---
title: "Simulation-Based Sample Size with Delayed Onset"
output: rmarkdown::html_vignette
vignette: >
  %\VignetteIndexEntry{Sample Size Simulation}
  %\VignetteEngine{knitr::rmarkdown}
  %\VignetteEncoding{UTF-8}
---

```{r, include = FALSE}
knitr::opts_chunk$set(collapse = TRUE, comment = "#>")
```

```{r setup}
library(progme)
```

Ignoring a 6-month delayed onset inflates the apparent treatment effect
and underestimates the required sample size. `power_pmrm()` simulates
the full operating characteristic:

```{r}
p <- power_pmrm(n_per_arm = 100, effect_size = -0.5, delay = 6,
                n_sims = 50, seed = 1)
p[c("power", "bias", "non_convergence_rate")]
```

Search a grid of sample sizes (keep simulations small for the demo):

```{r}
ss <- find_sample_size(target_power = 0.8, n_grid = c(80, 120),
                       effect_size = -0.5, delay = 6,
                       n_sims = 30, seed = 2)
ss$power_curve
```