series[j]->n_index = max_cat + 1;
series[j]->index_to_category = xcalloc (
max_cat + 1, sizeof *series[j]->index_to_category);
series[j]->n_index = max_cat + 1;
series[j]->index_to_category = xcalloc (
max_cat + 1, sizeof *series[j]->index_to_category);