# ranks

##### Quantile Regression Ranks

Function to compute ranks from the dual (regression rankscore) process.

- Keywords
- regression

##### Usage

`ranks(v, score="wilcoxon", tau=0.5, trim = NULL)`

##### Arguments

- v
object of class

`"rq.process"`

generated by`rq()`

- score
The score function desired. Currently implemented score functions are

`"wilcoxon"`

,`"normal"`

, and`"sign"`

which are asymptotically optimal for the logistic, Gaussian and Laplace location shift models respectively. The "normal" score function is also sometimes called van der Waerden scores. Also implemented are the`"tau"`

which generalizes sign scores to an arbitrary quantile,`"interquartile"`

which is appropriate for tests of scale shift,`normalscale`

for Gaussian scale shift,`halfnormalscale`

for Gaussian scale shift only to the right of the median, and`lehmann`

for Lehmann local alternatives. See Koenker (2010) for further details on the last three of these scores.- tau
the optional value of

`tau`

if the`"tau"`

score function is used.- trim
optional trimming proportion parameter(s) -- only applicable for the Wilcoxon score function -- when one value is provided there is symmetric trimming of the score integral to the interval

`(trim, 1-trim)`

, when there are two values provided, then the trimming restricts the integration to`(trim[1], trim[2])`

.

##### Details

See GJKP(1993) for further details.

##### Value

The function returns two components. One is the ranks, the other is a scale factor which is the \(L_2\) norm of the score function. All score functions should be normalized to have mean zero.

##### References

Gutenbrunner, C., J. Jureckova, Koenker, R. and Portnoy,
S. (1993) Tests of linear hypotheses based on regression
rank scores, *Journal of Nonparametric Statistics*, (2), 307--331.

Koenker, R. Rank Tests for Heterogeneous Treatment Effects with Covariates, preprint.

##### See Also

##### Examples

```
# NOT RUN {
data(stackloss)
ranks(rq(stack.loss ~ stack.x, tau=-1))
# }
```

*Documentation reproduced from package quantreg, version 5.54, License: GPL (>= 2)*