addGE: Assess combinations of univariate multic objects
In multic: Quantitative Linkage Analysis Tools using the Variance Components Approach

Description Usage Arguments Value Side Effects References See Also Examples

Determine whether there is any evidence that running a multivariate multic model will significantly increase the evidence of a genetic effect.

1 2	addGE(multic.objs, combine=2, plotit=FALSE, ibd.dist, statistic=c("lrt", "wald"), legend=TRUE, ylim=NULL, ...)

`multic.objs`	A list of 1-trait multic objects.
`combine`	Indicate how many traits should be examined together. The program will then look at all N traits choose 'combine'.
`plotit`	Logical, default=FALSE. If TRUE, a LOD plot is generated with a separate line for each combination of traits.
`ibd.dist`	The default is to use the distances from the first multic object. This options allows the user to provide a different set of distances.
`statistic`	Character, default="lrt". This determines whether the Wald statistic (MG/SE) or the LRT is used when combining the traits.
`legend`	Logical, default=TRUE. If TRUE and if plotit=TRUE then a legend is automatically provided.
`ylim`	The extremes of the range of the y-axis to pass to the plot function.
`...`	Allows for graphical parameters to be passed to the plot function (only applicable when plotit=TRUE).

A data frame is returned if the function is assigned to new object. Included are the various combinations (listed in order 1-N), the Chi-square statistic, the p-value, the distance, and the LOD score.

If plotit=T, a plot is generated on the current graphical device.

M. de Andrade, C. Olswold, J.P. Slusser, L.A.Tordsen, E.J. Atkinson, K.G. Rabe, and S.L.Slager. Identification of genes involved in alcohol consumption and cigarette smoking. BMC Genetics, 6:S112, 2005.

multic, gene.eff

## Not run: 
add2 <- addGE(list(bmi10, dia10, sys10), combine = 2, plotit = T, ylim=c(0,8), legend=F)
add3 <- addGE(list(bmi10, dia10, sys10), combine = 3, plotit = F)
lines(add3$cM, add3$lod, col=4, lwd=2, lty=4)
key(corner=c(0,1), lines=list(lwd=2, col=1:4, lty=1:4),
    text=list(c('BMI-Dia','BMI-Sys','Dia-Sys','BMI-Dia-Sys'), col=1:4))

## End(Not run)