line-interpolate-points

line interpolate points

A Node module that interpolates the coordinates of any number of equidistant points along a line composed of one or more line segments. It's particularly useful for GIS applications, and is analogous to the PostGIS ST_LineInterpolatePoint() and Python Shapely's shapely.geometry.LineString.interpolate(). Here's an example of a number of points interpolated over a multi-segment line:

the api

The module exports a single function, interpolateLineRange( ctrlPoints, number ); ctrlPoints is an array of 2D point objects, like [ { x: 5, y: 10 }, { x: 7, y: 10 }, { x: 14, y: 13 } ], while number is the number of points to interpolate (the endpoints included).

> var interpolateLineRange = require( 'line-points-interpolator' )
> interpolateLineRange( [ { x: 3, y: 10 }, { x: 4, y: 10 } ], 2 )
[ { x: 3, y: 10 },
  { x: 4, y: 10 } ]
> interpolateLineRange( [ { x: 3, y: 10 }, { x: 4, y: 10 } ], 4 )
[ { x: 3, y: 10 },
  { x: 3.3333333333333335, y: 10 },
  { x: 3.666666666666667, y: 10 },
  { x: 4, y: 10 } ]

Install Dev Dependencies

$ npm install

Contributing

Please fork and pull request against upstream master on a feature branch. Pretty please: provide unit tests and script fixtures in the test directory.

Running Unit Tests

$ npm test

Continuous Integration

Travis tests every release against node version 0.10