agesurvcl: Age-Based Survival and Mortality Estimators for Cluster Sampling
Description
Calculates the survival and mortality estimators of Jensen (1996) where net hauls are treated as samples
Usage
agesurvcl(age = NULL, group = NULL, full = NULL, last = NULL)
Arguments
age
the vector of ages. Each row represents the age of an individual.
group
the vector containing variable used to identify the sampling unit (e.g., haul). Identifier can be numeric or character.
full
the fully-recruited age.
last
the maximum age to include in the calculation. If not specified, the oldest age is used.
Value
Matrix containing estimates of annual mortality (a), annual survival (S), and instantaneous total mortality (Z) and
associated standard errors.
Details
The individual age data are tabulated and subsetted based on full and last. The calculations follow Jensen(1996).
If only two ages are present, a warning message is generated.
References
Jensen, A. L. 1996. Ratio estimation of mortality using catch curves. Fisheries Research 27: 61-67.