2015-06-18, 17:14

(2015-06-14, 21:35)Egon Wrote: Hi Folks,Hi Egon,

I have changed the computation of the effectivity shown in the station list at blitzortung.org (this is not the efficiency of lightningmaps.org you have discussed above). The time period is 1 hour. I need the following notations to explain the computation.

Strikes (x,s) = number of strikes in a rage of x km to station s

Hits (x,s) = number of strikes in a range of x km to station s at that station s was involved

Signals (s) = number of signals of station s

Strikes = total number of computed strikes of the region to that the station sends data

min (x,y) = minimum of x and y

Then we have:

Effectivity_50 = Hits (s,50) / Strikes (s,50) * min (Strikes / Signals (s), Signals (s) / Strikes)

Effectivity_500 = Hits (s,500) / Strikes (s,500) * min (Strikes / Signals (s) /, Signals (s) / Strikes)

Effectivity_5000 = Hits (s,5000) / Strikes(s,5000) * min (Strikes / Signals (s), Signals (s) / Strikes)

If a denominator is zero, the effectivity is zero.

This is the old effectivity value multiplied by the factor min (Strikes / Signals(s), Signals(s) / Strikes) to consider also the strikes/signals relation (and to punish the stations that send a lot of trash ).

The effectivity should only be considered as a relative measure of the performance, although a value of 1 can be obtained.

Much fun,

Egon

I get the general idea of the new computation (quite hard for someone one who sucs at maths...) But i am trying to figure out what the Y in "min (x,y) = minimum of x and y" stands for. I thought i'd just ask .

Gerhard