Re: nth_root of num?

From: Claude Marche (Claude.Marche@lri.fr)
Date: Tue Dec 01 1998 - 11:35:39 MET


From: Claude Marche <Claude.Marche@lri.fr>
Date: Tue, 1 Dec 1998 11:35:39 +0100 (MET)
To: N Hur <mapnh@maths.bath.ac.uk>
Subject: Re: nth_root of num?
In-Reply-To: <Pine.SOL.4.05.9812011025090.6015-100000@odin.maths.bath.ac.uk>
        <Pine.SOL.4.05.9812011025090.6015-100000@odin.maths.bath.ac.uk>

>>>>> "N Hur" == N Hur <mapnh@maths.bath.ac.uk> writes:

    N Hur> Thank you.

    N Hur> But running your code for example,

    N Hur> root_floor 3 (Int 2) (* menaing third_root of 2 *);;
        
    N Hur> gives 1, while what we want is 1.2599210498 ...

Sorry, I misunderstood your question. I though you where interested in
computing the nth root of a big_num. If you are interested in
computing the nth root of a float, I really don't understand why you
are using big nums.

An algorithm for computing the nth root of a float is easy :

let nth_root n x = exp (log(x)/.(float_of_int n));;

Hope this helps. If it doesn't answer to your question, please explain
your problem more precisely.

- Claude

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