[atlas] Related to Rip Atlas Credit System

Hi all,

Considering RIPE Atlas credit system,  ping and tracerout unit cost
calculations are tricky. It closely depends on number of packets in
train and size of the packets. Based on [1], predicted cost of a
traceroute measurement with sent packet size of 2040 and 3 as number
of packets (detail arguments are bellow) should be
10*3*(int(2040/1500)+1) = 90 (refer to [1]). However, predicted cost
calculated by RIPE server is 120. After looking at available
JavaScript, we couldn't find the predicted cost calculation. It sounds
like calculation happens on server side and then the the value is
returned. Is it possible to check the server code i.e. is the cost
function calculation on server side publicly available?

Thanks,
Roya Enasfi

[1]: https://atlas.ripe.net/docs/credits

Details for a traceroute measurement : (Per result: 120.0 credits,
Estimated total cost: 120 credits)
Arguments: (Interval: 900 seconds, Resolve on probe: No, First hop: 1,
#packets: 3, Don't fragment: True, Max hops: 32, Tcp: True,Paris: 16,
Timeout resp.(ms): 4000, Port: 80, Size: 2040)