Calculates the mean for each row (column) in a matrix

Calculates the mean for each row (column) in a matrix.

rowMeans2(x, rows = NULL, cols = NULL, na.rm = FALSE, refine = TRUE,
  dim. = dim(x), ..., useNames = TRUE)

colMeans2(x, rows = NULL, cols = NULL, na.rm = FALSE, refine = TRUE,
  dim. = dim(x), ..., useNames = TRUE)

Arguments

x

An NxK matrix or, if dim. is specified, an N * K vector.

rows

A vector indicating subset of rows to operate over. If NULL, no subsetting is done.

cols

A vector indicating subset of columns to operate over. If NULL, no subsetting is done.

na.rm

If TRUE, missing values are excluded.

refine

If TRUE and x is numeric, then extra effort is used to calculate the average with greater numerical precision, otherwise not.

dim.

An integer vector of length two specifying the dimension of x, also when not a matrix. Comment: The reason for this argument being named with a period at the end is purely technical (we get a run-time error if we try to name it dim).

...

Not used.

useNames

If TRUE (default), names attributes of the result are set, otherwise not.

Value

Returns a numeric vector of length N (K).

Details

The implementation of rowMeans2() and colMeans2() is optimized for both speed and memory.

Author

Henrik Bengtsson