GenEst (version 1.4.9)

estg: Estimate all carcass-level detection rates and arrival intervals

Description

Estimate g values and arrival intervals for a set of carcasses from fitted pk and cp models and search data

Usage

estg(
  data_CO,
  COdate,
  data_SS,
  SSdate = NULL,
  model_SE,
  model_CP,
  model_DWP = NULL,
  sizeCol = NULL,
  unitCol = NULL,
  IDcol = NULL,
  nsim = 1000,
  max_intervals = 8
)

Value

list of [1] g estimates (ghat) and [2] arrival interval estimates (Aj) for each of the carcasses. The row names of the

Aj matrix are the units at which carcasses were found. Row names of

ghat are the carcass IDs (in data_CO).

Arguments

data_CO

Carcass Observation data

COdate

Column name for the date found data

data_SS

Search Schedule data

SSdate

Column name for the date searched data. Optional. If not provided, estg will try to find the SSdate among the columns in data_SS. See prepSS.

model_SE

Searcher Efficiency model (or list of models if there are multiple carcass classes)

model_CP

Carcass Persistence model (or list of models if there are multiple carcass classes)

model_DWP

Density weighted proportion model (or list of models if there are multiple carcass classes)

sizeCol

Name of column in data_CO where the carcass classes are recorded. Optional. If not provided, no distinctions are made among sizes. sizeCol not only identifies what the name of the size segregating class

unitCol

Column name for the unit indicator

IDcol

Column name for unique carcass IDs (required)

nsim

the number of simulation draws

max_intervals

maximum number of arrival interval intervals to consider for each carcass. Optional. Limiting the number of search intervals can greatly increase the speed of calculations with only a slight reduction in accuracy in most cases.

Examples

 data(mock)
 model_SE <- pkm(formula_p = p ~ HabitatType, formula_k = k ~ 1,
              data = mock$SE)
 model_CP <- cpm(formula_l = l ~ Visibility, formula_s = s ~ Visibility, 
               data = mock$CP, dist = "weibull",
               left = "LastPresentDecimalDays", 
               right = "FirstAbsentDecimalDays"
             )
 ghat <- estg(data_CO = mock$CO, COdate = "DateFound",  data_SS = mock$SS,
      model_SE = model_SE, model_CP = model_CP, unitCol = "Unit", nsim = 100)