Description Usage Arguments Value
Calculates the catch per station.
Similar as afli.per.stod
in the fjolst-package except returns
abundance and biomass per length class, as well as abundance less than
and biomass greater than a given length class.
1 2 | catch_by_station(Stations, Lengths, lwcoeff = c(0.01, 3), std = c("none",
"towlength", "areaswept"), std.towlength = 4, std.towwidth = 17)
|
Stations |
A dataframe with station information. Required columns are id (unique station id), year, towlength and strata (the strata identifyer). |
Lengths |
A dataframe with length frequency measurements. Required columns are id (station id), length (the length class) and n (the number of fish measured) where the latter are the "raised" numbers. |
lwcoeff |
A vector of length 2, containing parameter a and b of the length weight relationship. |
std |
Character specifying standardization. Valdi character are "none", "towlength" or "areaswept". |
std.towlength |
Standard towlength in nautical miles. Default is 4 (not used if std = "none"). |
std.towwidth |
Standard width of trawl in meters. Default is 17 (only used if std = "areaswept"). |
A dataframe containing the follow columns ..
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