobuf-to-grid in the next step, we need to install node-canvas first. https://github.com/Automattic/node-canvas

You can quickly install the dependencies by using the command for your OS:

OS	Command
OS X	brew install pkg-config cairo pango libpng jpeg giflib
Ubuntu	sudo apt-get install libcairo2-dev libjpeg8-dev libpango1.0-dev libgif-dev build-essential g++
Fedora	sudo yum install cairo cairo-devel cairomm-devel libjpeg-turbo-devel pango pango-devel pangomm pangomm-devel giflib-devel
Solaris	pkgin install cairo pango pkg-config xproto renderproto kbproto xextproto
Windows	Instructions on our wiki

El Capitan users: If you have recently updated to El Capitan and are experiencing trouble when compiling, run the following command: xcode-select --install. Read more about the problem on Stack Overflow.

And then install node-canvas

$ npm install canvas

4 Install geobuf-to-grid

https://github.com/conveyal/geobuf-to-grid

$ npm install geobuf-to-grid

5 Convert shapefile zip archives to Geojson using shp2json

Firstly, we need zip the whole shapefile into one zip archives

$ shp2json data.zip data.json

6 Convert Geojson to Geobuf using geobuf

$ json2geobuf data.json > data.pbf

7 Convert Geobuf to grid using geobuf-to-grid

Go to the folder you install geobuf-to-grid, and go to the subfolder named "build" Copy the data.pbf you get from step 6 to this "build" folder And enter the following command

$ node geobuf-to-grid.js --png data.pbf data

The last parameter is the output prefix.

Creates one .grid file for each numeric attribute in the geobuf. If --png is specified, creates log-scaled pngs as well (useful for debugging).

Test environment

• Nodejs 6.9.2
• NPM 3.10.9
• MAC OS 10.12

Converting New Orleans shapefile with 28031 features and 9 fields costs 8 min.