15 lines
435 B
Racket
15 lines
435 B
Racket
#lang racket
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(define (mean l)
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(/ (apply + l) (length l)))
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(define (diversity-theorem truth predictions)
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(define μ (mean predictions))
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(define (avg-sq-diff a)
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(mean (map (λ (p) (sqr (- p a))) predictions)))
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(hash 'average-error (avg-sq-diff truth)
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'crowd-error (sqr (- truth μ))
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'diversity (avg-sq-diff μ)))
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(println (diversity-theorem 49 '(48 47 51)))
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(println (diversity-theorem 49 '(48 47 51 42)))
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