colmean, colmin, colmax, colrange, colvar, colsd, colprod, colsum, colna {bigmemory}R Documentation

Basic statistics for “big.matrix” objects.

Description

These functions operate on columns of the big.matrix.

Usage

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)

Arguments

x a big.matrix.
cols a scalar or vector of column(s) to be summarized.
na.rm if TRUE, remove NA values before summarizing.

Details

These functions essentially apply summary functions to each column (or each specified column) of the big.matrix in turn.

Value

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).

Author(s)

John W. Emerson and Michael J. Kane

See Also

big.matrix

Examples

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)

[Package bigmemory version 3.10 Index]