alkorithm-two.js

/*
  Input Data Structure:
  [
    { 
      _id: "id",
      date: "1-May-12",
      close: 68.13,
      open: 34.12 
    },
    
    ...
  ]
*/

var arr = ['close', 'open'];
var parsedArr = [];

for (var i = 0; i < arr.length; i += 1) {
  if (!parsedArr[i]) {
    parsedArr[i] = [];
  }
  parsedArr[i] = data.map(
    function (d) {
      return { value: d[arr[i]], date: d.date }
    }
  );
}

/*
  Needed output Data structure:
  [
    [{date: "date", value: "value"}, ...],
    [{date: "date", value: "value"}, ...]
  ]
*/