> for(m in 1:seq(1,10,2)) print("Hello")
[1] "Hello"
Warning message:
In 1:seq(1, 10, 2) :
  numerical expression has 5 elements: only the first used
> for(m in 1:seq(1,10,2)) print(m)
[1] 1
Warning message:
In 1:seq(1, 10, 2) :
  numerical expression has 5 elements: only the first used
明明有5次循环，为什么每次就执行第一次循环的结果？