Implements Pope's Virtual Population Analysis (VPA).
The method returns an object of class
FLVPA class. This extends the
FLAssess class although
FLVPA class currently has the same slots as the
FLAssess class and does not add new ones.
Objects can be created by calls of the form
new("FLVPA", ...) or by calling the
The other arguments to
numeric with default "missing"
Boolean with default TRUE
character string which appended to the desc slot of the object
For the sake of speed, most of the calculations are carried out in C.
Performs a VPA on the FLStock object. Other arguments are fratio, fit.plusgroup and desc, which are described above.
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# use the ple4 data set data(ple4) ple4.test <- ple4 # Remove 0s and set as 1s catch.n(ple4.test)[catch.n(ple4.test)==0] <- 1 # Remove harvest and stock.n values stock.n(ple4.test) <- NA harvest(ple4.test) <- NA # Set Fs in final year and final ages harvest(ple4.test)[,"2001"] <- harvest(ple4)[,"2001"] harvest(ple4.test)["10",] <- harvest(ple4)["10",] # Run the VPA ple4.vpa <- VPA(ple4.test) # Take a look at the harvest plot(harvest(ple4.vpa))