$("#radarDLBut").click(function(){
var data = [displayData["radar_chart"]["r_label"],displayData["radar_chart"]["r_default"]]; 
var csvContent = "data:text/csv;charset=utf-8,\ufeff";
if (window.navigator.msSaveOrOpenBlob) {
  csvContent = "\ufeff";
}
data.forEach(function(infoArray, index){
  dataString = infoArray.join(",");
  csvContent += index < data.length "\n" : dataString;
});
if (window.navigator.msSaveOrOpenBlob) {
  // if browser is IE
  var blob = new Blob([decodeURIComponent(encodeURI(csvContent))],{
 type: "text/csv;charset=utf-8;"
  });
  navigator.msSaveBlob(blob, 'subject.csv');
}else{
  var encodedUri = encodeURI(csvContent);
  var link = document.createElement("a");
  link.setAttribute("href", encodedUri);
  link.setAttribute("download", "subject.csv");
  document.body.appendChild(link);
  link.click();
}
});