Description Usage Arguments Details Value Note Author(s) References See Also Examples
Calculate frequency of vignette orderings
1 2 |
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 |
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'. |
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:
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One can also use a single formula as a short hand: specifying
fo <- self ~ vign1 + vign2
is equivalent to
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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=
.
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 |
Related materials and worked examples are available at http://wand.stanford.edu/anchors/
Jonathan Wand and Dan Hopkins
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.
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)
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