var rt_plot = new sigplot.Plot(document.getElementById('plot'), {

  autohide_readout: true, // only show the readout when the mouse is over the plot

  autohide_panbars: true // only show panbars when necessary and the mouse is over the plot

})

​

var lyr1 = rt_plot.overlay_array([], {

  file_name: "random1"

});

var lyr2 = rt_plot.overlay_array([], {

  file_name: "random2"

});

​

function update_rtplot() {

  var random1 = [];

  var random2 = [];

  for (var i = 0; i <= 1000; i += 1) {

    random1.push(Math.random());

    random2.push(Math.random() + 1)

  }

​

  rt_plot.reload(lyr1, random1);

  rt_plot.reload(lyr2, random2);

​

}

​

var hdl = window.setInterval(update_rtplot, 500);