I'm using the effects package to plot interaction effects of a linear regression like this:
library(effects)
Model <- lm(drat~hp*cyl, data=mtcars)
plot(effect(term="hp*cyl",mod=Model,default.levels=10),multiline=TRUE)
How do I change the limits so that they go from say 0-10? I've tried with ylim=(0,10), and other variations with no effect. Alternatively, can a regression be plotted in the same way using ggplot2?
And here is the ggplot2 version:
library(effects)
library(ggplot2)
Model <- lm(drat~hp*cyl, data=mtcars)
ef <- effect(term = "hp:cyl", Model, default.levels = 9) # 9 because the breaks are nicer
ef2 <- as.data.frame(ef)
ggplot(ef2, aes(hp, fit, col = factor(cyl))) +
geom_line() +
labs(y = 'drat') +
ylim(0, 10)
With the plot function, set ylim like this
plot(effect(term="hp*cyl",mod=Model,default.levels=10),multiline=TRUE,ylim=c(0,10))
ggplot2 doesn't know how to deal with an data of class 'eff', so you need to convert your effects data into a dataframe before plotting. You can then use group= with your data inside aes() to get lines for each group.
library(effects)
library(ggplot2)
Model <- lm(drat~hp*cyl, data=mtcars)
e<-effect(term="hp*cyl",mod=Model,default.levels=10)
ee<-data.frame(e)
ee$cyl<-factor(ee$cyl)
ggplot(ee, aes(x = hp, y = fit, group = cyl, colour = cyl)) +
geom_line() +
scale_y_continuous(limits = c(0,10))
