Marching squares isobands and isolines ready for using along with d3 maps.
The marching squares algorithm code is taken from the MarchingSquares.js project by Ronny Lorenz, adapted to work with nodejs.
INSTALL
Using nodejs:
npm install raster-marching-squares
From the browser:
Download https://github.com/rveciana/raster-marching-squares/blob/master/build/d3-marching-squares.min.js
USAGE
var intervals = [0, 5, 10, 15, 20, 25, 30, 35, 40];
var bands = rastertools.isobands(rasterData, geoTransform, intervals);
var lines = rastertools.isolines(rasterData, geoTransform, intervals);
- rasterData is a 2D array with the values
- geoTransform is an array following the conventions of the GDAL data model
EXAMPLES
- Isolines with labels: http://bl.ocks.org/rveciana/bef48021e38a77a520109d2088bff9eb
- Simple isobands: http://bl.ocks.org/rveciana/de0bd586eafd7fcdfe29227ccbdcd511