summary.stat: Basic statistics for "big.matrix" objects.

In biganalytics: A library of utilities for big.matrix objects of package bigmemory.

Description

These functions operate on columns of a big.matrix object.

Usage

colmean(x, cols, na.rm)
colmin(x, cols, na.rm)
min(x, ..., na.rm)
colmax(x, cols, na.rm)
max(x, ..., na.rm)
colrange(x, cols, na.rm)
range(x, ..., na.rm)
colvar(x, cols, na.rm)
colsd(x, cols, na.rm)
colsum(x, cols, na.rm)
sum(x, ..., na.rm)
colprod(x, cols, na.rm)
prod(x, ..., na.rm)
colna(x, cols)

Arguments

x	a big.matrix object.
cols	a scalar or vector of column(s) to be summarized.
na.rm	if TRUE, remove NA values before summarizing.
...	options associated with the correspoding default R function

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

bigmemory

Examples

x <- as.big.matrix(
  matrix( sample(1:10, 20, replace=TRUE), 5, 4, 
          dimnames=list( NULL, 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)

biganalytics documentation built on May 2, 2019, 4:45 p.m.