DNA pattern: distribution of counts

intervalSizes = seq(from=1000, to=12000, by=1000)
par(mfrow=c(4,3))
for(i in 1:length(intervalSizes)) {
size = intervalSizes[i]
intervalHead = seq(from=1, to=dnalen, by=size)
if((intervalHead[length(intervalHead)]+size-1)>dnalen) {
numIntervals = length(intervalHead)-1
} else {
numIntervals = length(intervalHead)
}
palCountsEachInterval = rep(NA, numSegments)
for(intv in 1:numIntervals) {
palCountsEachInterval[intv] = sum(intervalHead[intv]:(intervalHead[intv]+size-1) %in% posvec)
}
if(i %in% seq(1,12,4)) {
ylab = "Frequency"
} else {
ylab = ""
}
if(i %in% 9:12) {
xlab = "Counts per interval"
} else {
xlab = ""
}

hist(palCountsEachInterval, main=paste("interval size ", size, sep=""), xlab=xlab, ylab=ylab)
}