gistfile1.txt

global.data = [
  {
    x: "" ,
    y: "" ,
    'type':'scatter',
    'mode':'lines+markers',
    stream: {token: 'thetoken'}
  }
  ];


var data =  [
	  {
	    x: msg.x,
	    y: msg.y,
      'type':'scatter',
      'mode':'lines+markers',
      stream: {token: 'thetoken'}
	  }
	];


var i = 0;
global.data.push(x, data[i].y);

console.log(global.data);

output: 
[ { x: '',
    y: '',
    type: 'scatter',
    mode: 'lines+markers',
    stream: { token: 'thetoken' } },
  '2017-04-25 20:27:04.426',
  3.4928,
  '2017-04-25 20:27:06.147',
  1.598,
  '2017-04-25 20:27:07.992',
  5.8,
  '2017-04-25 20:27:10.457',
  5.0345,
  '2017-04-25 20:27:11.275',
  3.09275 ]