“doc” (Col. : Science Sup 17x24) — 2007/7/19 — 18:18 — page 116 — #126
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• Techniques de programmation déclarative
local
fun {Improve Guess X}
(Guess + X/Guess) / 2.0
end
fun {GoodEnough Guess X}
{Abs X-Guess * Guess}/X < 0.00001
end
fun {SqrtIter Guess X}
if {GoodEnough Guess X} then Guess
else {SqrtIter {Improve Guess X} X} end
end
in
fun {Sqrt X}
Guess=1.0 in
{SqrtIter Guess X}
end
end
Figure 3.5 Trouver les racines avec la méthode de Newton (deuxième version).
fun {Sqrt X}
fun {SqrtIter Guess X}
fun {Improve Guess X}
(Guess + X/Guess) / 2.0
end
fun {GoodEnough Guess X}
{Abs X-Guess * Guess}/X < 0.00001
end
in
if {GoodEnough Guess X} then Guess
else {SqrtIter {Improve Guess X} X} end
end
Guess=1.0
in {SqrtIter Guess X} end
Figure 3.6 Trouver les racines avec la méthode de Newton (troisième version).