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Diffstat (limited to 'Doc/library/random.rst')
| -rw-r--r-- | Doc/library/random.rst | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/Doc/library/random.rst b/Doc/library/random.rst index 4d0c8bc..b0f8194 100644 --- a/Doc/library/random.rst +++ b/Doc/library/random.rst @@ -426,25 +426,32 @@ between the effects of a drug versus a placebo:: Simulation of arrival times and service deliveries in a single server queue:: - from random import gauss, expovariate + from random import expovariate, gauss + from statistics import mean, median, stdev average_arrival_interval = 5.6 average_service_time = 5.0 stdev_service_time = 0.5 num_waiting = 0 + arrivals = [] + starts = [] arrival = service_end = 0.0 for i in range(20000): if arrival <= service_end: num_waiting += 1 arrival += expovariate(1.0 / average_arrival_interval) - print(f'{arrival:6.1f} arrived') + arrivals.append(arrival) else: num_waiting -= 1 service_start = service_end if num_waiting else arrival service_time = gauss(average_service_time, stdev_service_time) service_end = service_start + service_time - print(f'\t\t{service_start:.1f} to {service_end:.1f} serviced') + starts.append(service_start) + + waits = [start - arrival for arrival, start in zip(arrivals, starts)] + print(f'Mean wait: {mean(waits):.1f}. Stdev wait: {stdev(waits):.1f}.') + print(f'Median wait: {median(waits):.1f}. Max wait: {max(waits):.1f}.') .. seealso:: |