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    Javascript Astar

    A* Search / Pathfinding Algorithm in Javascript
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    javascript-astar

    An implementation of the A* Search Algorithm in JavaScript

    See a demo at http://www.briangrinstead.com/files/astar/

    Sample Usage

    If you want just the A* search code (not the demo visualization), use code like this http://gist.github.com/581352

    <script type='text/javascript' src='astar.js'></script>
    <script type='text/javascript'>
        var graph = new Graph([
            [1,1,1,1],
            [0,1,1,0],
            [0,0,1,1]
        ]);
        var start = graph.grid[0][0];
        var end = graph.grid[1][2];
        var result = astar.search(graph, start, end);
        // result is an array containing the shortest path
        var graphDiagonal = new Graph([
            [1,1,1,1],
            [0,1,1,0],
            [0,0,1,1]
        ], { diagonal: true });
    
        var start = graphDiagonal.grid[0][0];
        var end = graphDiagonal.grid[1][2];
        var resultWithDiagonals = astar.search(graphDiagonal, start, end, { heuristic: astar.heuristics.diagonal });
        // Weight can easily be added by increasing the values within the graph, and where 0 is infinite (a wall)
        var graphWithWeight = new Graph([
            [1,1,2,30],
            [0,4,1.3,0],
            [0,0,5,1]
        ]);
        var startWithWeight = graphWithWeight.grid[0][0];
        var endWithWeight = graphWithWeight.grid[1][2];
        var resultWithWeight = astar.search(graphWithWeight, startWithWeight, endWithWeight);
        // resultWithWeight is an array containing the shortest path taking into account the weight of a node
    </script>
    

    A few notes about weight values:

    1. A weight of 0 denotes a wall.
    2. A weight cannot be negative.
    3. A weight cannot be between 0 and 1 (exclusive).
    4. A weight can contain decimal values (greater than 1).

    Original (slower) implementation

    The original version of the algorithm used a list, and was a bit clearer but much slower. It was based off the original blog post. The code is available at: https://github.com/bgrins/javascript-astar/tree/0.0.1/original-implementation.

    The newest version of the algorithm using a Binary Heap. It is quite faster than the original. http://www.briangrinstead.com/blog/astar-search-algorithm-in-javascript-updated Binary Heap taken from http://eloquentjavascript.net/appendix2.html (license: http://creativecommons.org/licenses/by/3.0/)

    Running the test suite

    Build Status

    If you don't have grunt installed, follow the grunt getting started guide first.

    Pull down the project, then run:

        npm install
        grunt
    
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