fetchTile-elevation.js

function fetchTile(level, row, col) {
    return this._elevation.fetchTile(level, row, col).then(
      function(data) {
        for (let i = 0; i < data.values.length; i++) {
          if (data.values[i] >= 0) {
            data.values[i] = data.values[i] * 60;
          }
          else {
            data.values[i] = data.values[i] * 40;
          }
        }
        return data;
      }.bind(this));
    }
}