Calculate for each track, its fractal dimension Katz & George (1985) define fractal dimension (D) as log(n) / (log(n) + log(d/L)) where n is the number of steps, d is the longest of all possible point-to-point distances and L is the cumulative length of the track. D is ~1 for directed trajectories, ~2 for confined and ~3 for subdiffusion Here we calculate this and store D (called fd) and d (called wide) for return. Note that this method does not take into account gaps in the track. For a track with many gaps, n will be lowered.
calculateFD(dataList)list of a data frame (must include at a minimum - trace (track ID), x, y and frame (in real coords)) and a calibration data frame
data frame
xmlPath <- system.file("extdata", "ExampleTrackMateData.xml", package="TrackMateR")
tmObj <- readTrackMateXML(XMLpath = xmlPath)
#> Units are: 1 pixel and 0.07002736 s
#> Spatial units are in pixels - consider transforming to real units
#> Collecting spot data. Using 4 cores
#> Matching track data...
#> Calculating distances...
tmObj <- correctTrackMateData(dataList = tmObj, xyscalar = 0.04)
#> Correcting XY scale.
fdDF <- calculateFD(dataList = tmObj)