通过row.names子集化矩阵

时间:2014-03-26 18:54:35

标签: r data-manipulation

我有一个矩阵,其中包含以下row.names:

"X1"   "X5"   "X33"  "X37"  "X52"  "X566"

现在我想只选择与列表条目匹配的行,例如:

include_list <- c("X1", "X5", "X33")

我想我会做这样的事情:

data.subset <- subset(data, row.names == include_list)

但是,这个特殊代码似乎没有完成这项工作。如何以这种方式执行子集化?

3 个答案:

答案 0 :(得分:26)

设置一些假数据:

m <- matrix(1:30, 6, 5)
rownames(m) <- c("X1", "X5", "X33", "X37", "X52", "X566")
m
#      [,1] [,2] [,3] [,4] [,5]
# X1      1    7   13   19   25
# X5      2    8   14   20   26
# X33     3    9   15   21   27
# X37     4   10   16   22   28
# X52     5   11   17   23   29
# X566    6   12   18   24   30

这里使用矩阵索引([)进行子集可能最简单:

include_list <- c("X1", "X5", "X33")
m[include_list, ]
#     [,1] [,2] [,3] [,4] [,5]
# X1     1    7   13   19   25
# X5     2    8   14   20   26
# X33    3    9   15   21   27

替代subset()函数:

subset(m, rownames(m) %in% include_list)
#      [,1] [,2] [,3] [,4] [,5]
# X1     1    7   13   19   25
# X5     2    8   14   20   26
# X33    3    9   15   21   27

答案 1 :(得分:3)

这似乎也有效:

include_list <- head(read.csv("/Users/histelheim/include_list.csv", header = FALSE))
include_list <- c(do.call("cbind", include_list)) 
data[row.names(data) %in% include_list, ]

答案 2 :(得分:0)

只要某人的 include_list 是类 list (而不是矢量),那么这是Rich Scriven答案的修改,在这种情况下基于{{3} }。 unlist()应该添加:

m <- matrix(1:30, 6, 5)
rownames(m) <- c("X1", "X5", "X33", "X37", "X52", "X566")
include_list <- list("X1", "X5", "X33")


m[unlist(include_list), ]