pttuna: pttuna is yellowfin tuna fishery data from Pella-Tomlinson 1969
Description
pttuna is yellowfin tuna fishery data from Pella-Tomlinson's
(1969) classical paper describing their generalized surplus production
model. This is the same data as contained in the schaef data-set, except
it is extended from 1934 - 1967. Some of the values are slightly
different, and their table rounds off the cpue estimates slightly
differently but the catch and effort figures are theirs. It contains
the year, the catch, the effort, and the cpue (which is just the total
catch divided by the total effort, a ratio estimate). Initial parameter
estimates close to the optimum values for the Schaefer model could be
param <- log(c(r=0.28,K=2100000,Binit=2400000,sigma=0.16)). With this
longer time-series the eventuial MSY estimate was somewhat larger than
when just the schaef data are used.
Arguments
Format
A data.frame of fisheries data
year
the fishing year from 1934 - 1955
catch
the total annual catch, '000s of pounds
effort
the total effort as standard class 4 baitboat fishing days
cpue
the catch '000 pounds per standard class 4 day, a ratio cpue
# NOT RUN { data(pttuna)
pars <- log(c(r=0.25,K=2.1e06,Binit=2.2e06,sigma=0.2))
answer <- fitSPM(pars,pttuna,schaefer=TRUE,maxiter=1000)
outfit(answer,title="Pella-Tomlinson Data",digits=4)
# }