似乎应该问这个问题一堆,但我正在搜索Questions that may already have your answer
没有成功。在特定条目上设置R矩阵的子列
你如何用布尔运算符子集(不使用subset()
)矩阵的列?
> m = matrix(c("A", "B", "B", "B", "C", "A", "C", "C", "D"), nrow = 3)
> m
[,1] [,2] [,3]
[1,] "A" "B" "C"
[2,] "B" "C" "C"
[3,] "B" "A" "D"
注意,列没有名字,我想包含在某些条目中的值“d”任何列。
例如,在this post,呼叫grades[grades[,"pass"] == 2,]
。除了调用提取行的事实以及pass
引用单个列的事实之外,列没有名称。
我曾尝试:
> m[m == "D", ]
Error in m[m == "D", ] : (subscript) logical subscript too long
> m[which(m=="D"), ]
Error in m[which(m == "D"), ] : subscript out of bounds
> m = as.data.frame(m) # Turning the matrix into a df
> m[m == "D", ]
V1 V2 V3
NA <NA> <NA> <NA>
真高雅!谢谢! – Toni