矢量的密度图显示在最小和最大值之前和之后的尾巴

Question

我有以下向量：

v<-c(1, 1, 8, 3, 1, 9, 4, 21, 13, 13, 1, 1, 3, 10, 1, 13, 22, 1, 
1, 4, 2, 1, 13, 1, 5, 1, 2, 1, 1, 2, 12, 10, 26, 15, 2, 9, 6, 
5, 1, 3, 18, 2, 10, 2, 8, 9, 4, 1, 11, 4, 2, 12, 3, 14, 2, 1, 
27, 3, 6, 2, 1, 1, 3, 16, 3, 36, 13, 9, 11, 10, 24, 2, 27, 4, 
4, 2, 9, 1, 3, 13, 3, 1, 8, 5, 5, 15, 1, 1, 3, 1, 4, 14, 8, 1, 
1, 2, 20, 1, 9, 3, 1, 2, 5, 14, 5, 11, 1, 3, 2, 9, 10, 21, 9, 
1, 20, 5, 11, 23, 2, 1, 1, 2, 1, 7, 2, 9, 1, 19, 9, 9, 2, 15, 
17, 8, 11, 17, 2, 14, 2, 8, 13, 1, 2, 9, 15, 25, 3, 8, 32, 4, 
11, 1, 1, 2)

我想通过命令密度在r中估算其密度。几行代码：

d<-density(v)
df<-data.frame(x=d$x,y=d$y,stringsAsFactors = FALSE)
plot(df)

我获得了以下图片：

​v）是1，而图表在0和40之前和之后显示尾巴。