# Covariate file

The **COV** file contains the covariate data in simple txt format.
Hereafter an example of 4 covariates for 4 samples.

```
id UNR1 UNR2 UNR3 UNR4
```

PC1 -0.02 0.14 0.16 -0.02

PC2 0.01 0.11 0.10 0.01

PC3 0.03 0.05 0.08 0.07

BIN 1 0 0 1

Herafter, some properties of this file:

- The file is
*TAB*delimited - First row gives the sample ID and each additional one corresponds to a single covariate
- First column gives the covariate ID and each additional one corresponds to a sample
- The file should have S+1 rows and C+1 columns where S and C are the numbers of samples and covariates, respectively.

Both quantitative and qualitative covariates are supported.
**Quantitative** covariates are assumed when only **numeric** values are provided.
**Qualitative** covariates are assumed when only **non-numeric** values are provided.
In practice, qualitative covariates with *F* factors are converted in *F-1* binary quantitative covariates.