Generate a Stochastic Enrollment and Dropout Schedule
stochastic_schedule.RdCreates a time-indexed schedule of enrollment and dropout events across arms by sampling inter-event times from user-supplied distribution functions. Each call produces a different realization, capturing natural variability in study timelines.
Value
data.frame with columns: time, arm, enroll (always 1),
drop (always 0 or 1). One row per subject event, sorted by time.
Details
Use this when trial-duration variability is substantively important.
For a fixed, reproducible schedule see deterministic_schedule().
See also
deterministic_schedule() for piecewise-constant rates,
add_timepoints() to attach to a Timer.
Examples
stochastic_schedule(
sample_size = 100,
arms = c("A", "B"),
allocation = c(2, 1),
enrollment = function(n) rexp(n, rate = 0.5),
dropout = function(n) rexp(n, rate = 0.1)
)
#> time arm enroll drop
#> 1 1.456704 A 1 0
#> 2 2.734573 A 1 0
#> 3 9.093571 A 0 1
#> 4 10.299181 A 0 1
#> 5 11.691932 B 1 0
#> 6 15.719194 A 1 0
#> 7 23.052998 A 1 0
#> 8 24.704354 B 1 0
#> 9 25.456462 A 1 0
#> 10 26.632057 B 0 1
#> 11 26.936810 B 0 1
#> 12 27.361450 A 0 1
#> 13 28.907542 A 1 0
#> 14 31.554882 A 1 0
#> 15 37.032535 A 1 0
#> 16 38.663351 B 1 0
#> 17 40.690759 A 0 1
#> 18 40.941375 A 1 0
#> 19 42.401628 A 1 0
#> 20 43.956041 B 1 0
#> 21 50.508814 B 1 0
#> 22 50.738620 A 0 1
#> 23 51.997479 A 1 0
#> 24 52.659881 A 1 0
#> 25 53.203848 A 0 1
#> 26 53.330442 A 1 0
#> 27 60.038217 A 1 0
#> 28 60.818638 B 1 0
#> 29 63.111025 A 1 0
#> 30 63.304002 A 1 0
#> 31 65.050371 A 1 0
#> 32 67.840284 A 1 0
#> 33 68.199891 A 1 0
#> 34 68.265026 B 0 1
#> 35 68.446593 A 1 0
#> 36 69.201478 B 1 0
#> 37 71.077938 A 1 0
#> 38 71.500286 A 1 0
#> 39 71.605446 A 1 0
#> 40 72.065417 A 0 1
#> 41 77.621347 A 1 0
#> 42 87.428161 B 1 0
#> 43 88.515799 B 1 0
#> 44 90.826067 A 1 0
#> 45 91.114362 A 1 0
#> 46 91.929614 B 1 0
#> 47 92.558498 B 1 0
#> 48 94.259609 A 1 0
#> 49 96.175637 A 0 1
#> 50 99.530155 A 1 0
#> 51 100.379570 A 1 0
#> 52 101.815015 B 0 1
#> 53 104.902711 A 1 0
#> 54 104.915437 B 1 0
#> 55 107.768739 B 1 0
#> 56 109.764899 B 1 0
#> 57 110.670494 A 1 0
#> 58 111.274985 B 1 0
#> 59 111.379158 A 1 0
#> 60 111.437882 A 1 0
#> 61 112.027651 A 1 0
#> 62 113.789375 A 1 0
#> 63 117.078688 A 1 0
#> 64 121.941369 A 1 0
#> 65 124.964297 B 1 0
#> 66 128.453191 B 1 0
#> 67 129.501132 A 1 0
#> 68 129.610712 A 1 0
#> 69 129.628790 A 1 0
#> 70 130.401586 A 1 0
#> 71 130.550328 A 1 0
#> 72 130.756323 B 1 0
#> 73 131.737690 A 1 0
#> 74 132.150422 B 1 0
#> 75 133.612130 B 1 0
#> 76 134.269398 A 0 1
#> 77 137.168882 A 1 0
#> 78 137.847296 A 1 0
#> 79 138.033387 B 1 0
#> 80 139.279242 B 1 0
#> 81 140.315909 A 1 0
#> 82 140.666292 A 0 1
#> 83 147.816144 A 1 0
#> 84 148.374101 A 0 1
#> 85 150.249668 A 1 0
#> 86 156.619590 A 0 1
#> 87 157.051173 A 1 0
#> 88 158.242785 B 1 0
#> 89 158.994986 A 1 0
#> 90 159.329237 A 1 0
#> 91 159.484021 A 0 1
#> 92 159.532530 B 0 1
#> 93 160.002532 A 1 0
#> 94 160.047790 A 1 0
#> 95 161.098793 B 1 0
#> 96 161.197818 A 1 0
#> 97 172.360536 A 1 0
#> 98 173.097226 A 1 0
#> 99 173.225831 A 0 1
#> 100 175.555013 A 1 0
#> 101 177.497733 B 1 0
#> 102 178.731278 B 1 0
#> 103 184.959304 B 1 0
#> 104 185.090380 A 0 1
#> 105 187.255540 A 1 0
#> 106 187.632594 B 0 1
#> 107 188.204440 A 1 0
#> 108 188.588156 A 0 1
#> 109 190.374854 B 1 0
#> 110 190.593582 B 1 0
#> 111 193.562068 A 1 0
#> 112 194.701794 B 1 0
#> 113 194.984731 B 1 0
#> 114 195.370183 A 1 0
#> 115 195.590172 A 1 0
#> 116 195.623012 A 1 0
#> 117 196.162516 A 1 0
#> 118 201.295025 B 1 0
#> 119 204.656562 A 1 0
#> 120 204.711489 B 0 1
#> 121 207.286188 A 1 0
#> 122 209.406998 A 1 0
#> 123 212.115352 B 1 0
#> 124 223.879408 A 0 1
#> 125 231.415438 B 0 1
#> 126 232.858411 A 0 1
#> 127 245.796650 A 0 1
#> 128 247.105958 B 0 1
#> 129 253.698436 A 0 1
#> 130 256.540712 B 0 1
#> 131 269.132134 A 0 1
#> 132 273.323731 A 0 1
#> 133 296.014755 A 0 1
#> 134 312.692483 A 0 1
#> 135 316.004942 B 0 1
#> 136 321.478785 A 0 1
#> 137 330.226260 B 0 1
#> 138 351.521173 A 0 1
#> 139 360.815822 A 0 1
#> 140 379.489991 B 0 1
#> 141 379.629946 A 0 1
#> 142 416.569564 A 0 1
#> 143 422.043285 A 0 1
#> 144 423.236587 B 0 1
#> 145 426.065839 A 0 1
#> 146 434.932743 A 0 1
#> 147 440.787510 B 0 1
#> 148 442.498821 A 0 1
#> 149 455.220653 A 0 1
#> 150 461.445400 B 0 1
#> 151 471.119395 B 0 1
#> 152 472.748342 B 0 1
#> 153 481.543017 A 0 1
#> 154 498.508281 A 0 1
#> 155 512.794275 A 0 1
#> 156 515.228795 A 0 1
#> 157 516.188681 B 0 1
#> 158 531.991161 B 0 1
#> 159 533.182079 A 0 1
#> 160 543.216979 A 0 1
#> 161 547.608725 A 0 1
#> 162 556.220781 B 0 1
#> 163 579.152930 A 0 1
#> 164 591.736205 A 0 1
#> 165 640.103553 A 0 1
#> 166 645.016964 B 0 1
#> 167 651.551274 A 0 1
#> 168 655.290184 B 0 1
#> 169 663.279251 A 0 1
#> 170 666.463210 B 0 1
#> 171 682.324262 A 0 1
#> 172 700.030649 A 0 1
#> 173 709.214571 A 0 1
#> 174 720.942334 B 0 1
#> 175 744.172198 A 0 1
#> 176 748.435202 B 0 1
#> 177 749.453656 A 0 1
#> 178 764.185832 B 0 1
#> 179 768.081064 A 0 1
#> 180 772.518235 A 0 1
#> 181 775.096790 A 0 1
#> 182 782.884622 A 0 1
#> 183 820.005666 A 0 1
#> 184 832.630388 A 0 1
#> 185 850.248279 A 0 1
#> 186 859.965435 A 0 1
#> 187 873.439110 A 0 1
#> 188 878.625823 A 0 1
#> 189 886.432903 A 0 1
#> 190 907.430665 B 0 1
#> 191 914.909762 B 0 1
#> 192 936.601223 B 0 1
#> 193 941.743194 A 0 1
#> 194 943.128877 A 0 1
#> 195 949.147234 A 0 1
#> 196 953.702488 A 0 1
#> 197 972.724100 A 0 1
#> 198 973.312215 A 0 1
#> 199 975.284986 B 0 1
#> 200 979.863447 A 0 1