cyl== ...

Question

We can use the

operator to subset the data as requested in the OP.

cylChoices = c(4,6)
subset(mtcars,cyl==cylChoices[1] | cyl== cylChoices[2])

...and the first few rows of output:

`%in% can also be used with the extract operator, such as:

cars = list()
cylChoices = c(4,6)
count = 1
for(tempChoice in cylChoices){
count =count+1
cars[[count]] = subset(mtcars,cyl==tempChoice)
}

An option with

Answer 1

我曾经用for循环来实现这个目标，但是这样做的结果是感觉代码太长了，比如说。%in%这样做的结果是不一样的，但已经很接近了。

cylChoices = c(4,6)
subset(mtcars,cyl %in% cylChoices)

有没有什么方法可以轻松地匹配一个子集？

                mpg cyl  disp  hp drat    wt  qsec vs am gear carb
Mazda RX4      21.0   6 160.0 110 3.90 2.620 16.46  0  1    4    4
Mazda RX4 Wag  21.0   6 160.0 110 3.90 2.875 17.02  0  1    4    4
Datsun 710     22.8   4 108.0  93 3.85 2.320 18.61  1  1    4    1
Hornet 4 Drive 21.4   6 258.0 110 3.08 3.215 19.44  1  0    3    1
Valiant        18.1   6 225.0 105 2.76 3.460 20.22  1  0    3    1
Merc 240D      24.4   4 146.7  62 3.69 3.190 20.00  1  0    4    2
Merc 230       22.8   4 140.8  95 3.92 3.150 22.90  1  0    4    2
Merc 280       19.2   6 167.6 123 3.92 3.440 18.30  1  0    4    4
Merc 280C      17.8   6 167.6 123 3.92 3.440 18.90  1  0    4    4

非常感谢您的时间！我正在尝试子集。

mtcars[mtcars$cyl %in% cylChoices,]

Answer 2

我试图从mtcars中进行子集，使行中有一个特定的列，它与存储在列表中的任意一个值相匹配。 cylChoices = c(4,6) subset(mtcars,cyl===cylChoices[1]