69 lines
1.6 KiB
C++
Executable File
69 lines
1.6 KiB
C++
Executable File
/*==============================================================================
|
|
|
|
Copyright 2018 by Roland Rabien, 1998 David C. Swaim
|
|
For more information visit www.rabiensoftware.com
|
|
|
|
==============================================================================*/
|
|
|
|
LinearRegression::LinearRegression()
|
|
{
|
|
}
|
|
|
|
LinearRegression::LinearRegression (Array<juce::Point<double>> points)
|
|
{
|
|
for (auto p : points)
|
|
addPoint (p);
|
|
|
|
calculate();
|
|
}
|
|
|
|
void LinearRegression::clear()
|
|
{
|
|
n = 0;
|
|
sumX = 0;
|
|
sumY = 0;
|
|
sumXsquared = 0;
|
|
sumYsquared = 0;
|
|
sumXY = 0;
|
|
|
|
a = 0;
|
|
b = 0;
|
|
coefD = 0;
|
|
coefC = 0;
|
|
stdError = 0;
|
|
}
|
|
|
|
void LinearRegression::addPoint (juce::Point<double> pnt)
|
|
{
|
|
n++;
|
|
sumX += pnt.getX();
|
|
sumY += pnt.getY();
|
|
sumXsquared += pnt.getX() * pnt.getX();
|
|
sumYsquared += pnt.getY() * pnt.getY();
|
|
sumXY += pnt.getX() * pnt.getY();
|
|
}
|
|
|
|
void LinearRegression::calculate()
|
|
{
|
|
if (haveData())
|
|
{
|
|
if (std::fabs (n * sumXsquared - sumX * sumX) > DBL_EPSILON)
|
|
{
|
|
b = (n * sumXY - sumY * sumX) / (n * sumXsquared - sumX * sumX);
|
|
a = (sumY - b * sumX) / n;
|
|
|
|
double sx = b * (sumXY - sumX * sumY / n);
|
|
double sy2 = sumYsquared - sumY * sumY / n;
|
|
double sy = sy2 - sx;
|
|
|
|
coefD = sx / sy2;
|
|
coefC = std::sqrt (coefD);
|
|
stdError = std::sqrt(sy / (n - 2));
|
|
}
|
|
else
|
|
{
|
|
a = b = coefD = coefC = stdError = 0.0;
|
|
}
|
|
}
|
|
}
|