dropRollCall {pscl} | R Documentation |
Drop user-specified elements of rollcall object, returning a roll call object.
dropRollCall(object, dropList)
object |
an object of class rollcall |
dropList |
a list (or alist ) with
some (or all) of the following components:
codes object$codes ,
indicating the set of entries in object$votes to be set to
NA . If numeric, then codes indicates the entries in
object$votes that will be set to NA .lop object . Roll calls with lop
or fewer legislators voting in the minority are dropped.legisMin object . Legislators with
legisMin or fewer votes are dropped.dropLegis expression that evaluates to
mode logical , vector of length equal to the number of
legislators represented in object . The expression is evaluated
in the legis.data component of the rollcall object .
Legislators for whom the expression evaluates to TRUE are
dropped.dropVotes expression that evaluates to
mode logical , vector of length equal to the number of
rollcalls represented in object . The expression is evaluated
in the votes.data component of the rollcall object .
Rollcalls for which the expression evaluates to TRUE are
dropped. |
It is often desirable to restrict the analysis of roll call
data in various ways. For one thing, unanimous votes provide no
information discriminating among legislators: hence, a useful
default for summary and analysis is dropList=list(lop=0)
.
See the examples for other possibilities, limited only by the
information supplied in legis.data
and votes.data
.
An object of class rollcall
with components modified by
the subsetting indicated in the dropList
.
With the exception of codes
, each component of
dropList
generates a vector of mode logical
,
either with respect to legislators or votes. These logical
vectors are then combined element-wise, such that if any one of
the subseting restrictions is TRUE
for a particular
legislator or vote, then that legislator or vote is dropped. Some
summaries are reported to the console along the way.
When dropList
uses the dropLegis
or dropVotes
components then dropList
should be constructed as an
alist
command; this ensures that the
dropLegis
and dropVotes
components of
dropList
are objects of mode expression
, and
eval
uated to mode logical
in the
legis.data
and vote.data
environment
s by
the function, if possible (rather than being evaluated immediately in
the environment calling dropRollCall
or constructing
dropList
). See the examples. This is not entirely
satisfactory, and behavior more like the subset
argument in
function lm
would be preferable.
Simon Jackman jackman@stanford.edu
dropUnanimous
, summary.rollcall
,
ideal
, alist
.
data(s109) s109.working <- dropRollCall(s109, dropList=list(lop=0)) s109.working <- dropRollCall(s109, dropList=list(lop=0, code="notInLegis")) s109.working <- dropRollCall(s109, dropList=list(lop=3, code="notInLegis")) ## note use of alist, since dropLegis is an expression dropList <- alist(lop=3, dropLegis=party!="D", code="notInLegis") s109.working <- dropRollCall(s109,dropList=dropList) ## Not run: ## read 102nd House from Poole web site h102 <- readKH("ftp://voteview.ucsd.edu/dtaord/hou102kh.ord") ## drop President from roll call matrix h102 <- dropRollCall(h102, dropList=alist(dropLegis=state=="USA")) ## End(Not run)