I would like to make a subset of a data frame in R that is based on one OR another value in a column of factors but it seems I cannot use | with factor values.
我想在R中创建一个数据帧的子集，它基于一列因子中的一个或另一个值，但似乎我不能使用与因子值。
Example:
例：
# fake data
x <- sample(1:100, 9)
nm <- c("a", "a", "a", "b", "b", "b", "c", "c", "c")
fake <- cbind(as.data.frame(nm), as.data.frame(x))
# subset fake to only rows with name equal to a or b
fake.trunk <- fake[fake$nm == "a" | "b", ]
produces the error:
产生错误：
Error in fake$nm == "a" | "b" :
operations are possible only for numeric, logical or complex types
How can I accomplish this?
我怎么能做到这一点？
Obviously my actual data frame has more than 3 values in the factor column so just using != "c" won't work.
显然，我的实际数据框在因子列中有超过3个值，所以只使用！=“c”将不起作用。
2 个解决方案
#1
24
You need fake.trunk <- fake[fake$nm == "a" | fake$nm == "b", ]. A more concise way of writing that (especially with more than two conditions) is:
你需要fake.trunk < - 假[假$ nm ==“a”|假$ nm ==“b”，]。一种更简洁的写作方式（特别是有两个以上的条件）是：
fake[ fake$nm %in% c("a","b"), ]
#2
13
Another approach would be to use subset() and write
另一种方法是使用subset（）和write
fake.trunk = subset(fake, nm %in% c('a', 'b'))
#1
24
You need fake.trunk <- fake[fake$nm == "a" | fake$nm == "b", ]. A more concise way of writing that (especially with more than two conditions) is:
你需要fake.trunk < - 假[假$ nm ==“a”|假$ nm ==“b”，]。一种更简洁的写作方式（特别是有两个以上的条件）是：
fake[ fake$nm %in% c("a","b"), ]
#2
13
Another approach would be to use subset() and write
另一种方法是使用subset（）和write
fake.trunk = subset(fake, nm %in% c('a', 'b'))