rc()创建一个容器,该容器与连接的对象具有相同的类。对的?

数值向量是R中的原子对象,而不是容器,下面的3个对象都是具有类的数值向量 "numeric" 最后两个是一样的。

0.5 和 0.6 放入容器 c(0.5, 0.6) 0.5 用向量 0.6 .

# these are all numeric vectors
c(0.5,0.6)
c(0.5)
9.5

# the last two objects above are identical
identical(c(0.5), 0.5)
## [1] TRUE

# they are all of class "numeric"
class(c(0.5, 0.6))
## [1] "numeric"
class(0.5)
## [1] "numeric"

列表是复杂的对象,可以看作容器,但不能看作数字向量。

# numeric vectors, but not lists, are atomic
is.atomic(c(0.5, 0.6))
## [1] TRUE
is.atomic(list(0.5, 0.6))
## [1] FALSE

我不确定我能完全回答,但注意到R中没有标量,只有长度为1的向量可能会有所帮助。当你使用 c()

x <- 0
typeof(x)
#[1] "double"
length(x)
#[1] 1         # Now we have a double vector of length one.

y <- c(0)
typeof(y)
#[1] "double"
length(y)
#[1] 1         # Using c(), we made another double vector also of length one.

identical(x, y)  # are x and y identical objects?
#[1] TRUE        #  yep!

z <- c(0, 0)   # Now, use c() with two values
typeof(z)
#[1] "double"
length(z)
#[1] 2          # now we have a double vector of length two.

identical(x, z)
[1] FALSE