Ticket #1077 (new NOT SET)
Ascendency and overhead (but not capacity) calculated on exports are wrong
| Reported by: | albertobarausse | Owned by: | |
|---|---|---|---|
| Priority: | normal | Milestone: | NOT SET |
| Component: | Network Analysis plug-in | Version: | 6.3.1 |
| Severity: | major | Keywords: | Ascendancy |
| Cc: |
Description
I have found this bug in the ascendency calculations in EwE (both version 5 and 6).
Ascendency and overhead (but not capacity) calculated on exports are wrong. This bug is only present if your model has (not-negligible) emigration flows for one or more groups. To begin with, exports are calculated as the sum of catches and emigration, the latter includes exports from the system for detritus, which is = (1-EEdetritus)*(flow into detritus). Based on such flows, I have verified ascendency calculations based on equations found in Latham II (2006) Network flow analysis algorithms. Ecological Modelling 192: 586-600. Capacity (flowbits) is correctly calculated in EwE, but there is clearly a problem with calculation of ascendency, or overhead, or both: their sum is not equal to capacity (and can be very different), unlike it should be. I have not been able to find out where the calculations are wrong, but there is certainly a bug...
