From: Mikael Magnusson <mikachu@gmail.com>
To: zsh-workers@zsh.org
Subject: Re: zsh converts a floating-point number to string with too much precision
Date: Fri, 20 Dec 2019 04:38:16 +0100 [thread overview]
Message-ID: <CAHYJk3Sz6WWDwe92_sQM9By-Eus-=CqdvAfYcYhPiPAgo2batQ@mail.gmail.com> (raw)
In-Reply-To: <20191220013711.GA708801@zira.vinc17.org>
On 12/20/19, Vincent Lefevre <vincent@vinc17.net> wrote:
> With zsh 5.7.1, I get:
>
> zira% echo $((1.1))
> 1.1000000000000001
>
> because zsh seems to first select the precision independently
> from the value, i.e. 17 to be able to convert the string back
> to floating point, preserving the original value, then it
> outputs the closest number in this precision.
>
> Instead, zsh should select the minimum precision so that the
> inverse conversion can give the original value, i.e. it should
> output 1.1 here.
You can use typeset -F1 one=1.1 to specify the output precision of a
parameter (note that this doesn't affect the float value stored, you
can change to -F20 later to display more decimals without
reassignment). So in your case you could count the number of digits in
the string after the . and then pass that to -F if you wanted to.
--
Mikael Magnusson
next prev parent reply other threads:[~2019-12-20 3:39 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-20 1:37 Vincent Lefevre
2019-12-20 3:38 ` Mikael Magnusson [this message]
2019-12-20 16:58 ` Stephane Chazelas
2019-12-20 17:12 ` Roman Perepelitsa
2019-12-21 0:50 ` Vincent Lefevre
2019-12-21 8:47 ` Stephane Chazelas
2019-12-21 9:43 ` Roman Perepelitsa
2019-12-21 17:56 ` Stephane Chazelas
2019-12-21 18:11 ` Stephane Chazelas
2019-12-21 18:20 ` Roman Perepelitsa
2019-12-21 21:28 ` Vincent Lefevre
2019-12-21 1:00 ` Vincent Lefevre
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