Message-ID: <87pmboko3z.fsf@enricoschumann.net>
Date: 2023-01-09T10:18:24Z
From: Enrico Schumann
Subject: gmp::bigq vs. MASS::fractions
In-Reply-To: <6c8a775d-b141-edc0-c222-fbeea1d5cb95@wiwi.hu-berlin.de> (Sigbert Klinke's message of "Sat, 7 Jan 2023 17:29:35 +0100")
On Sat, 07 Jan 2023, Sigbert Klinke writes:
> Hi,
>
> has someone experience which routine should be used for
> creating fractional numbers? The two conversion
> routines deliver different results
>
>> x <- (0:7)/7
>
>> MASS::fractions(x)
>
> [1] 0 1/7 2/7 3/7 4/7 5/7 6/7 1
>
>> gmp::as.bigq(x)
>
> Big Rational ('bigq') object of length 8:
>
> [1] 0 2573485501354569/18014398509481984
> 2573485501354569/9007199254740992
>
> [4] 7720456504063707/18014398509481984
> 2573485501354569/4503599627370496
> 6433713753386423/9007199254740992
>
> [7] 7720456504063707/9007199254740992 1
>
> Following the example I would compute my fractional
> numbers with MASS::fractions and store them for further
> processing as Big Rational.
>
> Thanks Sigbert
>
'gmp' allows you to create the fractions directly:
gmp::as.bigq(n = 0:7, d = 7)
## Big Rational ('bigq') object of length 8:
## [1] 0 1/7 2/7 3/7 4/7 5/7 6/7 1
--
Enrico Schumann
Lucerne, Switzerland
http://enricoschumann.net