h; i++) {
        var value = this.data[i][1];
        if (value > this.maxValue) {
          this.maxValue = value;
        }
        if (value < this.minValue) {
          this.minValue = value;
        }
      }
    } else {
      // No data exists, so set min/max to NaN
      this.maxValue = Number.NaN;
      this.minValue = Number.NaN;
    }
  };

  /**
   * Adds a new data point to the <code>TimeSeries</code>, preserving chronological order.
   *
   * @param timestamp the position, in time, of this da