获取列名称，该列名称在矩阵的行内保存最大值，该矩阵在数组中保持单独的最大值 [英] Getting column name which holds a max value within a row of a matrix holding a separate max value within an array

问题描述

例如给出：

dim1 <- c("P","PO","C","T")
dim2 <- c("LL","RR","R","Y")
dim3 <- c("Jerry1", "Jerry2", "Jerry3")
Q <- array(1:48, c(4, 4, 3), dimnames = list(dim1, dim2, dim3))

我想在这个数组中引用，在（第3行，第4列）位置具有max dim3值的矩阵。

I want to reference within this array, the matrix that has the max dim3 value at the (3rd row, 4th column) location.

识别出矩阵后，我想将矩阵（第3行，第1列）中具有最大值的列名返回到（第3行，第3列）范围。

Upon identifying that matrix, I want to return the column name which has the maximum value within the matrix's (3rd Row, 1st Column) to (3rd Row, 3rd Column) range.

所以我希望发生的是Jerry3被引用，因为数字47存储在第3行，第4列，然后在Jerry3中，我希望第3行中的最大数量为得到引用的是43，最终，我需要返回的（我需要的唯一值）就是列名称R。

So what I'd hope to happen is that Jerry3 gets referenced because the number 47 is stored in its 3rd row, 4th column, and then within Jerry3, I would want the maximum number in row 3 to get referenced which would be 43, and ultimately, what I need returned (the only value I need) is then the column name which would be "R".

这就是什么我需要知道怎么做，获得那个R和将它分配给一个变量，即column_ref，这样column_ref< - R。

That's what I need to know how to do, obtain get that "R" and assign it to a variable, i.e. "column_ref", such that column_ref <- "R".

请请帮助。

推荐答案

这应该这样做 - 如果我理解正确的话：

This should do it - if I understand correctly:

Q <- array(1:48, c(4,4,3), dimnames=list(
  c("P","PO","C","T"), c("LL","RR","R","Y"), c("Jerry1", "Jerry2", "Jerry3")))

column_ref <- names(which.max(Q[3,1:3, which.max(Q[3,4,])]))[1] # "R"

一些解释：

which.max(Q[3,4,]) # return the index of the "Jerry3" slice (3)
which.max(Q[3,1:3, 3]) # returns the index of the "R" column (3)

...然后 names 返回索引的名称（R） 。

...and then names returns the name of the index ("R").

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