logObsInd: The actual observation index function

Description Usage Arguments Value References

View source: R/observationIndex.R

Description

This function implements the algorithms to calculate the observation index. OI = log ( (At / (At + Rt) ) / ( A / (A + R) ) ) where At is the sum of observations for focal species during time t (or grid), Rt is sum of observations of all species in reference group during t, A and R are the total sums for observations.

Usage

1
logObsInd(focal, group, fs.rm = TRUE, norm = TRUE)

Arguments

focal

observations/visits for the focal species

group

observations/visits for the reference species group

fs.rm

if TRUE, assumes that the observations for the focal species are included in 'group' and will remove them

norm

if TRUE, the result is normalized to a 0-1 range

Value

a positive observation index

References

Telfer, Preston & Rothery (2002) <doi:10.1016/S0006-3207(02)00050-2>


BIRDS documentation built on June 27, 2021, 1:06 a.m.