in reply to cos (100000000.0)

There's something related to Arbitrary-precision Arithmetic, I am not strong in Maths but from this query I got me curious and I found out that perl can allow you to use that sort of precision Arithmetic, please see, Arithmetic.

I know that negating 0 would give you the unsigned integer capacity of your machine, if this is got to do with addressing your problem, then I hope I have been able to contribute and I'd be happy, otherwise, I'd be happy as well if someone corrected me. 

printf "%e", ~0;

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Re^2: cos (100000000.0)
by ikegami (Patriarch) on Sep 02, 2009 at 00:07 UTC

    I know that negating 0 would give you the unsigned integer capacity of your machine, if this is got to do with addressing your problem,

    Both numbers fit into a double-precision float (the minimum size Perl uses for floats), so it's not a question of machine precision. It's a question of the precision/accuracy of the cos function.

    Note that the Config module provides information on the size of number types used internally. 

    $ perl -V:ivsize          4: -2**(4*8-1) .. 2**(4*8-1)-1
ivsize='4';               8: -2**(8*8-1) .. 2**(8*8-1)-1
                
$ perl -V:uvsize          4: 0 .. 2**(4*8)-1
uvsize='4';               8: 0 .. 2**(8*8)-1

$ perl -V:nvsize          8:  double, 53 bits of precision
nvsize='8';               16: quad,  113 bits of precision

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