LibreVNA/Software/PC_Application/Util/util.cpp
2022-04-08 21:55:58 +02:00

82 lines
2.3 KiB
C++

#include "util.h"
#include "preferences.h"
#include <QVector2D>
void Util::unwrapPhase(std::vector<double> &phase, unsigned int start_index)
{
for (unsigned int i = start_index + 1; i < phase.size(); i++) {
int d = trunc(phase[i] - phase[i-1]) / M_PI;
if(d > 0) {
// there is larger than a 180° shift between this and the previous phase
phase[i] -= 2*M_PI*(int)((d+1)/2);
} else if(d < 0) {
// there is larger than a -180° shift between this and the previous phase
phase[i] -= 2*M_PI*(int)((d-1)/2);
}
}
}
void Util::linearRegression(const std::vector<double> &input, double &B_0, double &B_1)
{
double x_mean = (input.size() - 1.0) / 2.0;
double y_mean = std::accumulate(input.begin(), input.end(), 0.0) / input.size();
double ss_xy = 0.0;
for(unsigned int i=0;i<input.size();i++) {
ss_xy += input[i] * i;
}
ss_xy -= input.size() * x_mean * y_mean;
int n = input.size() - 1;
double ss_xx = (1.0/6.0) * n * (n + 1) * (2*n + 1) - input.size() * x_mean * x_mean;
B_1 = ss_xy / ss_xx;
B_0 = y_mean - B_1 * x_mean;
}
double Util::distanceToLine(QPointF point, QPointF l1, QPointF l2, QPointF *closestLinePoint, double *pointRatio)
{
auto M = l2 - l1;
auto t0 = QPointF::dotProduct(M, point - l1) / QPointF::dotProduct(M, M);
QPointF closestPoint;
QVector2D orthVect;
if (t0 <= 0) {
orthVect = QVector2D(point - l1);
closestPoint = l1;
t0 = 0;
} else if(t0 >= 1) {
orthVect = QVector2D(point - l2);
closestPoint = l2;
t0 = 1;
} else {
auto intersect = l1 + t0 * M;
orthVect = QVector2D(point - intersect);
closestPoint = intersect;
}
if(closestLinePoint) {
*closestLinePoint = closestPoint;
}
if(pointRatio) {
*pointRatio = t0;
}
return orthVect.length();
}
std::complex<double> Util::SparamToImpedance(std::complex<double> d, std::complex<double> Z0) {
return Z0 * (1.0 + d) / (1.0 - d);
}
double Util::dBmTodBuV(double dBm)
{
double uVpower = 0.000001*0.000001/50.0;
double dBdiff = 10*log10(uVpower*1000);
return dBm - dBdiff;
}
double Util::dBuVTodBm(double dBuV)
{
double uVpower = 0.000001*0.000001/50.0;
double dBdiff = 10*log10(uVpower*1000);
return dBuV + dBdiff;
}