trace plot of MCMC iterates, posterior density of legislators' ideal points
Description
Produces a trace plot of the MCMC samples from the posterior density of
legislators' ideal
points.
Usage
1 2 3 
Arguments
object 
an object of class 
legis 
a vector of either the names of legislators (or

d 
numeric, either a scalar or a vector of length two, the dimension(s) to be traced. 
conf.int 
numeric, the level of the confidence interval on the posterior mean to be plotted. 
multi 
logical, multiple plotting panels, one per legislators? If 
burnin 
of the recorded MCMC samples, how many to discard as
burnin? Default is 
span 
numeric, a proportion, the 
legendLoc 
numeric or character, and possibly a vector,
specifying where to place the legend when 
Details
Produces a trace plot showing the history of the MCMC
iterations for the ideal point of each of the legislators (partially)
named in legis
. For d=1
, each trace plot includes a
trace over iterations, the cumulative mean, a moving average, the
MCMCbased estimate of the mean of the posterior, and a confidence
interval (specified by conf.int
) around the mean of the
posterior (using the estimated quantiles
) of
the respective MCMC iterates). All of these values are calculated
discarding the initial burnin
iterations.
When d
is a vector of length two, a 2dimensional trace plot is
displayed, with the d[1]
dimension on the horizontal axis, and
the d[2]
dimension on the vertical axis.
When d=1
, a legend will be placed on the plot; the option
legendLoc
controls the placing of the legend. legendLoc
may be a vector, specifying a unique legend location for each
requested trace plots. If
legendLoc
is of length 1, it will be rep
licated
to have length equal to the number of requested trace plots.
See Also
ideal
; pmatch
for matching
legislators' names. See legend
for valid options to
legendLoc
.
Examples
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22  data(s109)
f < system.file("extdata","id1.rda",package="pscl")
load(f)
tracex(id1,legis="KENN")
## n.b., no such legislator named Thomas Bayes
tracex(id1,legis=c("KENN","BOX","KYL","Thomas Bayes"))
f < system.file("extdata","id2.rda",package="pscl")
load(f)
tracex(id2,d=1,legis=c("KENNEDY","BOXER","KYL","Thomas Bayes"))
tracex(id2,d=2,legis=c("KENNEDY","BOXER","KYL","Thomas Bayes"))
tracex(id2,d=1:2,
legis=c("KENNEDY","BOXER","KYL","Thomas Bayes"))
## partial matching
tracex(id2,d=1:2,
legis=c("KENN","BOX","BID","SNO","SPEC","MCCA","KYL",
"Thomas Bayes"),
multi=TRUE)
