Column-wise differences {Rfast}

Column-wise differences

Description

Column-wise differences.

Usage

coldiffs(x)

Arguments

x

A matrix with numbers.

Details

This function simply does this function x[, -1] - x[, -k], where k is the last column of the matrix x. But it does it a lot faster. That is, 2nd column - 1st column, 3rd column - 2nd column, and so on.

Value

A matrix with one column less containing the differences between the successive columns.

Author(s)

Manos Papadakis

R implementation and documentation: Manos Papadakis <[e-mail]>.

See Also

Dist, dista, colmeans

Examples

x <- matrix( rnorm(50 * 10), ncol = 10 )
res<-coldiffs(x)

x<-NULL