data.table::setDTthreads(2)
data(product_test)
cross_cpct(product_test, mrset(a1_1 %to% a1_6))
# same result
cross_cpct(product_test, mrset_f(a1_))
# same result
cross_cpct(product_test, mrset_p("a1_"))
# same result
cross_cpct(product_test, mrset_t("a1_{1:6}"))
Run the code above in your browser using DataLab