set.seed(3)

data1 = iris[sample(c(1:dim(iris)[1]), 30), ]
data2 = iris[sample(c(1:dim(iris)[1]), 50), ]

model1 = lm(Petal.Length ~ log(Petal.Width),
            data = data1)
model2 = lm(data2$Petal.Length ~ log(data2$Petal.Width))

par(mfrow = c(1, 4))
plot(data1$Petal.Width,
     data1$Petal.Length)
points(sort(data1$Petal.Width),
       predict(model1, newdata = data1[order(data1$Petal.Width), ]),
       col = "red",
       type = "l")

plot(data2$Petal.Width,
     data2$Petal.Length)
points(sort(data2$Petal.Width),
       predict(model1, newdata = data2[order(data2$Petal.Width), ]),
       col = "red",
       type = "l")


summary(model1)
summary(model2)