似乎應該問這個問題一堆,但我正在搜索Questions that may already have your answer
沒有成功。在特定條目上設置R矩陣的子列
你如何用布爾運算符子集(不使用subset()
)矩陣的列?
> 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,列沒有名字,我想包含在某些條目中的值「d」任何列。
例如,在this post,呼叫grades[grades[,"pass"] == 2,]
。除了調用提取行的事實以及pass
引用單個列的事實之外,列沒有名稱。
我曾嘗試:
> 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!謝謝! – Toni