我有以下代码,包括随机生成的演示数据:
n <- 10
group <- rep(1:4, n)
mass.means <- c(10, 20, 15, 30)
mass.sigma <- 4
score.means <- c(5, 5, 7, 4)
score.sigma <- 3
mass <- as.vector(model.matrix(~0+factor(group)) %*% mass.means) +
rnorm(n*4, 0, mass.sigma)
score <- as.vector(model.matrix(~0+factor(group)) %*% score.means) +
rnorm(n*4, 0, score.sigma)
data <- data.frame(id = 1:(n*4), group, mass, score)
head(data)
这使:
id group mass score
1 1 1 12.643603 5.015746
2 2 2 21.458750 5.590619
3 3 3 15.757938 8.777318
4 4 4 32.658551 6.365853
5 5 1 6.636169 5.885747
6 6 2 13.467437 6.390785
然后我想在条形图中绘制按“组”分组的“分数”的总和:
plot <- ggplot(data = data, aes(x = group, y = score)) +
geom_bar(stat="sum")
plot
This gives me:
奇怪的是,使用stat_identity
似乎给出了我正在寻找的结果:
plot <- ggplot(data = data, aes(x = group, y = score)) +
geom_bar(stat="identity")
plot
这是一个错误吗?在 R 上使用 ggplot2 1.0.0
platform x86_64-pc-linux-gnu
arch x86_64
os linux-gnu
system x86_64, linux-gnu
status
major 3
minor 1.2
year 2014
month 10
day 31
svn rev 66913
language R
version.string R version 3.1.2 (2014-10-31)
nickname Pumpkin Helmet
或者我做错了什么?