segmented_reg

library(segmented)
library(tidyverse)

#view DataFrame
df <- data.frame(x=c(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16),
                 y=c(2, 4, 5, 6, 8, 10, 12, 13, 15, 19, 24, 28, 31, 34, 39, 44))

df2 <- data.frame(x=c(2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)+2,
                 y=c(4, 5, 6, 8, 10, 12, 13, 15, 19, 24, 28, 31, 34, 39))

fit <- lm(y ~ x, data=df)
segmented.fit <- segmented(fit, seg.Z = ~x, psi=9)
preds1 <- data.frame(x = seq(min(df$x), max(df$x)), 
                     y = fitted(segmented.fit))

fit2 <- lm(y ~ x, data=df2)
segmented.fit2 <- segmented(fit2, seg.Z = ~x, psi=9)
preds2 <- data.frame(x = seq(min(df2$x), max(df2$x)), 
                     y = fitted(segmented.fit2))
preds1 %>% 
ggplot() +
  geom_line(aes(x,y, col="hib A"))+ 
  geom_point(aes(x,y), col="red")+
  geom_line(data = preds2, aes(x,y, col="hib B"), )+
  geom_point(data = preds2, aes(x,y), col="green") +
  scale_colour_manual("Hibrido", values = c("red", "green"))