colmean, colmin, colmax, colrange, colvar, colsd, colprod, colsum, colna {bigmemory} | R Documentation |
These functions operate on columns of the big.matrix
.
colmean(x, cols, na.rm) colmin(x, cols, na.rm) colmax(x, cols, na.rm) colrange(x, cols, na.rm) colvar(x, cols, na.rm) colsd(x, cols, na.rm) colsum(x, cols, na.rm) colprod(x, cols, na.rm) colna(x, cols)
x |
a big.matrix . |
cols |
a scalar or vector of column(s) to be summarized. |
na.rm |
if TRUE , remove NA values before summarizing. |
These functions essentially apply summary functions to each column (or
each specified column) of the big.matrix
in turn.
For colrange
, a matrix with two columns and length(cols)
rows; column 1 contains the minimum, and column 2 contains the maximum for
that column. The other functions return vectors of length length(cols)
.
John W. Emerson and Michael J. Kane
x <- as.big.matrix(matrix(sample(1:10, 20, replace=TRUE), 5, 4)) colnames(x) <- c("a", "b", "c", "d") x[,] mean(x) colmean(x) colmin(x) colmin(x, 1) colmax(x) colmax(x, "b") colsd(x) colrange(x) range(x) colsum(x) colprod(x)