/** ** Update min/max temperatures */
 private void _updateMinMaxTemperature() {
   this.minTempC = 9999.0;
   this.maxTempC = -9999.0;
   for (Temperature T : this.tempList) {
     double tempC = T.getTemperatureC(); // temperature guaranteed valid
     if (tempC < this.minTempC) {
       this.minTempC = tempC;
     }
     if (tempC > this.maxTempC) {
       this.maxTempC = tempC;
     }
   }
 }
 /** ** Adds the specified temperature to this data set */
 public boolean addTemperature(Temperature T) {
   if (Temperature.isValid(T)) { // valid timestamp and temperature
     this.tempList.add(T);
     double tempC = T.getTemperatureC();
     if (tempC < this.minTempC) {
       this.minTempC = tempC;
     }
     if (tempC > this.maxTempC) {
       this.maxTempC = tempC;
     }
     return true;
   } else {
     return false;
   }
 }