docs: function resizePolar(polar, polarModel, api) {
      var center = polarModel.get('center');
      var width = api.getWidth();
      var height = api.getHeight();
  
      polar.cx = parsePercent(center[0], width);
      polar.cy = parsePercent(center[1], height);
  
      var radiusAxis = polar.getRadiusAxis();
      var size = Math.min(width, height) / 2;
      var radius = parsePercent(polarModel.get('radius'), size);
      radiusAxis.inverse
          ? radiusAxis.setExtent(radius, 0)
          : radiusAxis.setExtent(0, radius);
  }