A method and an apparatus for determining at least one smoothed data point (tk, sk) within a stream of data points {ti, si} with 1≤；i≤；z, k<；z is disclosed. Herein, the stream of data points {ti, si} is consecutively acquired in a manner that a data point (ti, si) is acquired after an acquisition of a preceding data point (ti-1, si−；1), wherein each data point (ti, si) comprises a valid value or an invalid value or a missing value for the signal si at a time ti. Herein, the signal si at the time ti comprises physical, chemical, biological, environmental, and/or technical data acquired by means of a technical set-up. According to the method, a set of data points is provided, wherein for each smoothed data point (tk, sk) a smoothing set is created. For each smoothed data point (tk, sk), trailing data resulting from large gaps are removed until it is verified whether the smoothing set comprises a minimal number of data points. Thereafter, for each smoothed data point (tk, sk) an initial slope set is calculated, on which at least one exponential smoothing is applied, in which cause an at least once modified slope set is determined. By integrating the at least once modified slope set, a value for the smoothed data point (tk, sk) is determined and returned. The method provides a good degree of smoothing without introducing any lag time and with minimal distortions, and is capable of reporting derivatives for the set of smoothed data points at the same time. The method is particularly suited in real-time or nearly real-time measurements which may comprise large gaps within the stream of data points.
