# effects {stats}

### Description

Returns (orthogonal) effects from a fitted model, usually a linear model. This is a generic function, but currently only has a methods for objects inheriting from classes `"lm"`

and `"glm"`

.

### Usage

effects(object, ...) ## S3 method for class 'lm': effects((object, set.sign = FALSE, ...))

### Arguments

- object
- an R object; typically, the result of a model fitting function such as
`lm`

. - set.sign
- logical. If
`TRUE`

, the sign of the effects corresponding to coefficients in the model will be set to agree with the signs of the corresponding coefficients, otherwise the sign is arbitrary. - ...
- arguments passed to or from other methods.

### Details

For a linear model fitted by `lm`

or `aov`

, the effects are the uncorrelated single-degree-of-freedom values obtained by projecting the data onto the successive orthogonal subspaces generated by the QR decomposition during the fitting process. The first r (the rank of the model) are associated with coefficients and the remainder span the space of residuals (but are not associated with particular residuals).

Empty models do not have effects.

### Values

A (named) numeric vector of the same length as `residuals`

, or a matrix if there were multiple responses in the fitted model, in either case of class `"coef"`

.

The first r rows are labelled by the corresponding coefficients, and the remaining rows are unlabelled. Note that in rank-deficient models the corresponding coefficients will be in a different order if pivoting occurred.

### References

Chambers, J. M. and Hastie, T. J. (1992) *Statistical Models in S.* Wadsworth & Brooks/Cole.

### See Also

### Examples

Documentation reproduced from R 3.0.2. License: GPL-2.