### 1 2 3 4 5 6 7 time = c(-353.0, -276, -191, -159, -154, -70, 0, 0, 0, 0, 0, 0) timeR = time+353 pair_No = c( 7019, 1040, 868, 839, 786, 610, 630, 505, 563, 577, 476, 551) NN <- pair_No[1] plot(time, pair_No, xaxp = c(-450, 0, 9), xlim=c(-450,0), pch=20, ylim=c(0,9000)) par(new=T) small_f <- function (a,x) { return( exp(-a*x) ) } F_Tp <- function(a) { return(NN * small_f(a,timeR[7])) } F_Te <- function(a) { return(NN * small_f(a,timeR[6])) } F_Td <- function(a) { return(NN * small_f(a,timeR[5])) } F_Tc <- function(a) { return(NN * small_f(a,timeR[4])) } F_Tb <- function(a) { return(NN * small_f(a,timeR[3])) } F_Ta <- function(a) { return(NN * small_f(a,timeR[2])) } Est <- function(a) {return(c(NN, F_Ta(a), F_Tb(a), F_Tc(a), F_Td(a), F_Te(a), F_Tp(a), F_Tp(a), F_Tp(a), F_Tp(a), F_Tp(a), F_Tp(a)))} resid <-function(pm) { return( sum((Est(pm[1])-pair_No)^2) ) } o <- optimize(resid, c(0.00001, 0.02), tol=0.0001) aa <- o$minimum ## Plotting curve( NN*small_f(aa, T-time[1]), time[1], 0, xname="T", type="l", col="red", add=TRUE )