function(DM, volume)
{
	vDM <- matrix(0, nrow(DM), ncol(DM))
	for(i in 1:nrow(DM))
		for(j in 20:ncol(DM))
			if(DM[i, j] == 1) {
				t1 <- mean(volume[(j - 20):(j - 10)])
				t2 <- mean(volume[(j - 10):j])
				if(t1 > 1.2 * t2)
				  vDM[i, j] <- -1
				else if(t2 > 1.2 * t1)
				  vDM[i, j] <- 1
			}
	return(vDM)
}
