R/generate_fctcall.R

In DSAIDE: Dynamical Systems Approach to Infectious Disease Epidemiology

#' @title A helper function that produces a call to a simulator function for specific settings
#'
#' @description This function takes a modelsettings structure and uses that information
#' to create an unevaluated function call that runs the simulator function with the specified settings
#' 
#'
#' @param modelsettings a list with model settings. Required list elements are: \cr
#' List elements with names and values for all inputs expected by simulation function. \cr
#' modelsettings$simfunction - name of simulation function in variable  \cr
#' @return A string containing an unevaluated function call with the specified settings
#' @details This function produces a function call for specific settings.
#' @export

generate_fctcall <- function(modelsettings)
{
    #extract modeslettings inputs needed for simulator function
    currentmodel = modelsettings$currentmodel
    #match values provided from UI with those expected by function
    settingsvec = unlist(modelsettings)
    currentargs = settingsvec[match(names(unlist(formals(currentmodel))), names(settingsvec))]
    #get rid of NA that might happen because inputs are not supplied for certain function inputs.
    #in that case we use the function defaults
    currentargs <- currentargs[!is.na(currentargs)]
    #make a list, makes conversion to numeric easier
    arglist = as.list(currentargs)
    #convert arguments for function call to numeric if possible
    #preserve those that can't be converted
    numind = suppressWarnings(!is.na(as.numeric(arglist))) #find numeric values
    arglist[numind] = as.numeric(currentargs[numind])
    #add function name as first element to list
    fctlist = append(parse(text = currentmodel), arglist)
    #make fct call
    fctcall <- as.call(fctlist) 
    return(fctcall)
}