Value Goals

var decimal_data = [];

for (var x = 0; x <= 360; x += 10) {

  decimal_data.push({

    x: x,

    y: Math.sin(Math.PI * x / 180).toFixed(4)

  });

}

window.m = Morris.Line({

  element: 'graph',

  data: decimal_data,

  xkey: 'x',

  ykeys: ['y'],

  labels: ['sin(x)'],

  parseTime: false,

  goals: [-1, 0, 1]

});