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c6f8f3882a
* chore: add balls and bins simulator Signed-off-by: Roman Gershman <roman@dragonflydb.io> * Update balls_bins.py Signed-off-by: Roman Gershman <roman@dragonflydb.io> --------- Signed-off-by: Roman Gershman <roman@dragonflydb.io>
72 lines
2.3 KiB
Python
Executable file
72 lines
2.3 KiB
Python
Executable file
#!/usr/bin/env python3
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"""Simulate throwing balls into bins."""
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import numpy as np
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import argparse
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import matplotlib.pyplot as plt
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def simulate_balls_into_bins(balls: int, bins: int, threshold: int, exact, trials=10000):
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"""Simulate throwing M balls into N bins for a given number of trials."""
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counts = np.zeros(bins, dtype=int)
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success = 0
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exact_success = 0
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deltas = []
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for _ in range(trials):
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# Reset counts for each trial
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counts.fill(0)
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# Throw M balls into the bins
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bins_seq = np.random.randint(0, bins, balls)
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unique, counts_bins = np.unique(bins_seq, return_counts=True)
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counts[unique] += counts_bins
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deltas.append(counts.max() - counts.min())
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# Check if any bin has K or more balls
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if np.any(counts >= threshold):
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success += 1
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if exact is not None:
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if np.any(counts == exact):
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exact_success += 1
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probability = success / trials
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return deltas, probability, exact_success / trials
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def main():
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parser = argparse.ArgumentParser(description="Simulate throwing balls into bins.")
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parser.add_argument("--balls", type=int, default=30, help="Number of balls to throw.")
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parser.add_argument("--bins", type=int, default=3, help="Number of bins.")
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parser.add_argument(
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"--high-threshold",
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type=int,
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default=15,
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help="Minimum number of balls for the success condition",
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)
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parser.add_argument(
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"--exact-num", type=int, help="Exact number of balls for the success condition."
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)
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parser.add_argument(
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"--trials", type=int, default=10000, help="Number of trials. Default is 10,000."
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)
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args = parser.parse_args()
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deltas, atleast_p, exact_p = simulate_balls_into_bins(
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args.balls, args.bins, args.high_threshold, args.exact_num, args.trials
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)
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print(f"Probability that at least one bin has {args.high_threshold} or more balls: {atleast_p}")
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if args.exact_num is not None:
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print(f"Probability that at least one bin has {args.exact_num} balls: {exact_p}")
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print(
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f"Histogram of the difference between the most and least populated bins for {args.trials} trials"
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)
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plt.hist(deltas, bins=30, color="steelblue", edgecolor="none")
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plt.show()
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if __name__ == "__main__":
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main()
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