unstructured {asreml} | R Documentation

## General structure variance models.

### Description

General correlation and covariance models.

### Usage

    cor(obj, init=NA)

    corv(obj, init=NA)

    corh(obj, init=NA)

    corb(obj, b=1, init=NA)

    corbv(obj, init=NA)

    corbh(obj, init=NA)

    corg(obj, init=NA)

    corgv(obj, init=NA)

    corgh(obj, init=NA)

    diag(obj, init=NA)

    us(obj, init=NA)

    chol(obj, k=1, init=NA)

    ante(obj, k=1, init=NA)

    sfa(obj, k=1, init=NA)

    facv(obj, k=1, init=NA)

    fa(obj, k=1, init=NA)

    rr(obj, k=1, init=NA)

### Arguments

`obj` | A factor in `data`.
`init` | A vector of initial values (correlation parameters followed by variance parameters) with an optional `names` attribute from the set {P, U, F} specifying the boundary constraint as positive, unconstrained or fixed, respectively.
`b` | Number of (sub-diagonal) bands in banded correlation models.
`k` | Order of the model (`chol, ante`) or number of factors (`sfa, facv, fa, rr`).

### Details

The class of general variance models includes the simple, banded and general correlation models (`cor`, `corb`, `corg`), the diagonal, unstructured, Cholesky and antedependence variance models (`diag`, `us`, `chol`, `cholc`, `ante`) and the factor analytic structures (`sfa`, `facv`, `fa`).

### Functions

- `asr_corv`: Simple correlation model, homogeneous variance form.

- `asr_corh`: Simple correlation model, heterogeneous variance form.

- `asr_corb`: Banded correlation model with `b` bands.

- `asr_corbv`: Banded correlation model with `b` bands, homogeneous variance form.

- `asr_corbh`: Banded correlation model with `b` bands, heterogeneous variance form.

- `asr_corg`: General correlation model.

- `asr_corgv`: General correlation model, homogeneous variance form.

- `asr_corgh`: General correlation model, heterogeneous variance form.

- `asr_diag`: Diagonal variance model.

- `asr_us`: Unstructured variance model.

- `asr_chol`: Cholesky variance model of order `k`.

- `asr_ante`: Antedependence variance model of order `k`.

- `asr_sfa`: Factor analytic model with `k` factors; the variance-covariance matrix is modelled on the correlation scale.

- `asr_facv`: Factor analytic model with `k` factors; the variance-covariance matrix is modelled on the covariance scale.

- `asr_fa`: Factor analytic model with `k` factors; sparse formulation where `k` “extra” levels are inserted in the mixed model equations.

- `asr_rr`: Factor analytic model with `k` factors; reduced rank formulation of `fa()` where the default boundary constraints for the specific variances are set to Fixed.

[Package asreml version 4.1.0.176 Index]