window.onload = () => {
  ocpu.seturl("http://localhost:5656/ocpu/library/cop/R");
  ar = [1, 2, 3, 4, 9, 2, 4, 5];

  let req = ocpu.call("test", {}, function(session){
    $("img").attr("src", session.getFileURL("test.svg"));
  }).fail(() => {
    console.error("Error: " + req.responseText);
  });

  req.always(() => {
    console.log("Success!");
  });

  // if fail
  req.fail(() => {
      alert("R Error!");
  });
}