Explanation:solve(A,B) implies inverse of A * B. 7. Which of the following finds row sums for each level of a grouping variable ?
A. as.numeric(x)
B. rowsum(x, group, reorder = TRUE, …)
C. as.order(x)
D. colSums (x, na.rm = FALSE, dims = 1)
Answer:A
Explanation:solve(A,B) implies inverse of A * B. 7. Which of the following finds row sums for each level of a grouping variable ?
A. as.numeric(x) B. rowsum(x, group, reorder = TRUE, …) C. as.order(x) D. colSums (x, na.rm = FALSE, dims = 1)
Explanation:rowsum compute column sums across rows of a numeric matrix-like object for each level of a grouping variable. 8. Which of the following sets the size of the outer margins for the graph ?