27 lines
607 B
Plaintext
27 lines
607 B
Plaintext
(defn square [x] (* x x))
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(defn good-enough? [previous current]
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(>=
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(* current 0.0001)
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(math/abs (- current previous))))
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(defn improve [guess x]
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(/
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(+ (* 2 guess) (/ x (square guess)))
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3))
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(defn cbrt-iter [prev guess x]
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(if (good-enough? prev guess)
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guess
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(cbrt-iter guess (improve guess x) x)))
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(defn cube-root [x]
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(cbrt-iter 0.0 x x))
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(var i 0.0000001)
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(while (<= i 1000000000000.0)
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(def meas (cube-root i))
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(def rel (/ (- meas (math/cbrt i)) meas))
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(print (string/format "Relative error %f=%f, %f" (math/cbrt i) meas rel))
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(set i (* i 3.141519)))
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