This function creates the difference operator matrix delta for subtracting a matrix row from the other matrix rows.

## Usage

delta(J, i)

## Arguments

J

The number of matrix rows.

i

The row number to which respect differences are computed.

## Value

A matrix with J-1 rows.

## Details

Given a matrix x with J rows, then delta(i,J) %*% x computes differences with respect to row i.

## Examples

J <- 2
x <- matrix(1, nrow = J, ncol = 2)
RprobitB:::delta(J, 1) %*% x
#>      [,1] [,2]
#> [1,]    0    0