Re: Hex floating point format specifier?

Not a s/printf specifier but, for pre-5.22, there's Data::Float's float_hex() function:

C:\>perl -MData::Float="float_hex" -le "print float_hex(1 / 9);"
+0x1.c71c71c71c71cp-4
[download]

Cheers,
Rob

Comment on Re: Hex floating point format specifier? Download Code

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Re^2: Hex floating point format specifier? by BrowserUk (Patriarch) on Jun 18, 2015 at 10:47 UTC
Thanks for that. I won't be using it directly as I don't need its flexibility and I'll need to extend it for my extended precision numbers; but it made a nice reference. This is my version for standard doubles: `sub fmt{ my $bin = unpack 'Q', pack 'd', $_[0]; my $sign = ( $bin & 0x8000000000000000 ); my $exp = ( $bin & 0x7FF0000000000000 ) >> 52; $exp -= 1023; my $mant = ( $bin & 0x000FFFFFFFFFFFFF ); sprintf "%s0x1.%xp%d", ( $sign ? '-' : '' ), $mant, $exp; }` [download] Some outputs: `C:\test>fmt -- -1/9 -0x1.c71c71c71c71cp-4 C:\test>fmt -- 1/9 0x1.c71c71c71c71cp-4 C:\test>fmt -- 1/3 0x1.5555555555555p-2 C:\test>fmt -- 1/11 0x1.745d1745d1746p-4 C:\test>fmt -- "( 1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64 + 1/128 + 1/256 + + 1/512 + 1/1024 + 1/2048 + 1/4096 + 1/8192 + 1/16384 + 1/32768 + 1/ +65536 + 1/131072 + 1/262144 + 1/524288 )" 0x1.ffffc00000000p-1` [download] With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". I'm with torvalds on this In the absence of evidence, opinion is indistinguishable from prejudice. Agile (and TDD) debunked	[reply] [d/l] [select]

Replies are listed 'Best First'.

Re^2: Hex floating point format specifier?
by BrowserUk (Patriarch) on Jun 18, 2015 at 10:47 UTC

Thanks for that. I won't be using it directly as I don't need its flexibility and I'll need to extend it for my extended precision numbers; but it made a nice reference.

This is my version for standard doubles:

sub fmt{
    my $bin = unpack 'Q', pack 'd', $_[0];
    my $sign = ( $bin & 0x8000000000000000 );
    my $exp  = ( $bin & 0x7FF0000000000000 ) >> 52; $exp -= 1023;
    my $mant = ( $bin & 0x000FFFFFFFFFFFFF );
    sprintf "%s0x1.%xp%d", ( $sign ? '-' : '' ), $mant, $exp;
}
[download]

Some outputs:

C:\test>fmt -- -1/9
-0x1.c71c71c71c71cp-4

C:\test>fmt -- 1/9
0x1.c71c71c71c71cp-4

C:\test>fmt -- 1/3
0x1.5555555555555p-2

C:\test>fmt -- 1/11
0x1.745d1745d1746p-4

C:\test>fmt -- "( 1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64 + 1/128 + 1/256
+ + 1/512 + 1/1024 + 1/2048 + 1/4096 + 1/8192 + 1/16384 + 1/32768 + 1/
+65536 + 1/131072 + 1/262144 + 1/524288 )"
0x1.ffffc00000000p-1
[download]

With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

"Science is about questioning the status quo. Questioning authority". I'm with torvalds on this

In the absence of evidence, opinion is indistinguishable from prejudice. Agile (and TDD) debunked

[reply]
[d/l]
[select]