runlength_dict.Rmd

# Run Length Encoding dicts

Since you need more than one run length to describe a genome with multiple
chromosomes, pyranges has a datastructure called PyRles for collections of Rles.
It can be created from a PyRanges object by invoking the coverage function.

Rledicts support the arithmetic operations +, -, /, and *.

```{python tidy=FALSE}
import pyranges as pr

gr = pr.load_dataset("chipseq")
gr_bg = pr.load_dataset("chipseq_background")

cs = gr.coverage()
print(cs)

bg = gr_bg.coverage()
print(bg)

print(cs + bg)
```

When using arithmetic operations with a stranded and an unstranded PyRle, the
stranded PyRle is automatically demoted to an unstranded PyRle.

```{python tidy=FALSE}


bg_stranded = gr_bg.coverage(stranded=True)
print(bg_stranded)

print(cs + bg_stranded)
```

Like Rles, PyGRles supports arithmetic operations with numbers.

```{python tidy=FALSE}

print((0.67 + cs) * 5)
```