| arithscanperm {qtl} | R Documentation |
Add or subtract LOD scores in permutation results from
scanone or scantwo.
perm1+perm2 perm1-perm2
perm1, perm2 |
Permutation results from
scanone or scantwo, on the
same set of chromosomes and markers. |
This is used to calculate the sum or difference of LOD scores of two
sets of permutation results from scanone or
scantwo. One must be careful to ensure that the
permutations are perfectly linked, which
will require the use of set.seed.
The same data structure as the input objects, with LOD scores added or subtracted.
Karl W Broman, kbroman@biostat.wisc.edu
data(fake.bc)
fake.bc <- calc.genoprob(fake.bc, step=2.5)
# covariates
ac <- fake.bc$pheno[,c("sex","age")]
ic <- fake.bc$pheno[,"sex"]
# set seed
theseed <- round(runif(1, 1, 10^8))
set.seed(theseed)
# permutations with additive but not the interactive covariate
## Not run:
operm.acovar <- scanone(fake.bc, addcovar=ac, n.perm=1000)
## End(Not run)
# re-set the seed
set.seed(theseed)
# permutations with interactive covariate
## Not run:
operm.icovar <- scanone(fake.bc, addcovar=ac, intcovar=ic,
n.perm=1000)
## End(Not run)
# permutation results for the QTL x covariate interaction
operm.gxc <- operm.icovar - operm.acovar
# LOD thresholds
summary(operm.gxc)