From: KFL@MIT-MC.ARPA ("Keith F. Lynch")
Subject: floating point number radix
Date: Sat, 19-Oct-85 13:50:37 EDT [thread overview]
Date: Sat Oct 19 13:50:37 1985
Message-ID: <[MIT-MC.ARPA].685203.851019.KFL> (raw)
Date: Fri 18 Oct 85 19:39:57-PDT
From: Doug Bryan <BRYAN@SU-SIERRA.ARPA>
[3.5.7(6)]
The reference manual states that the minimum number of binary digits, B,
required after the point in the binary mantissa of a floating point
number is...
ceiling (D * ln(10)/ln(2) + 1.0)
where D is the minimal number of decimal digits in the decimal mantissa.
Consider D = 3...
ceiling (3 * ln(10)/ln(2) + 1.0) = ceiling (10.9657) = 11
But... is not 10 binary digits sufficient to represent 3 decimal digits?
2**(-10) < 10**(-3)
We think the "+ 1.0" in the above expression can be removed.
Consider D=2. 2**(-6) > 10**(-2). The "+ 1.0" should stay.
...Keith
next reply other threads:[~1985-10-19 17:50 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
1985-10-19 17:50 "Keith F. Lynch" [this message]
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1985-10-19 2:39 floating point number radix Doug Bryan
1985-10-19 2:39 Doug Bryan
1985-10-20 20:17 ` dik
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