How to remove some points in chartjs

Question

I have to hide / remove all data points except the second last point as shown in this image I have searched everywhere but couldn't find the proper solution to achieve this.

myChart.datasets[0].points[0].display = false;
legStretchtCtx.update();

Above snippet is for Chart.js Version 1.0 but I'm using Chart.js Version: 2.7.1 . I have used this snippet but its giving an error:

Cannot read property '0' of undefined

var legStretchtCtx = document.getElementById("leg-stretch-chart");
          // var legStretch =
          var myChart = new Chart(legStretchtCtx, {
              type: 'line',
              data: {
                  labels: ["Day 1", "Day 2", "Day 3", "Day 4", "Day 5", "Day 6","Day 7"],
                  datasets: [{
                      label: 'Leg Stretch',
                      data: [3, 4, 5, 4, 3, 3.5, 3.5],
              				backgroundColor:"#70d6db",
                      borderColor: ["#70d6db"],
                      borderWidth: 4,
                      pointBackgroundColor: "#fff",
                      pointRadius: 8,
                      pointHoverRadius: 8,
      				        pointHoverBackgroundColor: "#0ba8b0",
                      pointHoverBorderColor: "#26c1c9",
      				        pointBorderColor:"#26c1c9"

                  }]
              },
              options: {
                  legend: {
                      display: false,
                      labels: {
                          display: true
                      }
                  },
      			responsive:true,
                  scales: {
                      xAxes: [{
                          gridLines: {
                              display: false,
                              drawBorder:false,

                          },
                          ticks: {
                              display: false,
                              fontFamily: "Montserrat",
                              fontColor: "#2c405a",
      						fontSize: 12
                          }
                      }],
                      yAxes: [{
                          gridLines: {
                              display: false,
                              drawBorder:false,

                          },
                          ticks: {
      						display: false,
      						fontFamily: "Montserrat",
                              fontColor: "#2c405a",
                             	fontSize: 12,
      						stepSize:1,
                              min: 0,
                              max: 10,
      					}

                      }]
                  }
              }
          });

<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.7.1/Chart.bundle.js"></script>
<div class="chart-container">
  <div class="leg-stretch-chart-inner">
    <canvas id="leg-stretch-chart" width="100%" height=""></canvas>
  </div>
</div>

Answer 1

First, change pointRadius to array:

pointRadius: [8, 8, 8, 8, 8, 8, 8]

Then, you have to rewrite this array with specific values for each point (in our case, the second last pont) and update:

$("#btnRemovePoints").click(function()
{
    //change the radius of every point except one
    myChart.data.datasets[0].pointRadius = [0, 0, 0, 0, 0, 8, 0];
    myChart.update();
});

More details in this fiddle: https://jsfiddle.net/s7m1961t/