>>>>> "Stavros" == Stavros Macrakis <stavros.macrakis@verizon.net> writes:
[I'm sending this maxima list and to your verizon address since your
mit address is bouncing my mail.]
Stavros> fpprec:25;
Stavros> cf(1.0b-25) => [0, 10000000000000000000000000]
>>
>>
>> Interesting. What system is this on? I tried both examples on a Sun
>> box with CMUCL, Clisp, and ACL6 and I get the second answer above.
Stavros> What is the default fpprec on those systems?
16, as expected.
Stavros> What do you get for the following:
Stavros> fpprec:16;
Stavros> fix(1.0b25);
9999999999999999832227840
Stavros> fpprec:25;
Stavros> fix(1.0b25);
10000000000000000000000000
Stavros> 1.0b0+1.0b-22-1.0b0;
Stavros> => 1.000113059364895023149213B-22
Stavros> 1.000113059364895023149213B-22
>>
>> Perhaps this is the explanation. I get 9.998545654234722020008153B-23
>> as the answer.
Stavros> I still don't understand this one. What is ?fpprec ?
fpprec is 25, as you set it.
Note that 1.0b-22 is
((BIGFLOAT SIMP 86) 73075081866545145910184242 -73)
and that 1.0b0+1.0b-22-1.0b0 is
((BIGFLOAT SIMP 86) 73064454222959150746304512 -73)
which seems reasonable.
Ray