15 lines
376 B
Python
15 lines
376 B
Python
import math
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def mean_std(xs):
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"""Return (mean, population standard deviation) of list xs."""
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n = len(xs)
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if n == 0:
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raise ValueError("Empty list")
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mean = sum(xs) / n
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var = sum((x - mean) ** 2 for x in xs) / n # population variance
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std = math.sqrt(var)
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return (mean, std)
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if __name__ == "__main__":
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print(mean_std([2,4,4,4,5,5,7,9]))
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