R没有绘制回归线

Question

So I'm trying to get a regression line to show up on the data plot, and it isn't working. I tried restarting R, checked the code, it looks totally fine to me. The abline() command worked for every other plot I've made today, just not this one.

Here's the commands I used:

hw3c <- read.csv(file.choose(), header = T)
model.3c <- lm(hw3c)
plot(hw3c)
abline(model.3c)

The data is:

Crab,Sal
0.7,3
1.7,3.2
1.3,6.5
2.2,6.5
0.9,9.4
3.2,23.4
5,27.1

I know this is stupidly simple, I don't get why it isn't working. Help?

Answer 1

Your model is Crab ~ Sal while your plot is Sal ~ Crab . Change one or the other. Eg:

abline(lm(Sal ~ Crab, data=hw3c))

gives you a line of best fit.