I have a sample array as follows
var arr = [ [ 1373628934214, 3 ], [ 1373628934218, 3 ], [ 1373628934220, 1 ], [ 1373628934230, 1 ], [ 1373628934234,
A simple solution is to use writeFile :
require("fs").writeFile( somepath, arr.map(function(v){ return v.join(', ') }).join('\n'), function (err) { console.log(err ? 'Error :'+err : 'ok') } );