chart.js: hide specific ticks in y-axis and hide all x-axis grid line

Question

Edit

I'm using charts.js library and i wanted to know if it's possible to hide specific ticks from my y-axis, for example, i have defined ticks's min:0 and max:100 and it shows all the values in multiples of ten from 0 to 100, but i want to display only 0, 50 e 100. (this is solved)

Another problem is that i wanted to remove all x-axis' gridline but method "gridLines.display : false" doesn't hide the first vertical line on the beginning of the chart, just hides the others.

this is what i want to look like: http://i.stack.imgur.com/GryIo.png

Script

        var humdays = document.getElementById("charthumdays");
        var humdaysChart = new Chart(humdays, {
        type: 'bar',
        data: {
            labels: ["15 mar", "16 mar", "17 mar", "18 mar", "19 mar", "20 mar", "21 mar"],
            datasets: [{
                label: "humidity",                
                data: [60, 20, 30, 50, 60, 80, 90],
                backgroundColor: "#D9B090",
                hoverBackgroundColor: 'rgba(217,176,144,0.8)'


            }]
        },
        options: {

            scales: {

               xAxes : [{


                    gridLines : {
                         display : false
                    }

               }],

                yAxes: [{

                    ticks: {
                        min:0,
                        max:100

                    }
                }]
            }
        }
    });

    humdaysChart.options.legend.display = false;

Answer 1

Use the afterBuildTicks option for the scales/yAxes

yAxes: [{

  ticks: {
    min: 0,
    max: 100

  },
  afterBuildTicks: function(humdaysChart) {    
    humdaysChart.ticks = [];
    humdaysChart.ticks.push(0);
    humdaysChart.ticks.push(50);
    humdaysChart.ticks.push(100);    
  }
}]

or you can also use 'stepSize'

   yAxes: [{

        ticks: {
            min:0,
            max:100,
            stepSize:50

        }
    }]

http://jsfiddle.net/Lehuga5o/