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Diffstat (limited to 'R/set_nd.R')
-rw-r--r-- | R/set_nd.R | 118 |
1 files changed, 0 insertions, 118 deletions
diff --git a/R/set_nd.R b/R/set_nd.R deleted file mode 100644 index a9f3df4..0000000 --- a/R/set_nd.R +++ /dev/null @@ -1,118 +0,0 @@ -#' Set non-detects in residue series without replicates -#' -#' Sets non-detects directly before or directly after detects to NA. Values between -#' lod and loq are set to their mean value if an loq is specified. -#' If 'time_zero' is set to TRUE, the residue series is assumed to start with time -#' zero, and non-detects at time zero are set to 'time_zero_nd_value'. For the -#' set_nd_focus variant, this is zero, otherwise this argument has NA as default -#' value. -#' If stopping after the first non-detection is requested, as in in the FOCUS -#' variant of the function, an loq has to be specified in order to decide -#' if any later detections are above the loq. -#' -#' @param r A character vector of sequential residues without replicates, with -#' non-detects specified as 'nd' and unquantified values above the limit of -#' detection specified as 'nq', otherwise coercible to numeric -#' @param lod Limit of detection (numeric) -#' @param loq Limit of quantification(numeric). Must be specified if the FOCUS rule to -#' stop after the first non-detection is to be applied -#' @param time_zero Is the first value in the series a time zero value? -#' @param time_zero_nd_value Which value should we use for non-detects at time zero? -#' @param stop_after_first_nondetect Should we really stop after the first non-detection? -#' @references FOCUS (2014) Generic Guidance for Estimating Persistence and Degradation -#' Kinetics from Environmental Fate Studies on Pesticides in EU Registration, Version 1.1, -#' 18 December 2014, p. 251 -#' @describeIn set_nd Set non-detects in residues series -#' @export -#' @examples -#' # FOCUS (2014) p. 75/76 and 131/132 -#' parent_1 <- c(.12, .09, .05, .03, "nd", "nd", "nd", "nd", "nd", "nd") -#' set_nd(parent_1, 0.02) -#' parent_2 <- c(.12, .09, .05, .03, "nd", "nd", .03, "nd", "nd", "nd") -#' set_nd(parent_2, 0.02) -#' set_nd_focus(parent_2, 0.02, loq = 0.05) -#' parent_3 <- c(.12, .09, .05, .03, "nd", "nd", .06, "nd", "nd", "nd") -#' set_nd(parent_3, 0.02) -#' set_nd_focus(parent_3, 0.02, loq = 0.05) -#' metabolite <- c("nd", "nd", "nd", 0.03, 0.06, 0.10, 0.11, 0.10, 0.09, 0.05, 0.03, "nd", "nd") -#' set_nd(metabolite, 0.02) -set_nd <- function(r, lod, loq = NA, - time_zero = TRUE, time_zero_nd_value = NA, stop_after_first_nondetect = FALSE) -{ - - if (stop_after_first_nondetect & is.na(loq)) { - stop("You need to specify an loq to decide if the curve should be cut off after the first non-detect") - } - - result <- r - - # Handle nq values - if (!missing(loq)) { - nq = 0.5 * (lod + loq) - result[r == "nq"] <- nq - } else { - if (any(r == "nq", na.rm = TRUE)) stop("You need to specify lod and loq") - } - - # Handle nd values - if (time_zero) { - if (r[1] %in% c("nd")) { - residues_present = FALSE - result[1] <- time_zero_nd_value - } else { - residues_present = TRUE - } - start_i <- 2 - } else { - residues_present <- if (r[1] == "nd") FALSE else TRUE - start_i <- 1 - } - - for (i in start_i:length(r)) { - - # residues_in_next - if (i < length(r)) { - next_value <- r[i + 1] - if (is.na(next_value) || next_value == "nd") residues_in_next = FALSE - else residues_in_next = TRUE - } else { - residues_in_next = FALSE - } - - if (is.na(r[i])) { - residues_present <- FALSE - result[i] <- NA - } else { - if (r[i] == "nd") { - if (residues_present | residues_in_next) { - result[i] <- 0.5 * lod - } else { - result[i] <- NA - } - - if (stop_after_first_nondetect) { - if (residues_present & !residues_in_next) { - remaining <- (i + 1):length(r) - if (!any(suppressWarnings(as.numeric(r[remaining])) > loq, na.rm = TRUE)) { - result[remaining] <- NA - return(as.numeric(result)) - } - } - } - if (!residues_in_next) residues_present <- FALSE - else residues_present <- TRUE - } else { - residues_present <- TRUE - } - } - } - return(as.numeric(result)) -} - -#' @describeIn set_nd Set non-detects in residues series according to FOCUS rules -#' @export -set_nd_focus <- function(r, lod, loq = NA, time_zero = TRUE) { - result <- set_nd(r, lod, loq = loq, time_zero = time_zero, - time_zero_nd_value = 0, stop_after_first_nondetect = TRUE) - return(result) -} |