lmrob..D..fit {robustbase} | R Documentation

## Compute Design Adaptive Scale estimate

### Description

This function calculates a Design Adaptive Scale estimate for a given MM-estimate. This is supposed to be a part of a chain of estimates like `SMD` or `SMDM`.

### Usage

    lmrob..D..fit(obj, x=obj$x, control = obj$control,
                  mf = obj$model, method = obj$control$method)

### Arguments

`obj` | `lmrob`-object based on which the estimate is to be calculated.
`x` | the design matrix; if `missing`, the method tries to get it from `obj$x` and if this fails from `obj$model`.
`control` | list of control parameters, as returned by `lmrob.control`.
`mf` | (optional) a model frame as returned by `model.frame`, used only to compute outlier statistics, see `outlierStats`.
`method` | optional; the `method` used for obj computation.

### Details

This function is used by `lmrob.fit` and typically not to be used on its own. Note that `lmrob.fit()` specifies `control` potentially differently than the default, but does use the default for `method`.

### Value

The given `lmrob`-object with the following elements updated:

`scale` | The Design Adaptive Scale estimate
`converged` | `TRUE` if the scale calculation converged, `FALSE` other.

### Author(s)

Manuel Koller

### References

Koller, M. and Stahel, W.A. (2011), Sharpening Wald-type inference in robust regression for small samples, Computational Statistics & Data Analysis 55(8), 2504–2515.

### See Also

`lmrob.fit`, `lmrob`

### Examples

    data(stackloss)
    ## Compute manual SMD-estimate:
    ## 1) MM-estimate
    m1 <- lmrob(stack.loss ~ ., data = stackloss)
    ## 2) Add Design Adaptive Scale estimate
    m2 <- lmrob..D..fit(m1)
    print(c(m1$scale, m2$scale))

    summary(m1)
    summary(m2) ## the covariance matrix estimate is also updated

[Package robustbase version 0.92-7 Index]