calc_chunks             Calculate data chunk indices
calc_duration           Calculate durations of time
chunk_data_             Break data into chunks
cusum_failure           Cumulative Sum of Failures
cusum_loglike           Cumulative Sum of Log-Likelihood Ratio
cusum_ome               Cumulative Sum of Observed Minus Expected
                        Outcome
cusum_sprt              Risk-adjusted Sequential Probability Ratio Test
                        (SPRT)
paste                   Concatenate strings
paste_efs               Paste event-free survival
paste_freq              Paste frequency
paste_mean              Paste mean
paste_median            Paste median
paste_pval              Paste p-value
test_hypothesis         Test the null hypothesis
