Re: Floating Point Approximations.
From: paul c <toledobythesea_at_oohay.ac>
Date: Thu, 29 Mar 2007 00:44:39 GMT
Message-ID: <XZDOh.84465$DN.30023_at_pd7urf2no>
>
>
> Nope: 0.5 millionths versus 0.0298 millionths scaled by the exponent
> part of the float.
>
> For floating point representations, epsilon is the rounding factor,
> which is half the least significant digit of the mantissa. If I recall
> correctly, a 32-bit BCD float has a 6 decimal digit mantissa with a 2
> decimal digit exponent. A 32-bit binary float has a 24 bit mantissa with
> an 8 bit exponent.
Date: Thu, 29 Mar 2007 00:44:39 GMT
Message-ID: <XZDOh.84465$DN.30023_at_pd7urf2no>
Bob Badour wrote:
> paul c wrote:
>
>> Bob Badour wrote: >> >>> ... >>> The epsilon would be 16 times larger for BCD floats. >>> ie. 5e-7 versus 2^-25 >> >> >> Sorry, not hip to epsilon in this context. Does the above correspond >> with 50 millionths versus 32 millionths, or thereabouts?
>
>
> Nope: 0.5 millionths versus 0.0298 millionths scaled by the exponent
> part of the float.
>
> For floating point representations, epsilon is the rounding factor,
> which is half the least significant digit of the mantissa. If I recall
> correctly, a 32-bit BCD float has a 6 decimal digit mantissa with a 2
> decimal digit exponent. A 32-bit binary float has a 24 bit mantissa with
> an 8 bit exponent.
Sorry, forgot to ask - I assume you're talking about IBM BCD mantissa?
thanks,
p
Received on Thu Mar 29 2007 - 02:44:39 CEST