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Re: Function defined by a while loop

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From	Mauro <pippo@hotmail.com>
Newsgroups	comp.graphics.apps.gnuplot
Subject	Re: Function defined by a while loop
Date	Tue, 28 Jun 2011 11:56:13 +0200
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Il 27/06/2011 22:00, Hans-Bernhard Bröker ha scritto:
> On 27.06.2011 11:50, Antonio Lo Turco wrote:
>
>> Obviously I tried and it doesn't work!
>
> Of course it doesn't. while is a _command_, not an expression. You can't
> use it in the middle of an expression, like the one you use to define a
> function.
>
>> However I would like (and I'm not able) to implement such solution as
>> a user defined function.
>
> The only way there is recursion. But that will only work reasonably well
> for a _one_parameter_ loop. You loop over 'x' and 'i' simultaneously.
> That doesn't map cleanly to recursion over a single variable.
>
> Well, unless you make them the real and imaginary part of a complex
> number that is:
>
> iterate_f(x_i, x0, eps, maxiter) = \
> ((abs(real(x_i) - x0) < eps) || (imag(x_i) > maxiter)) \
> ? x_i \
> : iterate(f(real(x_i)) + (imag(x_i)+1)*{0,1}, x0, eps, maxiter)
>
> print iterate(x0,x0,eps,maxiter)

Thank you indeed!!!
Furthermore, it doesn't need while construct.
Nevertheless,I must congratulate all the Gnuplot development team for 
improving this unvaluable tool. The introduction of if, while and do for 
iterative constructs gives a further cut above to its practicality 
(maybe not for the functions ;-)).

Best regards

Mauro

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Thread

Function defined by a while loop Antonio Lo Turco <antonio.lo.turco@gmail.com> - 2011-06-27 02:50 -0700
  Re: Function defined by a while loop James Waldby <not@valid.invalid> - 2011-06-27 16:21 +0000
    Re: Function defined by a while loop Mauro <pippo@hotmail.com> - 2011-06-28 11:48 +0200
  Re: Function defined by a while loop Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2011-06-27 22:00 +0200
    Re: Function defined by a while loop Mauro <pippo@hotmail.com> - 2011-06-28 11:56 +0200

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