What is the easiest way to convert a hex value like:
0x000000000000F03F (big endian, IEEE754)
to a Float in Ruby?
Thanks,
Matt
On 3-May-06, at 6:44 PM, Matt Bauer wrote:
Posted via http://www.ruby-forum.com/.
Probably using pack and unpack, my first guess is something like
irb(main):001:0> [0x000000000000F03F].pack(‘Q’).unpack(‘G’)
=> [3.03865194161742e-319]
but now I have to look up IEEE and it looks reasonable:
irb(main):002:0> [0x0000000000000000].pack(‘Q’).unpack(‘G’)
=> [0.0]
irb(main):003:0> [0x8000000000000000].pack(‘Q’).unpack(‘G’)
=> [-0.0]
and using a sample single precision number in binary from http://
www.psc.edu/general/software/packages/ieee/ieee.html
0 10000001 10100000000000000000000 = +1 * 2**(129-127) * 1.101 = 6.5
irb(main):005:0> [0b01000000110100000000000000000000].pack(‘L’).unpack
(‘g’)
=> [6.5]
Hope this helps,
Mike
–
Mike S. [email protected]
http://www.stok.ca/~mike/
The “`Stok’ disclaimers” apply.