R/DRC.const.R

In OnofriAndreaPG/drcSeedGerm: Utilities for data analyses in seed germination/emergence assays

DRC.const <- function(fixed = c(NA), names = c("d"))
{
    ## Checking arguments
    numParm <- 1
    if (!is.character(names) | !(length(names) == numParm)) {stop("Not correct 'names' argument")}
    if (!(length(fixed) == numParm)) {stop("Not correct 'fixed' argument")}

    ## Fixing parameters (using argument 'fixed')
    notFixed <- is.na(fixed)
    parmVec <- rep(0, numParm)
    parmVec[!notFixed] <- fixed[!notFixed]

    ## Defining the non-linear function
    fct <- function(x, parm)
    {
        parmMat <- matrix(parmVec, nrow(parm), numParm, byrow = TRUE)
        parmMat[, notFixed] <- parm

        d <- parmMat[, 1]
        d
    }

    ## Defining self starter function
    ssfct <- function(dataf)
    {
        x <- dataf[, 1]
        y <- dataf[, 2]
        d <- mean(y)
        return(c(d)[notFixed])
    }

    ## Defining names
    pnames <- names[notFixed]

    ## Defining derivatives

    ## Defining the ED function

    ## Defining the inverse function

    ## Defining descriptive text
    text <- "Constant function"

    ## Returning the function with self starter and names
    returnList <- list(fct = fct, ssfct = ssfct, names = pnames, text = text, noParm = sum(is.na(fixed)))

    class(returnList) <- "drcMean"
    invisible(returnList)
}