generate.sample.lt: Line Transect Method Survey Data Generation

Description Usage Arguments Details Value See Also Examples

Description

This function uses the data stored in the 'pars.survey.lt´ object to create a line transect sample object.

Usage

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        generate.sample.lt(pars.survey.lt, seed = NULL)

Arguments

pars.survey.lt

object returned by the function setpars.survey.lt defining the survey parameters.

seed

number passed to set.seed() to initialise random number generator

Details

A line transect method sample object is generated by simulating a line transect survey of the population specified in generate.sample.lt. The function setpars.survey.lt must have been run to create a ‘pars.survey.lt’ object, which contains the survey specifations.

Value

generate.sample.lt returns an object of class 'sample.lt´ which has the following elements:

population

object of class 'population´.

design

object of class 'design.lt´.

detected

vector indicating which animal groups have been detected. NA means that an animal group was outside all survey units and could not be detected. 0 indicates that an animal group was inside a survey unit however has not been detected. 1 means that an animal group was inside a survey unit and has been detected.

distance

vector of perpendicular distances of animal groups inside the survey units from the respective transect paths.

transect

vector of transect path numbers of detectable animal groups.

parents

Details of WiSP objects passed to function

created

Creation date and time

seed

Equal to the argument 'seed' passed to the function

See Also

setpars.survey.lt, summary.sample.lt plot.sample.lt

Examples

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lt.reg <- generate.region(x.length = 100, y.width = 50)
lt.dens <- generate.density(lt.reg)

#heterogeneous population
lt.poppars<-setpars.population(density.pop = lt.dens, number.groups = 1000,
                              size.method = "poisson", size.min = 1, size.max = 30,
                              size.mean = 10, exposure.method = "beta", exposure.min = 0,
                              exposure.max = 1, exposure.mean = 0.4, exposure.shape = 0.5,
                              type.values=c("Male","Female"), type.prob=c(0.48,0.52))
lt.pop<-generate.population(lt.poppars)
lt.despars<-setpars.design.lt(lt.reg, n.transects=10, n.units=10, visual.range=4, percent.on.effort=1)
lt.des<-generate.design.lt(lt.despars, seed=3)
lt.survpars<-setpars.survey.lt(lt.pop, lt.des, disthalf.min=2, disthalf.max=4)

lt.samp<-generate.sample.lt(lt.survpars)
summary(lt.samp)
plot(lt.samp)

dill/wisp documentation built on May 15, 2019, 8:31 a.m.