# load qtl2 package for data and genoprob calculation
library(qtl2)
# read data
iron <- read_cross2(system.file("extdata", "iron.zip", package="qtl2"))
# insert pseudomarkers into map
map <- insert_pseudomarkers(iron$gmap, step=1)
# calculate genotype probabilities
probs <- calc_genoprob(iron, map, error_prob=0.002)
# grab phenotypes and covariates; ensure that covariates have names attribute
pheno <- iron$pheno
covar <- match(iron$covar$sex, c("f", "m")) # make numeric
names(covar) <- rownames(iron$covar)
Xcovar <- get_x_covar(iron)
# perform genome scan
out <- scan1(probs, pheno, addcovar=covar, Xcovar=Xcovar)
# plot the results for selected chromosomes
chr <- c(2,7,8,9,15,16)
ggplot_scan1(out, map, lodcolumn=1:2, chr=chr, col=c("darkslateblue","violetred"),
legend.position=c(0.1,0.9))
# plot just one chromosome
ggplot_scan1(out, map, chr=8, lodcolumn=1:2, col=c("darkblue","violetred"))
# can also use autoplot from ggplot2
# lodcolumn can also be a column name
library(ggplot2)
autoplot(out, map, chr=8, lodcolumn=c("liver","spleen"), col=c("darkblue","violetred"))
Run the code above in your browser using DataLab