As a new user, I would like to learn how can calculate "skill scores" between observed and model data by R software.
My data is in an excel sheet which is attached to the following link.

Here, pmin() compares pairwise values from your two columns and takes the minimum. sum() just sums them up, which results in \sum_{i = 1}^{n} \min\{{Z_{i,m}, Z_{i,o}}\}