static-interval-tree
v1.3.0
Published
interval tree, for fast overlapping interval queries
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Static interval tree
A very simple library for finding overlapping intervals in one dimension.
The intervals are indexed using an augmented balanced binary search tree. The search tree is bulk-loaded by sorting. There's no support for adding/removing intervals.
Intervals are assumed to be over integers. Coordinates can be closed [start, end], or half-open [start, end).
Query time with the index should be O(log n + k), (k being number of matches returned) rather than the O(n) required for a brute-force search.
Work in progress. Might be useful for drawing genomic data.
Methods
var {index, matches} = require('static-interval-tree');
// index(intervals :: [{start, end, ...}, ...]) :: interval-tree
var idx = index([{start: 10, end: 12, id: 1}, {start: 21, end: 30: id: 2}]);
// matches(interval-tree, pos :: {start, end}) :: [{start, end, ...}, ...]
var overlapping = matches(idx, {start: 12, end: 22});
// => [{start: 10, end: 12, id: 1}, {start: 21, end: 30: id: 2}]
// matching half-open coords, [start, end)
// matches01(interval-tree, pos :: {start, end}) :: [{start, end, ...}, ...]
var overlapping = matches01(idx, {start: 12, end: 22});
// => [{start: 21, end: 30: id: 2}]
Note that building the tree is independent of the choice of closed or half-open coordinates, however you should use match01 if your coordinates are half-open. The intervals in the tree and the interval for query must use the same coordinate system, either closed or half-open.
Build
The build is based on npm and webpack.
- Ensure that git and node are installed
- On OSX, install brew http://brew.sh/
brew install git
brew install node
git clone https://github.com/acthp/static-interval-tree.git
cd static-interval-tree
npm install
npm start
- browse to http://localhost:8080/webpack-dev-server/
Lint
Use npm run lint
to run the lint rules. We lint with eslint and babel-eslint.
References
- http://blog.keithcirkel.co.uk/how-to-use-npm-as-a-build-tool/
- http://webpack.github.io/
- http://www.youtube.com/watch?v=VkTCL6Nqm6Y