extdata file descriptions:

* example.CAPRI: a mutational matrix in "CAPRI" format (1000 genes * 160 samples) used as an example

* example.CAPRIpop: a small mutational matrix in "CAPRIpop" format used as an example

* paac_jhu_2014_500.maf: 500 lines randomly sampled of a pubblicly available MAF file (Acinar Cell Carcinoma of the Pancreas (JHU, J Pathol 2014) [not single cell data, here used just as an example]). This file can be downloaded from cBioPortal Data Set section.

code:

```
$ head -1 data_mutations_extended.txt > header
$ tail -n +2 data_mutations_extended.txt | shuf -n 500 > content
$ cat header content > paac_jhu_2014_500.maf
```

