Track size reduction - no input of track size possible

[Reini N]

I'm running Garmin Exchanger on a Nexus7 Tablett.
Unfortunately the reduction of track size is'nt working.
Change of the default track size of "15" is not working. When I change the recommended track size to "500" it will result in a track with 5 trackpoints.

[Reini N]

I now understand that I have to input a factor and not the target value. So a reduction of a track with 941 points with the factor (value) = 0.2 will give  a resulting track with 459 points.
I have no idea how the result depends on the factor.

Who nows this calculation formula ?

[Konstantin Baskakov]

i use Douglas-Peucker algorithm.

from http://phpriot.com/articles/reducing-map-path-douglas-peucker-algorithm/4/