#Channa, snakehead fish
age<-c(6.9562583, 6.952816, 7.942101, 5.8946915, 7.8840175, 10.897048, 13.833063, 14.892336, 14.84802, 16.871336,  17.93663, 20.811264, 22.930668, 24.862772, 25.828535)
length<-c(12.778474, 13.53796, 14.115646, 28.150002, 26.931978, 18.69678, 27.455086,  28.22322, 38.001606, 29.283657, 28.72269, 35.391834, 36.73823, 48.14667, 38.28084)
plot(age,length,xlim=c(0,25),ylim=c(0,50), ylab= "Length (cm)", xlab= "Age (months)")

modelG<-nls(length ~ C*(1-exp(-a*age)), start=c(C=100, a=0.5))
summary (modelG)

xv<-seq(0,25,0.1) # this generates a sequence from 0 to 25 in increments of 0.1, it is shorthand for seq(from=0, to=25, by=0.1)
yv<-predict(modelG, list(age=xv))

lines(xv, yv, lwd=2, col= "blue")