I have two plots. One with smoothed lines:
library(splines)
library(ggplot2)
ggplot(mtcars, aes(hp, qsec)) + stat_smooth(aes(group = cyl,
colour = factor(cyl)),
method = "glm",
formula = y ~ ns(x, 1),
level = 1e-9,
size = I(1)) +
theme(panel.background=element_rect(fill="transparent",colour=NA),
plot.background=element_rect(fill="transparent",colour=NA),
legend.key = element_rect(fill = "transparent", colour = "transparent"))
and one without:
ggplot(mtcars, aes(hp, qsec)) +
geom_point(aes(group = cyl, colour = factor(cyl))) +
theme(panel.background=element_rect(fill="transparent",colour=NA),
plot.background=element_rect(fill="transparent",colour=NA),
legend.key = element_rect(fill = "transparent", colour = "transparent"))
How can I get a white or transparent legend background in the first plot? And why do the same theme-commands do the job in the second plot?
1 Answer
It seems like the grey background is coming from stat_smooth(), as explained here. Adding se=FALSE, which deactivates the confidence intervals, seems to fix it:
ggplot(mtcars, aes(hp, qsec)) + stat_smooth(aes(group = cyl,
colour = factor(cyl)),
method = "glm",
formula = y ~ ns(x, 1),
level = 1e-9,
size = I(1),
se = FALSE) +
theme(panel.background=element_rect(fill="transparent",colour=NA),
plot.background=element_rect(fill="transparent",colour=NA),
legend.key = element_rect(fill = "transparent", colour = "transparent"))
