////  StDev.cpp//  libraries/shared/src////  Created by Philip Rosedale on 3/12/13.//  Copyright 2013 High Fidelity, Inc.////  Distributed under the Apache License, Version 2.0.//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html// #include "StDev.h" #include <limits>   #include <cmath>#include <cstring> StDev::StDev() :    _sampleCount(0){    reset();} void StDev::reset() {    memset(&_data, 0, sizeof(_data));    _sampleCount = 0;} void StDev::addValue(float v) {    _data[_sampleCount++] = v;    if (_sampleCount == NUM_SAMPLES) _sampleCount = 0;} float StDev::getAverage() const {    float average = 0;    for (int i = 0; i < _sampleCount; i++) {        average += _data[i];    }    if (_sampleCount > 0)        return average / (float)_sampleCount;    else return 0;} float StDev::getStDev() const {    float average = getAverage();    float stdev = 0;    for (int i = 0; i < _sampleCount; i++) {        stdev += powf(_data[i] - average, 2);    }    if (_sampleCount > 1)        return sqrt(stdev / (float)(_sampleCount - 1.0f));    else        return 0;}