问题
I have the following simple R code:
disciplines <- c("A","C","B","D","E") # To stop ggplot from imposing alphabetical ordering on x-axis disciplines <- factor(disciplines, levels=disciplines, ordered=T) d1 <- c(0.498, 0.521, 0.332, 0.04, 0.04) d2 <- c(0.266, 0.202, 0.236, 0.06, 0.06) d3 <- c(0.983, 0.755, 0.863, 0.803, 0.913) d4 <- c(0.896, 0.802, 0.960, 0.611, 0.994) df <- data.frame(disciplines, d1, d2, d3, d4) df.m <- melt(df) graph <- ggplot(df.m, aes(group=1,disciplines,value,colour=variable,shape=variable)) + geom_point() + geom_smooth(stat="smooth", method=loess, level=0.95) + scale_x_discrete(name="Disciplines") + scale_y_continuous(limits=c(-1,1), name="Measurement") The output looks like this:
Why does the confidence interval not display along the entire curve?
Notes:
- I don't want to have
fullrange=TRUEbecause that just yields a single straight blue line instead of the zigzag shape in the current output. - I am comparing this plot with another plot which has negative values in the (0,-1] range, which is why the y-axis has
limits=c(-1,1))
回答1:
For the first three segments of the confidence interval, the top end of the range is at least partially out of bounds (the bounds being [-1, 1], not the slightly expanded range on the axes). ggplot's default behavior is to not display any object that is partially out of bounds. You can fix this by adding oob=scales::rescale_none to scale_y_continuous:
library(scales) graph <- ggplot(df.m, aes(group=1,disciplines,value,colour=variable,shape=variable)) + geom_point() + geom_smooth(stat="smooth", method=loess, level=0.95) + scale_x_discrete(name="Disciplines") + scale_y_continuous(limits=c(-1,1), name="Measurement", oob=rescale_none) 回答2:
A better documented, and perhaps more intuitive, solution would be to simply use coord_cartesian:
ggplot(df.m, aes(group=1,disciplines,value,colour=variable,shape=variable)) + geom_point() + geom_smooth(stat="smooth", method=loess, level=0.95) + scale_x_discrete(name="Disciplines") + coord_cartesian(ylim = c(-1,1)) 来源：https://stackoverflow.com/questions/19148702/r-confidence-interval-being-partially-displayed-with-ggplot2-using-geom-smoot