caloffset = function(genome){
    total_len = sum(as.numeric(genome[,2]))
    offset = 0
    for (i in 1:nrow(genome)) {
        offset = c(offset,offset[i]+genome[i,2])        
    }
    offset    
}

coverage = function(intervals,genome,offset,resolution) {

    nChr = length(offset) - 1
    total_len = offset[nChr+1]
    nbin = as.integer(total_len / resolution)
    cov = numeric(nbin)#coverage
    col = numeric(nbin)#color
    for (i in 1:nChr) {
        d = x[x[,1]==as.character(genome[i,1]),2:3]
        d = ceiling(((d[,1]+d[,2])/2+offset[i])*nbin/total_len)
        t = table(d)
		pos = as.numeric(row.names(t)) 
        cov[pos] = cov[pos] + as.numeric(t)
        col[pos] = i
    }
    list(nbin=nbin,cov=cov,col=col)
}

# plot coverage
# res = genomeView(x,genome,100000)
plotcov = function(res,genome,offset,title,uselog) {
	if (uselog == 'log'){
		res$cov = log10(res$cov+1)
	}
    ymax = max(res$cov)
    #print(ymax)
	par(mar=c(5,5,5,1))
    plot(seq(length(res$cov)),res$cov,type='h',cex=0.1,cex.axis=2,cex.lab=2,cex.main=3,col=res$col,xaxt='n',main=title,xlab='chromosome',ylab='coverage',frame.plot=F,ylim=c(0,ymax))
    xticks = numeric(nrow(genome))
    for (i in 1:nrow(genome)){
       xticks[i] = (offset[i]+offset[i+1])/2*res$nbin/offset[length(offset)]
    }
    mtext(genome[,1],side=1,at=xticks,adj=1,las=2,col=seq(nrow(genome)))
}

union_correlation = function(x,y){
	z = x>0 | y>0
	cor(x[z],y[z])
}


heatmap2 = function(x,scale,sym,margins,labRow,labCol){
    h = heatmap(x,scale=scale,sym=sym,margins=margins,labRow=labRow,labCol=labCol)
    x = x[h$rowInd,h$colInd]
    tx = numeric(0)
    ty = numeric(0)
    txt = character(0)
    for (i in 1:nrow(x)){
        for (j in 1:ncol(x)){
            tx <- c(tx,i)
            ty <- c(ty,ncol(x)-j+1)
            txt <- c(txt,format(x[i,j],digits=2,nsmall=2))
        }    
    }
    #heatmap(x,scale=scale,sym=sym,margins=margins,labRow=labRow[h$rowInd],labCol=labCol[h$colInd],add.expr=text(1:4,1:4,1:4))
	cat(dim(tx))
	text(tx,ty,txt)
	heatmap(x,scale=scale,sym=sym,margins=margins,labRow=labRow[h$rowInd],labCol=labCol[h$colInd],add.expr=text(tx,ty,txt))

}