Truncating Floats

[Keith Fahlgren]

Hi,

I need to truncate some Floats and found this:
http://www.approximity.com/cgi-bin/blogtariAgile/index.rb/+Forth/RetroWeb.rdoc

It suggests:
class Float
def truncate(sd=2)
scale=(10**sd).to_f
(self * scale).to_i / scale
end
end
a=0.255
a.truncate(2) #-> 0.25


Is there a better way to do the above? I'm sort of surprised that there
isn't a builtin, but perhaps I'm not looking in the right place.



Thanks,
Keith

 

[gga]

Probably cause you can do it in one line:

('%.2f' % 0.255).to_f

 

[Kero]

Probably cause you can do it in one line:

('%.2f' % 0.255).to_f

That's rounding, not truncating.

For some purposes, there's BigDecimal, where x.yz is really two decimals
(and not an approximation as a flost takes)

And behold! BigDecimal#floor takes an argument, the number of digits you
want (had to look that up myself; learn something new every day

+--- Kero ------------------------- kero@chello@nl ---+
| all the meaningless and empty words I spoke |
| Promises -- The Cranberries |
+--- M38c --- http://members.chello.nl/k.vangelder ---+

 

[James Edward Gray II]

That's rounding, not truncating.

Okay, how about:

0.255.to_s.sub(/(\.\d{2})\d+/, "\\1").to_f

James Edward Gray II

 

[soxinbox]

for more enjoyment and greater efficiency:
(s=2.33333.to_s + "00").slice(0,s.index(".")+3)