# SSD {stats}

SSD Matrix and Estimated Variance Matrix in Multivariate Models
Package:
stats
Version:
R 3.0.2

### Description

Functions to compute matrix of residual sums of squares and products, or the estimated variance matrix for multivariate linear models.

### Usage

```# S3 method for class 'mlm'
SSD(object, ...)

# S3 methods for class 'SSD' and 'mlm'
estVar(object, ...)
```

### Arguments

object
`object` of class `"mlm"`, or `"SSD"` in the case of `estVar`.
...
Unused

### Values

`SSD()` returns a list of class `"SSD"` containing the following components

`estVar` returns a matrix with the estimated variances and covariances.

SSD
The residual sums of squares and products matrix
df
Degrees of freedom
call
Copied from `object`

`mauchly.test`, `anova.mlm`

### Examples

```# Lifted from Baron+Li:
# "Notes on the use of R for psychology experiments and questionnaires"
# Maxwell and Delaney, p. 497
reacttime <- matrix(c(
420, 420, 480, 480, 600, 780,
420, 480, 480, 360, 480, 600,
480, 480, 540, 660, 780, 780,
420, 540, 540, 480, 780, 900,
540, 660, 540, 480, 660, 720,
360, 420, 360, 360, 480, 540,
480, 480, 600, 540, 720, 840,
480, 600, 660, 540, 720, 900,
540, 600, 540, 480, 720, 780,
480, 420, 540, 540, 660, 780),
ncol = 6, byrow = TRUE,
dimnames = list(subj = 1:10,
cond = c("deg0NA", "deg4NA", "deg8NA",
"deg0NP", "deg4NP", "deg8NP")))

mlmfit <- lm(reacttime ~ 1)
SSD(mlmfit)
estVar(mlmfit)```

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