Knowledge Base

Minimum Distance Moved Methods

In both cases, all five samples are selected for analysis. However, some samples have been "moved" to a previous sample in such a way that their own value of distance moved is zero.

Direct

The program calculates the shortest distance between a sample and the next (AB, dashed line). If this distance is shorter than the threshold distance MDM, sample B is set to sample A. Then the program calculates the distance to the second next sample (AC), etc. until it finds a segment (AD) longer than MDM. Samples B and C are both set to sample A. This procedure is then repeated up to the end of the track.

With the Direct method, samples B and C overlap with A, and E with D.

Along the Path

EthoVision XT calculates the distance between a sample and the next (AB, dashed line). If this distance is shorter than the distance threshold, sample B is set to sample A. Then the program calculates the cumulative distance along the path to the second next sample (AB + BC, etc.). In this example, sample B is set to sample A. However, the distance AB + BC is greater than MDM, so C stays in its place. Next, sample D is set to sample C because CD < MDM. However, CD + DE is longer than MDM, so sample E stays in its place. The procedure is repeated up to the end of the track.

With Along the Path, sample B overlaps with A, and D with C.

The resulting total distance moved can therefore differ depending on which option is chosen.

Source: EthoVision XT 19 Help - Smooth the Tracks, Noldus Information Technology