create.scen.factors: create.scen.factors

In HumanExposure/SHEDSDevel: The SHEDS-HT model for estimating human exposure to chemicals.

Description

This function takes the information on distributions from the all.scenarios data set (which comes from the source_variables_12112015 input file) and converts it into the parameter set needed by SHEDS.HT.

Usage

create.scen.factors(f)

Arguments

f	An internally generated data set from the Source_vars input file (as specified in the Run file) containing data on the distribution of each source variable in SHEDS.HT.

Details

The steps involved in this function are 1) converting prevalence from a percentage to a binomial form, 2) converting CV to standard deviation for normals, and 3) converting Mean and CV to par1 and par2 for lognormals. Note that prevalence in SHEDS becomes a binomial distribution, which returns a value of either 0 or 1 when evaluated. Each simulated person either "does" or "does not" partake in this scenario. Similar logic applies to the frequency variable, except that the returned values may be larger than one (that is, 2 or more) for very frequent scenarios. All the exposure equations contain the prevalence variable. If prevalence is set to one for that person, the exposure is as expected, but if prevalence=0 then no exposure occurs.

Value

dt A data set with values and probabilities associated with each variable distribution presented in f. All variables in f are also retained.

Author(s)

Kristin Isaacs, Graham Glen

See Also

Source_vars, Run

HumanExposure/SHEDSDevel documentation built on Oct. 30, 2019, 6:49 p.m.