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)The question was posed to me in examination.This is a very interesting question from Commands in portion Commands, Packages, Visualizing Data and Linear Regression of R Programming

Which of the following finds row sums for each level of a grouping var

1.	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)The question was posed to me in examination.This is a very interesting question from Commands in portion Commands, Packages, Visualizing Data and Linear Regression of R Programming
Answer» Correct choice is (b) rowsum(x, group, reorder = TRUE, …) Explanation: rowsum compute column SUMS across ROWS of a numeric matrix-like object for each LEVEL of a grouping VARIABLE.

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