join-split function

Joining and splitting of colour classes in RCOX models

Test for joining of two colour classes (of a specific type) by testing if their corresponding parameters are not significantly different. Split a colour class and test how much this changes the fit of the model.

Arguments

• object: An RCOX model, an object of class RCOX
• scope: A specification of colour classes which should be considered for joining/splitting. If NULL, then all colour classes are considered.
• type: Either "ecc" for edge colour classes or "vcc" for vertex colour classes.
• stat: Either "wald" for a Wald statistic or "dev" for deviance statistic.
• details: Control the amount of output

Returns

A list with entries: - tab: A data frame with the test results - cc: A list of colour classes

Note

Note that the keyword 'stat' is not available for split1 because this function expands the current and hence the Wald statistic is not available. Note also that join1 is simply a wrapper for comparecc applied to edge colour classes.

Examples

data(math)
g1     <- ~me:ve:al+al:st:an
m1     <- rcox(gm=g1, data=math)
join1(m1)

gm  = ~al:an:st
vcc = list(~me+st, ~ve+an)
ecc = list(~me:ve+me:al, ~ve:al+al:st)
m2 <- rcox(gm=gm, vcc=vcc, ecc=ecc, data=math, type="rcon")
split1(m2)

See Also

rcox, update, comparecc

Author(s)

Søren Højsgaard, sorenh@math.aau.dk