Standard Deviation Population?
I need to rewrite the SQL Server's functionSTDEVP in Java. I did the normal standarddeviation (STDEV) as it is widely described on the net:
/**
* Get the standard deviation of a list of numbers.
*
* @param numbers List of numbers.
* @return Standard deviation of <i>numbers</i>.
*/
staticpublicdouble getStandardDeviation(final List<Number> numbers){
double result = 0.0;
if (numbers !=null && numbers.size() > 0){
int count = 0;
double sum = 0.0;
double sumSquare = 0.0;
for (final Number n : numbers){//for each number
count++;
sum += n.doubleValue();
sumSquare += n.doubleValue() * n.doubleValue();
}//next number
finaldouble average = sum / count;
result = Math.sqrt((sumSquare / count) - (average * average));
}
return result;
}//getStandardDeviation()
But how does this "population" version differ from the standard version?
