The peak shape filter is then applied to the experimental data and a score is
calculated at each genomic position.
The score is obtained by extracting the genomic coverage profile of a window
centered at the genomic position and then comparing this profile to the
peak shape filter.
The result of this comparison is defined as peak shape score. The peak shape score is
standardized and follows a standard normal distribution, so a p-value for
each genomic position can be calculated as
, where is the standard normal
cumulative distribution function.
Applying peak shape filters to call peaks
Once the peak shape score for the complete genome is calculated, peaks are identified
as genomic regions where the maximum peak shape score is greater than a given threshold.
The center of the peak is then identified as the genomic region with the highest
peak shape score and the boundaries are determined by the genomic positions
where the peak shape score becomes negative.