Extract matrix column values by matrix column name

RMatrixSubset

R Problem Overview

Is it possible to get a matrix column by name from a matrix?

I tried various approaches such as myMatrix["test", ] but nothing seems to work.

R Solutions

Solution 1 - R

Yes. But place your "test" after the comma if you want the column...

> A <- matrix(sample(1:12,12,T),ncol=4)

> rownames(A) <- letters[1:3]

> colnames(A) <- letters[11:14]
> A[,"l"]
 a  b  c 
 6 10  1

see also help(Extract)

Solution 2 - R

> myMatrix <- matrix(1:10, nrow=2)
> rownames(myMatrix) <- c("A", "B")
> colnames(myMatrix) <- c("A", "B", "C", "D", "E")

> myMatrix
  A B C D  E
A 1 3 5 7  9
B 2 4 6 8 10

> myMatrix["A", "A"]
[1] 1

> myMatrix["A", ]
A B C D E 
1 3 5 7 9 

> myMatrix[, "A"]
A B 
1 2
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Content TypeOriginal AuthorOriginal Content on Stackoverflow
QuestionSurajView Question on Stackoverflow
Solution 1 - RJoris MeysView Answer on Stackoverflow
Solution 2 - RboraasView Answer on Stackoverflow