stack.Lexis {Epi} | R Documentation |
stack.Lexis
produces a stacked object suited for analysis of
several transitions simultaneously.
## S3 method for class 'Lexis': stack(x, ...) tmat( x, ... ) ## S3 method for class 'Lexis': tmat(x, ...)
x |
A Lexis object.
|
... |
Not used. |
tmat.Lexis
returns a square transition matrix, classified by the
levels of lex.Cst
and lex.Xst
, it has a 1 for every
transition occurring and NA
in all oter entries.
stack.Lexis
returns a dataframe to be used for analysis of
multistate data when all transitions are modelled together, for example
if some parameters are required to be the same for different transitions.
The dataframe has same variables as the original Lexis
object,
but with each record duplicated as many times as there are possible
exits from the current state, lex.Cst
. Two variables are added:
lex.Fail
, an indicator of wheter an event for the transition
names in lex.Tr
has occurred or not. lex.Tr
is a factor
with levels made up of combinations of the levels of lex.Cst
and
lex.Xst
that do occur together in x
, joined by a
"->
".
Bendix Carstensen, bxc@steno.dk, www.biostat.ku.dk/~bxc
data(DMlate) str(DMlate) dml <- Lexis( entry=list(Per=dodm, Age=dodm-dobth, DMdur=0 ), exit=list(Per=dox), exit.status=factor(!is.na(dodth),labels=c("DM","Dead")), data=DMlate ) dmi <- cutLexis( dml, cut=dml$doins, new.state="Ins", pre="DM" ) summary( dmi ) ls.dmi <- stack( dmi ) str( ls.dmi ) # Check that all the transitions and person-years got across. with( ls.dmi, rbind( table(lex.Fail,lex.Tr), tapply(lex.dur,lex.Tr,sum) ) )