所有参赛：
"p" for points,
"l" for lines,
"b" for both,
"c" for the lines part alone of "b",
"o" for both ‘overplotted’,
"h" for ‘histogram’ like (or ‘high-density’) vertical lines,
"s" for stair steps,
"S" for other steps, see ‘Details’ below,
"n" for no plotting.
利用spline函数比如
x<-rnorm(50,0,3) #利用正态分布产生50个随机数
sp<-spline(x) #进行平滑处理
plot(sp,type="l") #画出图像
