Fit catch data to several sizeselectivity models
Description
Compare the fit of catch data to several sizeselectivity
models fitted by fit.catch
.
Usage
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19  fit.catch.compare(catch, perimeter.factor = 1, tol = 1e08, omega0 = 0.1,
effort = NULL)
## S3 method for class 'fit.catch.compare'
deviance(object, ...)
## S3 method for class 'fit.catch.compare'
AIC(object, ..., k = 2)
## S3 method for class 'fit.catch.compare'
print(x, digits = max(3, getOption("digits")  3),
...)
## S3 method for class 'fit.catch.compare'
plot(x, y, ...)
## S3 method for class 'fit.catch.compare'
summary(object, l = get.lens(object),
m = get.mesh(object), ...)

Arguments
catch 
an object of class 
perimeter.factor 
Factor by which to multiply the inputted mesh sizes to obtain mesh perimeters. 
x 
an object of class 
object 
an object of class

y 
not used. only for consistency with S3 plot method. 
k 
not used. only for consistency with default S3 method. 
tol 
tolerance used to decide on whether fitted values are numerically zero. used to correct AIC values. this correction depends on sample size, and the standard way to calculate sample size is as the number of mesh sizes times the number of fish length categories and then to subtract from this number the number of zero fitted counts 
omega0 
initial value for the tangle parameter 
digits 
number of digits to round to 
effort 
TODO (sorry!) 
... 
additional arguments to be passed 
l 
Lengths 
m 
Mesh sizes 
Value
An object of class fit.catch.compare
with
components:
norm.loc fit.catch
object using the norm.loc
selection curve
norm fit.catch
object using the norm
selection curve
lognorm fit.catch
object using the lognorm
selection curve
gamm fit.catch
object using the gamm
selection curve
inv.gau fit.catch
object using the inv.gau
selection curve
Author(s)
Steve Walker
References
J.F. Bromaghin (2005) A versatile net selectivity model, with application to Pacific salmon and freshwater species of the Yukon River, Alaska. Fisheries Research 74: 157168.
R.B. Millar & R.J. Fryer (1999) Estimating the sizeselection curves of towed gears, traps, nets and hooks. Reviews in Fish Biology and Fisheries 9: 89116.
Examples
1 2 3 4  np < make.catch(north.pike$MESH, north.pike$FLEN)
fms < fit.catch.compare(np)
fms
plot(fms)
