R: Plot Method for "lmrob" Objects

plot.lmrob {robustbase} | R Documentation

## Plot Method for "lmrob" Objects

### Description

Diagnostic plots for elements of class lmrob

### Usage

    ## S3 method for class 'lmrob'
    plot(x, which = 1:5,
         caption = c("Standardized residuals vs. Robust Distances",
       "Normal Q-Q vs. Residuals", "Response vs. Fitted Values",
       "Residuals vs. Fitted Values" , "Sqrt of abs(Residuals) vs. Fitted Values"),
       panel = if(add.smooth) panel.smooth else points,
       sub.caption = deparse(x$call), main = "",
       compute.MD = TRUE,
       ask = prod(par("mfcol")) < length(which) && dev.interactive(),
       id.n = 3, labels.id = names(residuals(x)), cex.id = 0.75,
       label.pos = c(4,2), qqline = TRUE, add.smooth = getOption("add.smooth"),
       ..., p=0.025)

### Arguments

`x` | an object as created by `lmrob`
`which` | integer number between 1 and 5 to specify which plot is desired
`caption` | Caption for the different plots
`panel` | panel function. The useful alternative to `points`, `panel.smooth` can be chosen by `add.smooth = TRUE`.
`main` | main title
`sub.caption` | sub titles
`compute.MD` | logical indicating if the robust Mahalanobis distances should be recomputed, using `covMcd()` when needed, i.e., if `which` contains `1`.
`ask` | waits for user input before displaying each plot
`id.n` | number of points to be labelled in each plot, starting with the most extreme.
`labels.id` | vector of labels, from which the labels for extreme points will be chosen. `NULL` uses observation numbers.
`cex.id` | magnification of point labels.
`label.pos` | positioning of labels, for the left half and right half of the graph respectively.

`qqline` | logical indicating if a `qqline()` should be added to the normal Q-Q plot.
`add.smooth` | logical indicating if a smoother should be added to most plots; see also `panel` above.
`...` | optional arguments for `par`, `title`, etc.
`p` | threshold for distance-distance plot

### Details

if `compute.MD = TRUE` and the robust Mahalanobis distances need to be computed, they are stored (“cached”) with the object `x` when this function has been called from top-level.

### References

Robust diagnostic plots as in Rousseeuw and van Zomeren (1990), see ‘References’ in `ltsPlot`.

### See Also

`lmrob`, also for examples, `plot.lm`.

### Examples

    data(starsCYG)
    ## Plot simple data and fitted lines
    plot(starsCYG)
     lmST <-    lm(log.light ~ log.Te, data = starsCYG)
    RlmST <- lmrob(log.light ~ log.Te, data = starsCYG)
    RlmST
    abline(lmST, col = "red")
    abline(RlmST, col = "blue")

    op <- par(mfrow = c(2,2), mgp = c(1.5, 0.6, 0), mar= .1+c(3,3,3,1))
    plot(RlmST, which = c(1:2, 4:5))
    par(op)

[Package robustbase version 0.95-0 Index]