xdistResdiff: Residual Differences for Near Replicates: Tabulate and Test
In regr0: Building regression models

Description Usage Arguments Details Value Author(s) References See Also Examples

A test for the completeness of a linear regression model can be performed based on comparing the differences of residuals for pairs of observations that are close to each other to the estimated standard deviation of the

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xdistResdiff(object, perc = c(3, 10, 80), trim = 0.1,
  nmax = 100, nsim = 100, out = "aggregate")
xdistResscale(x, perc = c(3, 10, 90), trim = 1/6)

`object`	an object containing the result of fitting a linear model by `regr`
`x`	an object produced by `xdistResdiff`
`perc`	Percentage points to define distance classes
`trim`	Trimming proportion for calculating means of absolute residual differences
`nmax`	maximal number of observations to form pairs
`nsim`	number of simulations for determining the null distribution of test statistics
`out`	determines the value of `xdistResdiff`: if `=="aggregate"` (the default), the value will be produced by calling `xdistResscale`, otherwise, all x distances and respective residual differences will be returned.

See package vignette.

For xdistResdiff with out="aggregate" and xdistResscale, a matrix is returned with a row for each class of x distances and the columns

`xdist`	mean x distance
`rdiff.mean`	absolute differences of residuals for pairs of observations in the distance class, averaged over the class
`rdiff.simmean`	mean of (trimmed) means for simulated data
`rdiff.se`	standard error of (trimmed) means as obtained from simulation

The matrix carries along the following attributes:

`perc`	given argument `perc`
`xd.classlim`	the actual class limits corresponding to `perc`
`trim`	given argument `trim`
`rdiff.grandmean`	overall mean of absolute residual differences
`p-values`	p values for the classes as obtained from simulation, and p-value for the sum of squares statistic
`class`	The value has S3 class `xdistResscale` and `matrix`

If xdistResdiff with out different from "aggregate", then a data.frame is returned containing a row for each pair of observations and the columns

`id1, id2`	the labels of the two observations
`xdist`	the x distance between the two observations
`resdiff`	the difference of residuals for the two observations

The value has S3 class xdistResdiff and data.frame.

Werner A. Stahel, ETH Zurich

See package vignette.

plot.xdistResscale

data(d.blast)
rr <- regr(tremor~distance+charge, data=d.blast)
## an inadequate model!x
xdistResdiff(rr)
xdrd <- xdistResdiff(rr, out="all")
showd(xdrd[,1:10])
xdistResscale(xdrd)
## same as first call of  xdiffResdiff