nr
is a vector with the expected sample sizes (numbers of individuals and recaptures), usually the output from Enrm
.
unitcost
should be a list with at least one of the components `perkm', `perarray', `perdetector', `pervisit' and `perdetection'.
The number of occasions (noccasions) is incremented by 1 if setupoccasion
is TRUE.
Component | Unit cost | Costing | Arrays |
perarray | perarray x nrepeats | Detectors | perdetector |
perdetector x nrow(traps) x nrepeats | Travel | perkm | perkm x routelength x noccasions x nrepeats |
Visits | pervisit | sum(pervisit x trapcost) x noccasions x nrepeats | Detections |
`Travel' and `Visits' are alternative ways to cost field time. The variable `routelength' represents the length of a path followed to visit all detectors; if not specified it is approximated by the sum of the nearest-trap distances. The variable `trapcost' is a vector of length equal to the number of detectors. By default it is a vector of 1's, but detector- specific values may be provided as trap covariate `costpervisit'. In the latter case the value of `pervisit' should probably be 1.0.
`Arrays' and `Detectors` represent one-off costs.
`Detections' includes costs such as handling time and laboratory DNA analysis.
See ../doc/secrdesign-tools.pdf for more.