Java Utililty Methods List Mean

double calculateStDev(List values, double mean)
calculate St Dev

int listSize = values.size();
Double sumOfDiffSquared = 0.0;
for (Double value : values) {
 double diffFromMean = value - mean;
 sumOfDiffSquared += ((diffFromMean * diffFromMean) / (listSize - 1));
double variance = sumOfDiffSquared;
return Math.sqrt(variance);
...

double computeMean(List fs)
compute Mean

Double sum = 0.0;
for (Number d : fs)
 sum += d.doubleValue();
return sum / fs.size();

double geometricMean(List vals, double replacement)
Return the geometric mean of the absolute values of elements

int numVals = vals.size();
double product = 1.0;
for (int i = 0; i < numVals; i++) {
 Double val = (Double) vals.get(i);
 double dval = (val.isNaN()) ? replacement : val.doubleValue();
 if (dval == 0.0) {
 dval = replacement;
 product *= Math.abs(dval);
return (Math.pow(product, 1.0 / (double) numVals));

double getHMean(List harray)
Compute mean for a given set of numbers

Iterator<Number> it = harray.iterator();
double vsum = 0, mean = 0;
int count = 0;
while (it.hasNext()) {
 Number vl = it.next();
 double val = vl.doubleValue();
 vsum += val;
 count++;
...

double getMean(List data)
get Mean

double mean = 0;
final int n = data.size();
if (n < 2) {
 return Double.NaN;
for (int i = 0; i < n; i++) {
 mean += data.get(i);
mean /= n;
return mean;

double getMean(List list)
get Mean

double sum = 0.0;
for (double value : list) {
 sum += value;
return sum / list.size();

double getStandardDeviation(double meanValue, List values)
get Standard Deviation

if (values.isEmpty()) {
 return -1.0;
double sum = 0.0;
for (Double value : values) {
 sum += Math.pow(meanValue - value, 2.0);
return Math.sqrt(sum / (values.size() - 1));
...

Double getStandardDeviation(List doubles, Double mean)
get Standard Deviation

double sum = 0;
int i = 0;
for (Double d : doubles) {
 if (d == null)
 continue;
 sum += (d - mean) * (d - mean);
 i++;
return i == 0 ? null : Math.sqrt(sum / i);

double getStandardDeviationOfMean(List doubles)
get Standard Deviation Of Mean

return getStandardDeviation(doubles, getMean(doubles));

double mean(double[] list)
mean

return sum(list) / list.length;