Merge pull request #473 from bilke/fix-interpolation

Fixed wrong support point index at start and end point.

MathLib/InterpolationAlgorithms/PiecewiseLinearInterpolation.cpp

@@ -58,10 +58,10 @@ double PiecewiseLinearInterpolation::getValue(double pnt_to_interpolate) const
 {
 	// search interval that has the point inside
 	std::size_t interval_idx(std::numeric_limits<std::size_t>::max());
-	if (pnt_to_interpolate < _supp_pnts.front()) {
+	if (pnt_to_interpolate <= _supp_pnts.front()) {
 		interval_idx = 0;
 	} else {
-		if (_supp_pnts.back() < pnt_to_interpolate) {
+		if (_supp_pnts.back() <= pnt_to_interpolate) {
 			interval_idx = _supp_pnts.size() - 2;
 		} else {
 			auto const& it(std::lower_bound(_supp_pnts.begin(), _supp_pnts.end(), pnt_to_interpolate));