R: Indicator matrix

In {ggm} | R Documentation

## Indicator matrix

### Description

Finds the indicator matrix of the zeros of a matrix.

### Usage

    In(A)

### Arguments

`A` | a matrix.

### Details

The indicator matrix is a matrix of zeros and ones which has a zero element iff the corresponding element of `A` is (exactly) zero.

### Value

a matrix of the same dimensions as `A`.

### Author(s)

Giovanni M. Marchetti

### References

Wermuth, N. \& Cox, D.R. (2004). Joint response graphs and separation induced by triangular systems. J.R. Statist. Soc. B, 66, Part 3, 687-717.

### See Also

`DAG`, `inducedCovGraph`, `inducedConGraph`

### Examples

    ## A simple way to find the overall induced concentration graph
    ## The DAG on p. 198 of Cox & Wermuth (1996)
    amat <- DAG(y1 ~ y2 + y3, y3 ~ y5, y4 ~ y5)
    A <- edgematrix(amat)
    In(crossprod(A))

[Package ggm version 2.3 Index]