Check Digit Algorithms

[NickSlash]

I am trying to determine what algorithm or method has been used to generate a check digit for a set of data I have.

The data is the 5-Digit price value of a 5-Digit random weight EAN-13 barcode. (i think that's what there called)

I've tried a few different algorithms so far to no avail.

Anyone had experience with check digits and the like and can name a few that I can try?

Below is my less than wonderful testing thing along with the data just in case you want a laugh :/

var set = [
	{ "data": [0,0,4,2,0], "check": 9 },
	{ "data": [0,1,3,2,0], "check": 5 },
	{ "data": [0,0,2,2,5], "check": 9 },
	{ "data": [0,0,2,2,5], "check": 9 },
	{ "data": [0,0,1,5,0], "check": 4 },
	{ "data": [0,0,3,8,0], "check": 7 },
	{ "data": [0,0,2,2,5], "check": 9 },
	{ "data": [0,0,3,6,3], "check": 6 },
	{ "data": [0,0,6,3,0], "check": 6 },
	{ "data": [0,1,6,1,0], "check": 8 },
	{ "data": [0,0,2,2,5], "check": 9 },
	{ "data": [0,1,6,5,0], "check": 3 },
	{ "data": [0,0,3,2,8], "check": 0 },
	{ "data": [0,0,2,2,5], "check": 9 },
	{ "data": [0,1,6,8,0], "check": 6 },
	{ "data": [0,2,9,0,0], "check": 1 },
	{ "data": [0,0,2,2,5], "check": 9 },
	{ "data": [0,0,4,8,0], "check": 4 },
	{ "data": [0,0,9,2,0], "check": 4 },
	{ "data": [0,0,3,2,5], "check": 8 },
	{ "data": [0,2,1,6,3], "check": 7 },
	{ "data": [0,1,6,8,0], "check": 6 },
	{ "data": [0,3,4,8,0], "check": 7 }
];

var algorithm = [
	{
		execute: function(data) {
			var sum = 0
			for (var i=0, l=data.length; i<l; i++) {
				if (i % 2 === 0) {
					sum += data[i]*3;
				} else {
					sum += data[i];
				}
			}
			if (sum % 2 === 0) {
				sum -= Math.floor(sum/10)*10;
			} else {
				sum -= (Math.floor(sum/10)+1)*10;
			}
			return sum;
		},
		name: "ean-13"
	},
	{
		execute: function(data) {
			for (var i=0, l=data.length; i<l; i++) {
				var cd = 0;
				if (i % 2 === 0) {
					if (data[i]*2>10) {
						cd += (data[i]*2)[0]+(data[i]*2)[1];
					} else {
						cd += data[i]*2;
					}
				} else {
					if (data[i]>10) {
						cd += (data[i])[0]+(data[i])[1];
					} else {
						cd += data[i];
					}
				}
			}
			return cd;
		},
		name: "luhn"
	},
	{
		execute: function(data) {
			var wf2m = [0,2,4,6,8,9,1,3,5,7];
			var wf5p = [0,5,1,6,2,7,3,8,4,9];
			var wf5m = [0,5,9,4,8,3,7,2,6,1];
			var wf = [wf5p,wf2m,wf5m,wf5p,wf2m];
			var sum = 0;
			for (var i=0, l=data.length; i<l; i++) {
				sum += wf[i][data[i]];
			}
			if (Math.floor(sum/10) === (sum/10)) {
				sum = Math.floor(sum/10)*10 - sum;
			} else {
				sum = (Math.floor(sum/10)+1)*10 - sum;
			}
			return wf5m[Math.abs(sum)+1];
		},
		name: "gs1tw_5digit",
		note: "http://www.gs1tw.org/twct/web/BarCode/GS1_Section1V6-0_all.pdf"
	}
];

for (var a=algorithm.length; a--;) {
	var p = 0, t = 0;
	console.log("Testing [" + algorithm[a].name + "]");
	for (var i=set.length; i--;) {
		if (Math.abs(algorithm[a].execute(set[i].data)) === set[i].check) {
			p++;
		}
		t++;
	}
	console.log("Test Complete [" + p + "] of [" + t + "] Passed");
}