# R
package **estimability**: Support for determining
estimability of linear functions

## Features

- A
`nonest.basis()`

function is provided that determines a
basis for the null space of a matrix. This may be used in conjunction
with `is.estble()`

to determine the estimability (within a
tolerance) of a given linear function of the regression coefficients in
a linear model.
- A set of
`epredict()`

methods are provided for
`lm`

, `glm`

, and `mlm`

objects. These
work just like `predict()`

, except an `NA`

is
returned for any cases that are not estimable. This is a useful
alternative to the generic warning that “predictions from rank-deficient
models are unreliable.”
- A function
`estble.subspace()`

that projects a set of
linear functions onto an

estimable subspace (possibly of smaller dimension). This can be useful
in creating a set of estimable contrasts for joint testing.
- Package developers may wish to import this package and incorporate
estimability checks for their
`predict`

methods.

## Installation

- To install latest version from CRAN, run

`install.packages("estimability")`

Release notes for the latest CRAN version are found at https://cran.r-project.org/package=estimability/NEWS
– or do `news(package = "estimability")`

for notes on the
version you have installed.

- To install the latest development version from Github, have the
newest
**devtools** package installed, then run

`devtools::install_github("rvlenth/estimability", dependencies = TRUE)`

For latest release notes on this development version, see the NEWS
file