Novice vs Competent
Given the matrix M:
[,1] [,2] [1,] 6 3 [2,] 5 2 [3,] 4 1
What is the output of dim(M[1,])?
(a) NULL
(b) 3 2
(c) 1 2
(d) 3 1
Competent vs Expert
Given the matrix M:
[,1] [,2] [1,] 6 3 [2,] 5 2 [3,] 4 1
What index returns rows 2 and 3?
(a) c(2,3)
(b) c(-1)
(c) c(1,3)
(d) c(2:3)