questa è la risposta che mi ha dato il creatori di IPBIKE per quanto riguarda la pendenza differita. Oggi faccio una prova e vi dico come va..leggette attentamente anche se è in inglese mi qui siamo tutti acculturati :) :)
Filtering
There are multiple levels of filtering used on the raw data. For pressure based first multiple readings are averaged to get a reading about 4 times a second if the sensor returns reading quicker than this. The rate readings are returned is very phone dependent.
The first major filter is used to stop the altitude jumping up and down. It's meant to mean you get zero accent and decent when on the flat. It works by remembering the minimum and maximum altitude from the last few readings you can configure how many seconds this window covers from
Settings - Main bike settings - Trip control - Altitude Min Max time. The reported altitude is kept in this range. So if the current reported altitude is < the minimum for the last few readings then the minimum is used as the new reported altitude. If the current altitude is > the max for the last few readings then the maximum is used as the new reported altitude. This system introduces some lag based on the window size but with a suitable size of window you don't get much altitude change when on the flat. When climbing you will get the minimum value from the window when descending the maximum. The default window size for Pressure based is considerable smaller then that for GPS based although there are more samples per second for pressure based. You can configure the display to show the Raw altitude under the altitude list raw altitude. you can also see the range from the window under debug - min max altitude range. The smaller the min max range the better, if its normally small you may want to deduce the window size The range will naturally be bigger when you are going up or down.
The second thing you can vary is how the incline and rate of accent and decent are calculated. Basically the min max filtered altitude is recorded for a number of samples along with the distance and time. These values give you the incline over this period. New entries are added to this moving window if the altitude has changed by more than 0.5m or the distance by 15m or the time by 3 seconds. The size of the window is set in
Settings - Main bike settings - Trip control - Incline records. The smaller the window the more recent the incline and rate of climb readings. The problem is though that if the altitude varies more rapidly than in reality then the more spiky and inaccurate the reported incline and rate of climb. You can display the altitude distance, climb and time used for this calculation with the items under the debug list. If your reported incline is fairly smooth you may want to reduce the window size. If it jumps around erratically then increase the window size.