# Consensus peaks

A consensus peak is created on a position of genome where is covered by at least one peak from the `output`

sets of the processed replicates. Accordingly, a consensus peak has the following characteristics:

**Coordinate**(i.e.,*chromosome*,*start*, and*stop*)

The**coordinate**of a consensus peak is the union of the coordinates of the peaks from`output`

sets which overlap that position on the genome. For instance:`// From the Output set of Replicate 1`

chr1 10 20 macs_peak_1 20.9

// From the Output set of Replicate 2

chr1 15 25 macs_peak_1 14.6

// The resulting consensus peak

chr1 10 25 mspc_peak_1 163.484

Note that the p-values are in `-log10` format.**Value**

The value of each consensus peak is`X^2`

which is calculated by combining the`p-value`

s of the overlapping peaks using Fisher's combined probability test:`X_i^2 = -2 \times \sum_{i=1}^k \ln(p_i)`

where `X_i^2`

is the value of consensus peak `i`

, and `p_i`

is the p-value of overlapping peaks. For instance, the `X^2`

of aforementioned consensus peaks is `163.484`

, which is calculated by combining the p-values of overlapping peaks (i.e., `20.9`

and `14.6`

) using the Fisher's method.