vpredict {asreml} | R Documentation

## Functions of variance parameters.

### Description

Form functions of variance components from an `asreml` object.

### Usage

    vpredict(object, xform)

### Arguments

`object` | An `asreml` object.
`xform` | A two-sided formula, where the left-hand side labels the estimate. The right-hand side defines the derived parameter as an algebraic expression. Any of the estimated parameters can be included, represented as `"V1"`, `"V2"`, `"V3"`, ... in the order they appear in `object$vparameters`. Parentheses, and simple functions like `log`, `exp`, `sqrt` are allowed.

### Details

The standard error of the computed value is calculated using the delta method using `deriv()`, which calculates algebraic derivatives for a wide range of expressions. The variance components are represented in the expression by `"V1"`, `"V2"`, `"V3"`, etc.

### Value

A single-row data frame with components:

Estimate

  The result of the algebraic expression.

SE

  The estimated standard error.

[Package asreml version 4.1.0.176 Index]