salmon.rate {UsingR} | R Documentation |
The Ricker model is used to model the relationship of recruitment of a salmon species versus the number of spawners. The model has two parameters, a rate of growth at small numbers and a decay rate at large numbers. This data set is simulated data for 83 different recordings using parameters found in a paper by Chen and Holtby.
data(salmon.rate)
The format is: 83 numbers on decay rates.
The Ricker model for recruitment modeled by spawner count
R_t =
S_t e^{a - bS_t}
The paramter b
is a decay rate
for large values of S
. In the paper by Chen and Holtby, they
studied 83 datasets and found that b
is log-normally distributed. The
data is simulated from their values to illustrate a log normal
distribution.
These values are from D.G. Chen and L. Blair Holtby, “A regional meta-model for stock recruitment analysis using an empirical Bayesian approach”, found at https://iphc.int/.
data(salmon.rate)
hist(log(salmon.rate))