/prog/ - Christ. — World4ch

Name: Anonymous 2009-11-18 22:37

In Python, why the fuck does float(2/3) return 0.0?

Name: Anonymous 2009-11-18 22:41

That happens in *all* languages, integer division, /thread.

Name: Anonymous 2009-11-18 22:59

>>2
Not really.
I my Python (a Common Lisp compiler used by CMUCL, and from which SBCL is derived, which is what I'm using here):



CL-USER> 2/3

2/3

CL-USER> (* * 3)

2

CL-USER> (float 2/3)

0.6666667

CL-USER> (* * 3)

2.0

Name: Anonymous 2009-11-18 23:07

>>> float(2/3)
0.6666666666666666

Guess you're Python is just ancient. Try upgrading.

Name: Anonymous 2009-11-18 23:47

>>4
I'm using 2.6. If you're subtly telling me to go to 3000, you should eat your hat.

I just got around it by adding 0.0000 to each

Name: Anonymous 2009-11-18 23:49

Oh yeah, I forgot they changed this in Py3k. The old behaviour is 2//3.

Kinda stupid. Not sure how I feel about it.

Name: Anonymous 2009-11-18 23:56

Kinda fucking stupid that the language has been split up in a level of retardation only before seen in the D programming language.

Name: Anonymous 2009-11-19 0:23

>>1
Are you DEMENTED‽
Fuck you, OP. Fuck you.

Name: Anonymous 2009-11-19 0:45

Prelude> 2/3 :: Float

0.*** Exception: stack overflow

:(

Name: Anonymous 2009-11-19 1:14

$ echo "2/3" | bc ; echo "herpa derpa doooooo" ; echo "scale = 6 ; 2/3 " | bc
0
herpa derpa doooooo
.666666

Name: Anonymous 2009-11-19 10:21

>>7
How so?

The only thing that I can think of that you might be referring to is IHBT .

Name: Anonymous 2009-11-19 11:29

>>5
I just got around it by adding 0.0000 to each

It's a good thing you added '0.0000', and to each as well. If you were to add 0.000, or, God forbid, 0.00, not to speak about further unthinkable reductions, who knows what might have happened?! Worst of all, if you add things asymmetrically, never do this.

Name: Anonymous 2009-11-19 12:24

Use abs(2j / 3j), or if you've got a recent version, from __future__ import division

Name: Anonymous 2009-11-19 13:04

Prelude> map (logBase 2 . fact) [170, 171]

[1019.3694529277262, Infinity]

lol'd.

Name: Anonymous 2009-11-19 14:16

Christ, in python,lisp,C,java,pascal, why does 2/3 return 0?

Name: Anonymous 2009-11-19 14:19

>>12

I wasn't adding asymmetrically, and good lord you care a lot.

Name: Anonymous 2009-11-19 14:21

>>16
lisp
swing and a miss

Name: Anonymous 2009-11-19 14:48

>>15
<interactive>:1:38: Not in scope: type constructor or class `CReal'

Name: Anonymous 2009-11-19 15:37

>>20
I'm stupid. Anyway, it's not in the standard GHC installation.

Name: Anonymous 2009-11-19 16:34

~ % ghci

GHCi, version 6.10.4: http://www.haskell.org/ghc/  :? for help

Loading package ghc-prim ... linking ... done.

Loading package integer ... linking ... done.

imLoading package base ... linking ... done.

poPrelude> import Data.Number.CReal

Could not find module `Data.Number.CReal':

  Use -v to see a list of the files searched for.

Prelude> 2/3

0.***** Exc*** Exception: stack o*** Exception: stack ove*** Exception: stack overflowrflowverflowep*** Exc*** Exception: stack overfloweption: stack overflowtion: stack overflow* Exc*** Exception: stack overfloweption: st*** Exception: stack overflowack o*** Exception: stack overflowverflow

Name: Anonymous 2009-11-19 17:23

>>23
look at me I made a funny

Name: Anonymous 2009-11-19 19:34

>>23
NO EXCEPTIONS

Name: Anonymous 2009-11-19 19:39

$ ghci GHCi, version 6.10.4: http://www.haskell.org/ghc/ :? for help Loading package ghc-prim ... linking ... done. Loading package integer ... linking ... done. Loading package base ... linking ... done. Prelude> 2 / 3 0.6666666666666666 Prelude> :t 2 / 3 2 / 3 :: (Fractional t) => t Prelude>

I love that Haskell has polymorphic literals.

Name: Anonymous 2009-11-19 19:51

float(2/3) divides the integers 2 and 3(resulting in 0) and then converting that 0 into a float(0.0)

Name: Anonymous 2009-11-19 20:48

>>30
Totally, dude.

Prelude> fromInteger (2 `div` 3) :: Float

0.0

Name: Anonymous 2009-11-19 20:55

>>28
Why not? It's pretty awesome to me. Why have silly rules about literals--like that floats must be specified with a period, even when there's nothing after the decimal--when the compiler can infer the meaning for you?

Name: Anonymous 2009-11-19 21:17

Why force things to be decimal-values in the first place?

guile> (/ 2 3)

2/3

Behold, the way things ought to be.

Name: Anonymous 2009-11-20 3:09

>>33
Yes, just like I've shown in >>3

Name: Anonymous 2009-11-20 12:51

>>34
And now we have come full circle.

Christ.

1 Name: Anonymous 2009-11-18 22:37

2 Name: Anonymous 2009-11-18 22:41

3 Name: Anonymous 2009-11-18 22:59

4 Name: Anonymous 2009-11-18 23:07

5 Name: Anonymous 2009-11-18 23:47

6 Name: Anonymous 2009-11-18 23:49

7 Name: Anonymous 2009-11-18 23:56

8 Name: Anonymous 2009-11-19 0:23

9 Name: Anonymous 2009-11-19 0:45

10 Name: Anonymous 2009-11-19 1:14

11 Name: Anonymous 2009-11-19 10:21

12 Name: Anonymous 2009-11-19 11:29

13 Name: Anonymous 2009-11-19 12:24

14 Name: Anonymous 2009-11-19 13:04

16 Name: Anonymous 2009-11-19 14:16

17 Name: Anonymous 2009-11-19 14:19

18 Name: Anonymous 2009-11-19 14:21

19 Name: Anonymous 2009-11-19 14:48

21 Name: Anonymous 2009-11-19 15:37

23 Name: Anonymous 2009-11-19 16:34

24 Name: Anonymous 2009-11-19 17:23

26 Name: Anonymous 2009-11-19 19:34

27 Name: Anonymous 2009-11-19 19:39

29 Name: Anonymous 2009-11-19 19:51

31 Name: Anonymous 2009-11-19 20:48

32 Name: Anonymous 2009-11-19 20:55

33 Name: Anonymous 2009-11-19 21:17

34 Name: Anonymous 2009-11-20 3:09

35 Name: Anonymous 2009-11-20 12:51