Just integrate data according to fixed rt and fixed noise area
file should be a dataframe with the first column RT and second column intensity of the SIM ions.
a rough RT range contained only one peak to get the area
a rough RT range contained only one peak and enough noises to get the area
logical, if using an average smooth box or not. If using, n will be used
area integration data
if (FALSE) {
area <- Integration(data)
}