/**
* Implementation of the virtual <code>update(Observable, Object)</code> method of the <code>
* Observer</code> interface. This method will be called automatically from an <code>Observable
* </code> object within its <code>notifyObservers()</code> method. <br>
* If no Object (a<code>null</code> value) is passed as arg, the actual value of the ValueSupplier
* will be fetched with the <code>value()</code> method of the ValueSupplier. Otherwise it is
* expected that the actual value is passed in the Object arg.
*
* @param o java.util.Observable : The Observable calling this method within its own <code>
* notifyObservers()</code> method.
* @param arg Object : The Object with which this <code>TallyRunning</code> is updated. Normally a
* double number which is added to the statistics or <code>null</code>.
*/
public void update(Observable o, Object arg) {
if (o == null) // null was passed instead of an Observable
{
sendWarning(
"Attempt to update a TallyRunning with no reference to an "
+ "Observable. The actual value of '"
+ getValueSupplier().getName()
+ "' will be fetched and processed anyway.",
"TallyRunning: " + this.getName() + " Method: update (Observable " + "o, Object arg)",
"The passed Observable: o in this method is only a null pointer.",
"The update()-method was not called via notifyObservers() from an "
+ "Observable. Who was calling it? Why don't you let the Observable do"
+ " the work?");
}
super.update(o, arg); // call the update() method of Tally
long obs = getObservations();
double lastVal = getLastValue();
int index = (int) ((obs - 1) % this._n);
this._sumLastN += lastVal - this._valuesLastN[index];
this._sumSquareLastN += lastVal * lastVal - this._valuesLastN[index] * this._valuesLastN[index];
// note: in case obs < n, this.valuesLastN[index] will be zero
this._valuesLastN[index] = lastVal;
}
/**
* Updates this <code>TallyRunning</code> object by fetching the actual value of the <code>
* ValueSupplier</code> and processing it. The <code>ValueSupplier</code> is passed in the
* constructor of this <code>TallyRunning</code> object. This <code>update()</code> method
* complies with the one described in DESMO, see [Page91].
*/
public void update() {
super.update(); // call the update() method of Tally
long obs = getObservations();
double lastVal = getLastValue();
int index = (int) ((obs - 1) % this._n);
this._sumLastN += lastVal - this._valuesLastN[index];
this._sumSquareLastN += lastVal * lastVal - this._valuesLastN[index] * this._valuesLastN[index];
// note: in case obs < n, this.valuesLastN[index] will be zero
this._valuesLastN[index] = lastVal;
}
/** Resets this TallyRunning object by resetting all variables to 0.0 . */
public void reset() {
super.reset(); // reset the Tally, too.
this._sumLastN = this._sumSquareLastN = 0.0;
}
