alkss: Sample Size Determination for Age Subsampling
Description
Calculates sample sizes for age subsampling assuming a two-stage random sampling design with
proportional or fixed allocation.
Usage
alkss(x, lss = NULL, cv = NULL, allocate = 1)
Arguments
x
a data frame containing an age-length key (similar to Table 8.3 on page 307 of Quinn and Deriso (1999)).
The first column must contain the length intervals as numeric labels (no ranges), the second column must
contain the number of samples with
lss
the sample size for length frequency
cv
the desired coefficient of variation
allocate
the type of allocation: 1=proportional, 2=fixed.
Value
labellist element containing the summary of input criteria
nlist element containing the sample size estimates for each age
Details
If individual fish from catches are sampled randomly for lengths and then are further subsampled
for age structures, Quinn and Deriso (1999: pages 306-309) showed that sample sizes for age structures
can be determined for proportional (the number of fish aged is selected proportional to the length frequencies) and
fixed (a constant number are aged per length class) allocation assuming a two-stage random sampling design.
Sample sizes are determined based on the length frequency sample size, a specified
coefficient of variation, and proportional or fixed allocation. The number of age classes is calculated internally.
See reference to Table 8.6, p. 312 in Quinn and Deriso.
References
Quinn, T. J. and R. B. Deriso. 1999. Quantitative Fish Dynamics. Oxford University Press, New York, New York. 542 pages