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Re: Adding double-float values together

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Date Sat, 24 Aug 2013 09:22:18 -0500
From Robert Miles <milesrf@Usenet-News.net>
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Subject Re: Adding double-float values together
References <f172a947-71c3-406b-8481-b73c8dbd8421@googlegroups.com> <0.f80b72e5b5ab6c2b75ca.20130814182335BST.878v04jieg.fsf@bsb.me.uk> <f8fecc24-924e-4d12-b4d2-85c558ec3d2e@googlegroups.com> <0.c8a484d9ffb18646a39b.20130814192211BST.87zjski14c.fsf@bsb.me.uk> <15451527-0775-4d75-b3df-7ad2553549a2@googlegroups.com> <0.11eb06d3be0f6c23440c.20130815020527BST.87ob8zix0o.fsf@bsb.me.uk> <b8b9f322-f29c-4fef-961a-06e5d2e9cef8@googlegroups.com> <0.199e7f1d0bb64ce9a16e.20130815030401BST.87d2pfiub2.fsf@bsb.me.uk> <5adfe06a-6ddf-41a9-bfaf-49271b5e85b9@googlegroups.com> <0.593019630819eda7e2dd.20130815170222BST.87zjsjgcxe.fsf@bsb.me.uk> <6918786f-e5f4-4306-80dc-a6ca6518f14d@googlegroups.com> <0.496dbdcba00648308483.20130816124501BST.87ioz5272a.fsf@bsb.me.uk> <23ce3ae2-c11c-41a5-be47-bce7e3928480@googlegroups.com> <521347b8$0$15903$e4fe514c@news2.news.xs4all.nl> <kv0hgd$13v$1@dont-email.me>
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On 8/20/2013 2:53 PM, Julio Di Egidio wrote:
> "Jongware" <jongware@no-spam.plz> wrote in message 
> news:521347b8$0$15903$e4fe514c@news2.news.xs4all.nl...
>> On 20-Aug-13 10:55 AM, industrial_one@hotmail.com wrote:
> <snipped>
>
>>> Is there ever a case where it makes sense to use a float for an 
>>> integer?
>
> The size of the significand is 23 bits for single-precision (i.e. 
> 32-bit) floats and 53 bits for double-precision (i.e. 64-bit) floats: 
> when converting from an integer, the value gets rounded if it cannot 
> fit in the significand.
>
>> Maybe there is a chance that a number could overflow max integer 
>> value, for each of the single entries or for the total after 
>> addition. Using floats makes sure you can count up to 10^38, but at 
>> the cost of precision.
>
> It is very easy here to overflow a 32-bit integer, as that would be 
> just 2 GB.  But I don't see any point in using doubles either, 64-bit 
> integers would be ideal: simpler, much more performant, and, I'd 
> assume, virtually impossible to overflow.
>
> Julio
>
I've seen some programs over at PrimeGrid that would overflow them 
easily, when trying
to find prime number integers with at least a million digits.

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Thread

Adding double-float values together industrial_one@hotmail.com - 2013-08-14 09:40 -0700
  Re: Adding double-float values together Ben Bacarisse <ben.usenet@bsb.me.uk> - 2013-08-14 18:23 +0100
    Re: Adding double-float values together industrial_one@hotmail.com - 2013-08-14 10:35 -0700
      Re: Adding double-float values together Ben Bacarisse <ben.usenet@bsb.me.uk> - 2013-08-14 19:22 +0100
        Re: Adding double-float values together industrial_one@hotmail.com - 2013-08-14 12:20 -0700
          Re: Adding double-float values together Ben Bacarisse <ben.usenet@bsb.me.uk> - 2013-08-15 02:05 +0100
            Re: Adding double-float values together Ben Bacarisse <ben.usenet@bsb.me.uk> - 2013-08-15 02:36 +0100
            Re: Adding double-float values together industrial_one@hotmail.com - 2013-08-14 18:42 -0700
              Re: Adding double-float values together Ben Bacarisse <ben.usenet@bsb.me.uk> - 2013-08-15 03:04 +0100
                Re: Adding double-float values together industrial_one@hotmail.com - 2013-08-14 21:17 -0700
                Re: Adding double-float values together Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2013-08-15 08:39 -0700
                Re: Adding double-float values together Ben Bacarisse <ben.usenet@bsb.me.uk> - 2013-08-15 17:02 +0100
                Re: Adding double-float values together industrial_one@hotmail.com - 2013-08-16 02:25 -0700
                Re: Adding double-float values together Ben Bacarisse <ben.usenet@bsb.me.uk> - 2013-08-16 12:45 +0100
                Re: Adding double-float values together industrial_one@hotmail.com - 2013-08-20 01:55 -0700
                Re: Adding double-float values together Jongware <jongware@no-spam.plz> - 2013-08-20 12:40 +0200
                Re: Adding double-float values together "Julio Di Egidio" <julio@diegidio.name> - 2013-08-20 20:53 +0100
                Re: Adding double-float values together Robert Miles <milesrf@Usenet-News.net> - 2013-08-24 09:22 -0500
                Re: Adding double-float values together "Julio Di Egidio" <julio@diegidio.name> - 2013-08-24 15:49 +0100

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