**50**wrote:

Hi guys,

I've got this kind of matrix : https://ibb.co/r47yY3m

I would like to compute correlations between each pair of OTUs according to this formula (rho coefficient):

(for example between the first and second OTU)

```
1-((var(lol[1,]-lol[2,]))/(var(lol[1,])+var(lol[2,])))
```

How could I create a function to compute automatically each correlation between each pair according to get a result like this :

```
OTU0001 OTU0004 X
OTU0001 OTU0014 X
....
OTU0016 OTU0017 X
```

Thanks