Description Usage Arguments Value Methods (by class) Values Note References Examples
PetersenEst
calculates abundance estimates using
mark-recapture data. Function is designed following equations detailed in
Ricker 1975 (see References). Currently, we use Bailey's modified
equation (see eqn 3.9, page 79 in Ricker 1975).
1 2 3 4 5 6 7 | PetersenEst(x, ...)
## S3 method for class 'numeric'
PetersenEst(x, CC, RR, ..., alpha = 0.05)
## S3 method for class 'PetersenEst'
print(x, ...)
|
x |
Numeric. Number of fish marked (tagged). |
... |
Currently not used. |
CC |
Numeric. Number of fish caught or sampled. |
RR |
Numeric. Number of recaptured fish (tags) in the sample. |
alpha |
Numeric scalar used to calculated |
A list (of class PetersenEst
) containing items in
Values
section.
numeric
: for object class 'numeric'.
PetersenEst
: print
method (See notes).
absolute abundance estimate
.
variance of N
.
confidence interval as SE * Z
.
standard error as sqrt(Var)
.
CI level as a result of Z; e.g., 95%
.
given as qnorm(1 - alpha / 2)
,
where alpha = 0.05 for 95% CI
.
Method print
written for class PetersenEst returns estimate
with confidence interval.
Ricker, W.E. (1975). Computation and interpretation of biological statistics of fish populations. Bulletin of the Fisheries Research Board of Canada, Bulletin 191, Ottawa. http://www.dfo-mpo.gc.ca/Library/1485.pdf
1 | # coming soon
|
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