Compute year-over-year variation in skill rankings

Takes the output of compute_skill_ranking_series() and calculates ranking changes between consecutive time periods. The function pivots the series to wide format with rank and count columns per period, filters by a minimum count threshold, computes the rank variation (previous rank minus current rank, so positive values indicate improvement), and returns the top-k skills per profession.

Usage

compute_skill_variation(serie, min_n = 30L, top_k = 10L)

Arguments

serie

A data.table as returned by compute_skill_ranking_series(), with columns professione, mese, skill, N, and rango.

min_n

Integer, minimum count in the most recent period for a skill to be included in the variation analysis. Default: 30L.

top_k

Integer, number of top-ranked skills to return per profession (by most recent rank). Default: 10L.

Value

A data.table in wide format with one row per profession-skill pair. Columns include professione, skill, rank and count columns for each time period (named as rango_<period> and N_<period>), and variazione (rank change from previous to current period).