Systematic_variance_1 {Distance}R Documentation

Simulation of encounter rate variance

Description

systematic_var_1 consists of simulated line transect data with large differences in transect length. In systematic_var_2 that transect length gradient is coupled with a strong animal gradient; exaggerating encounter rate variance between transects.

Format

data.frame with 253 observations (systematic_var_1) or 256 observations (systematic_var_2) of 7 variables: Region.Label stratum label (default) Area stratum area (0.5 km^2) Sample.Label transect identifier Effort transect length (km) object object ID distance perpendicular distance (m) Study.Area name of study area

Details

True population size is 1000 objects in the study area of size 0.5 km^2; such that true density is 2000 objects per km.

References

Fewster, R.M., S.T. Buckland, K.P. Burnham, D.L. Borchers, P.E. Jupp, J.L. Laake and L. Thomas. (2009) Estimating the encounter rate variance in distance sampling. Biometrics 65 (1): 225–236. doi: 10.1111/j.1541-0420.2008.01018.x


[Package Distance version 1.0.3 Index]