Fig.1

The power functions of GPV-based method (GP), Delta (Delta method) and Empirical bootstrap method (EB). Panel (A) represents the power functions when \(\mu_{R} - \mu_{P} = 9\) and \(n = 60\); Panel (B) represents the power functions when \(\mu_{R} - \mu_{P} = 9\) and \(n = 120\); Panel (C) represents the power functions when \(\mu_{R} - \mu_{P} = 9\) and \(n = 480\);Panel (D) represents the power functions when \(\mu_{R} - \mu_{P} = 20\) and \(n = 60\); Panel (E) represents the power functions when \(\mu_{R} - \mu_{P} = 20\) and \(n = 120\); Panel (F) represents the power functions when \(\mu_{R} - \mu_{P} = 20\) and \(n = 480\). The significance level of the non-inferiority test is set to be 0.05