Map a 2D array onto an underlying contiguous 1D array.

Matrix.js

Matrix = (function(){
	function id(){return this;}
	function _set(idx,src){this[idx]=src;}
	function _get(idx){return this[idx];}
	
	Array.prototype.subarray = function(start,end){
		var j,row = {};
		for(j=0;start<end;j++,start++){
			Object.defineProperty(row,j,{
				set:_set.bind(this,start),
				get:_get.bind(this,start)
			});
		}
		return row;
	};
	
	return function(array,r,c){
		var i,offset,j,buffer,len;
		if(!c){
			c = r;
			r = array;
			array = Int32Array;
		}
		len = c*r;
		buffer = (typeof array === 'function')?
			new array(len):array;
		if(len > buffer.length && !(buffer instanceof Array)){
			throw new Error("Matrix doesn't fit in given array.");
		}
		for(offset=i=0;i<r;i++,offset+=c){
			this.__defineGetter__(i,id.bind(buffer.subarray(offset,offset+c)));
		}
	
		this.length = len;
		this.rows = r;
		this.cols = c;
		this.array = buffer;
		return this;
	}
}());

/*
//Construct a matrix referencing a Typed Array
new Matrix(5,5); //defaults to Int32
new Matrix(Uint8Array,5,5);
new Matrix(new Uint8Array(25),5,5);
//throw an error
try{
	new Matrix(new Uint8Array(20),5,5);
}catch(e){console.log(e);}

//Map a matrix onto a flat JS array
new Matrix([1,2,3,4,5,6,7],5,5);
new Matrix(Array,5,5);
*/