# common.shared: Compute a common shared environment matrix In MESS: Miscellaneous Esoteric Statistical Scripts

## Description

Compute the common shared environment matrix for a set of related subjects. The function is generic, and can accept a pedigree, or pedigreeList as the first argument.

## Usage

 ```1 2 3 4 5 6 7``` ```common.shared(id, ...) ## S3 method for class 'pedigreeList' common.shared(id, ...) ## S3 method for class 'pedigree' common.shared(id, ...) ```

## Arguments

 `id` either a pedigree object or pedigreeList object `...` Any number of optional arguments. Not used at the moment

## Details

When called with a pedigreeList, i.e., with multiple families, the routine will create a block-diagonal-symmetric ‘bdsmatrix’ object. Since the [i,j] value of the result is 0 for any two unrelated individuals i and j and a ‘bdsmatix’ utilizes sparse representation, the resulting object is often orders of magnitude smaller than an ordinary matrix. When called with a single pedigree and ordinary matrix is returned.

## Value

a matrix of shared environment coefficients

## Author(s)

Claus Ekstrom [email protected]

`pedigree`, `kinship`,
 ```1 2 3 4 5 6 7``` ```library(kinship2) test1 <- data.frame(id =c(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14), mom =c(0, 0, 0, 0, 2, 2, 4, 4, 6, 2, 0, 0, 12, 13), dad =c(0, 0, 0, 0, 1, 1, 3, 3, 3, 7, 0, 0, 11, 10), sex =c(1, 2, 1, 2, 1, 2, 1, 2, 1, 1, 1, 2, 2, 2)) tped <- with(test1, pedigree(id, dad, mom, sex)) common.shared(tped) ```