Loading Read Counts

As you have seen in the video, you have to create a set of consensus peak calls before you can test for differential binding. This can be achieved with the following line of R code:

ar_counts <- dba.count(ar_peaks, summits=200)

Consider the following statements.

1. In ar_counts all samples will have read counts the same set of peak calls.
2. Some read counts may be 0.
3. All peaks in ar_counts are 200 bp wide.
4. All peaks in ar_counts are 400 bp wide.

Which of these statements are true?