comsir: COM-SIR method

Description Arguments References Examples

Description

Catch-only model with sampling-importance-resampling based on the method described in Vasconcellos and Cochrane (2005).

Arguments

yr

A time series of years associated with the catch

ct

A time series of catch

start_r

A numeric vector of length 2 giving the lower and upper bounds on the population growth rate parameter. This can either be specified manually or by translating resiliency categories via the function resilience.

k_bounds

Minimum and maximum possible stock size at carrying capacity

x_bounds

Minimum and maximum possible x (effort dynamics parameter) values

a_bounds

Minimum and maximum possible a (effort dynamics parameter) values

norm_k

Logical: should k have a normal prior (TRUE) or a uniform prior between mink and maxk (FALSE)?

logk

If logk = TRUE and norm_k = FALSE the prior on k will be an exponentiated form a uniform distribution on a log scale between log(mink) and log(maxk).

nsim

Number of iterations to run before sampling

logistic_model

Logical: if TRUE then the effort dynamics model will be a logistic model. If FALSE then the effort dynamics model will be linear.

n_posterior

Number of posterior samples to draw

obs

Logical: if FALSE then a measurement-error catch model is used. If TRUE then a process-error catch model is used.

effort_bounds

Lower and upper limits on rate of decrease and increase in effort from one time step to the next.

dampen

Should effort dynamics parameters be excluded that may give unstable dynamics?

cv_bounds

Min and max limits on residual error CV around catch

References

Vasconcellos, M., and K. Cochrane. 2005. Overview of World Status of Data-Limited Fisheries: Inferences from Landings Statistics. Pages 1-20 in G. H. Kruse, V. F. Gallucci, D. E. Hay, R. I. Perry, R. M. Peterman, T. C. Shirley, P. D. Spencer, B. Wilson, and D. Woodby, editors. Fisheries Assessment and Management in Data-Limited Situations. Alaska Sea Grant, University of Alaska Fairbanks.

Examples

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x <- comsir(ct = blue_gren$ct, yr = blue_gren$yr, nsim = 1e5,
  n_posterior = 2e3)
par(mfrow = c(1, 2))
hist(x$quantities$bbmsy)
with(x$posterior, plot(r, k))

datalimited/datalimited documentation built on May 14, 2019, 7:44 p.m.