# 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:

1. The file is TAB delimited
2. First row gives the sample ID and each additional one corresponds to a single covariate
3. First column gives the covariate ID and each additional one corresponds to a sample
4. 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.