R/CtIndividualPoint.R

In dpwynne/mmnst: Multiscale Modeling of Neural Spike Trains

#' \eqn{c(t)} at Individual Points
#'
#' Computes the estimated piecewise constant intensity function c(t) at a particular time point t1.
#'
#' @param t1 a single time value.
#' @param terminal.points a numeric vector containing the time points at which c(t) changes.
#' @param ct a numeric vector containing the estimated piecewise constant intensity function c(t).
#'
#' @return A single numeric value of c(t).
#'
#' @export

CtIndividualPoint<-function(t1, terminal.points, ct){
	##if t1 is outside the time frame specified by t.start and t.end, c(t1) is 0
	if( t1 < min(terminal.points) | t1 > max(terminal.points) ) return(0)
	##if t1 is t.start or t.end, c(t1) is the appropriate value
	if (t1 == min(terminal.points)) return( ct[1] )
	if (t1 == max(terminal.points)) return( ct[length(ct)] )
	##otherwise find the terminal point immediately before t1
	ct.indx <- max(which(terminal.points <= t1))
	return(ct[ct.indx])
}