在ggplot中添加多个线性回归线时出错

Question

I try to add my (multiple) linear regression lines on my ggplot. I have two dummies (morning-evening) for the morning.dummy. The plot is correct but it gives me an error when I want to add the regression lines. Here is the code:

regression_1 <- lm(weight  ~ morning.dummy + dayNumber + (morning.dummy*dayNumber) + 
                     I(dayNumber^2) + (I(dayNumber^2)*morning.dummy),
                   data=weight_data)
summary(regression_1)
#plot
plot2 <- ggplot(data=weight_data,aes(x=dayNumber, y=weight, color=morning.dummy)) +
          geom_point()+
          stat_smooth(method = "lm", formula = weight  ~ morning.dummy + dayNumber + (morning.dummy*dayNumber) +I(dayNumber^2) + (I(dayNumber^2)*morning.dummy), size = 1) +
          labs(y = "Weight in kg", x = "Day Number of weight measurment", subtitle = "Day 0 = 3 October 2010")
plot2

This is the error:

Error in grid.Call.graphics(C_setviewport, vp, TRUE) : 
  non-finite location and/or size for viewport
In addition: Warning message:
Computation failed in `stat_smooth()`:
object 'dayNumber' not found 

Does someone have an idea where I do something wrong?

Answer 1

I hope this still help you:

library('ggplot2')

# create test data
weight <- runif(40) * 10
morning <- weight * runif(length(weight))
weight_data <- data.frame(weight, morning)

# test data
ression_1 <- lm( weight ~ poly(morning, degree = 2))
plot(morning, weight)
points(x=morning, y=regression_1$fitted.values, col='red')

#plot in ggplot2
plot2 <- ggplot(data=weight_data, aes(y=weight, x=morning))+
  geom_point()+
  stat_smooth(method = "lm", formula = y ~ poly(x, degree = 2), size = 1)+
  labs(y = "Weight in kg", x = "Day Number of weight measurment", subtitle = "Day 0 = 3 October 2010")

plot2