# anchors.order: Calculate frequency of vignette orderings In anchors: Statistical analysis of surveys with anchoring vignettes

## Description

Calculate frequency of vignette orderings

## Usage

 ```1 2``` ``` anchors.order(formula, data, ties = c("set", "nominal", "random", "mset"), subset, na.action = na.omit) ```

## Arguments

 `formula` A list of named formulas giving a symbolic description of the model to be fit. See Details below. `data` A data frame or matrix. See Details below. `ties` "set": Groups ties as sets "nominal": Breaks ties by order of vignettes given "random": Breaks ties randomly `subset` Logical expression indicating elements or rows to keep: missing values are taken as false; equivalent to function `subset`. `na.action` Specify the "NA action" which should be applied to 'data'. Default is R standard option 'na.omit'; can also be set to 'na.fail'.

## Details

The formula syntax is designed to allow the same list of formulas to be used for both anchors and chopit and anchors.order. If a user would like to use exactly the same cases with `chopit` as with `anchors.order` (i.e., drop cases with any missing responses or missing `cpolr` values), and vise versa (i.e., also drop any case with missing values in the `tau=`, `tau1=` formulae), then the user should use the same list of formula for all methods and use the option `anchors.options(delete="maximal")`. See example below.

Only options relevant to `anchors.order` are discussed here.

The named list() of formulas may include

self: LHS self-response variable; RHS is simply 1 (needed to define a formula); actually anything can be put on the RHS, and it will not by default be used.

vign: vignette responses, bound together by cbind (as in glm binomial syntax), with ONLY '~ 1' as RHS of equation (formulas must have RHS).

Example:

 ```1 2 3``` ``` fo <- list(self = xsayself ~ 1, vign = cbind(xsay3,xsay1) ~ 1) ```

One can also use a single formula as a short hand: specifying

fo <- self ~ vign1 + vign2

is equivalent to

 ```1 2 3``` ``` fo <- list(self = self ~ 1 vign = cbind(vign1,vign2) ~ 1) ```

All of the response variables must be in the form of consequetive non-negative numeric integers, i.e., 1, 2, ... K.

** `anchors` currently does not support factor responses.**

The method="B" and "C" requires that cases with any response that is missing be dropped. Any cases with missing values the covariates specified in the `cpolr=` formula are also dropped. BUT by default these methods ignore missing values in the covariates specified by `tau=`, `tau1=`, or the right hand side of `self=`.

## Value

Each vignette is represented by the integer indexing it's place as passed to the function. For example, let

fo <- list(vign = cbind(vign1,vign2,vign3))

then 1=vign1, 2=vign2, 3=vign3. In the case of an anchors.order object produced with the option ties="set", tied variables are represented by being included in brackets.

 ```1 2``` ``` anchors.order( fo, data, ties="set") ```

then a row with "{1,3},2" indicates that vign1 and vign3 are tied, and vign2 has a higher value than both of them.

 `labels` Description of order of vignettes `freq` Frequency of order of vignettes

## Note

Related materials and worked examples are available at http://wand.stanford.edu/anchors/

## Author(s)

Jonathan Wand and Dan Hopkins

## References

Wand, Jonathan; Gary King; and Olivia Lau. (2007) “Anchors: Software for Anchoring Vignettes”. Journal of Statistical Software. Forthcoming. copy at http://wand.stanford.edu/research/anchors-jss.pdf

Wand, Jonathan and Gary King. (2007) Anchoring Vignetttes in R: A (different kind of) Vignette copy at http://wand.stanford.edu/anchors/doc/anchors.pdf

Gary King and Jonathan Wand. "Comparing Incomparable Survey Responses: New Tools for Anchoring Vignettes," Political Analysis, 15, 1 (Winter, 2007): Pp. 46-66, copy at http://gking.harvard.edu/files/abs/c-abs.shtml.

`anchors`,`barplot.anchors.order`
 ``` 1 2 3 4 5 6 7 8 9 10 11 12``` ```data(mexchn) z <- anchors.order( ~ xsay1 + xsay2 + xsay3 + xsay4 + xsay5, mexchn, ties = "set") summary(z,top=10,digits=3) barplot(z) z <- anchors.order( ~ xsay5 + xsay4 + xsay3 + xsay2 + xsay1, mexchn, ties = "set") summary(z,top=10,digits=3) ## other option z <- anchors.order( ~ xsay5 + xsay4 + xsay3 + xsay2 + xsay1, mexchn, ties = "nominal") summary(z,top=10,digits=3) barplot(z) ```