R/Cy0.R

In qpcR: Modelling and Analysis of Real-Time PCR Data

Cy0 <- function(object, plot = FALSE, add = FALSE, ...)
{
  cpD1 <- efficiency(object, plot = FALSE)$cpD1 
  Fluo <- as.numeric(predict(object, newdata = data.frame(Cycles = cpD1), which = "y")) 
  slope <- object$MODEL$d1(cpD1, t(coef(object)))
  Cy0 <- cpD1 - (Fluo/slope)
  
  if (plot) {
    plot(object, ...) 
    add = TRUE
  }
  if (add) {
    points(cpD1, Fluo, col = "blueviolet", pch = 16, ...)
    abline((-cpD1 * slope) + Fluo, slope)
    abline(h = 0)
    points(Cy0, 0, col = "blueviolet", pch = 16, ...)
  }
  return(round(Cy0, 2))
}