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Message from discussion Python comparing float
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Date: Tue, 28 Aug 2012 20:25:58 +0100
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Subject: Re: [pygame] Python comparing float
From: Russell Jones <russell.jo...@gmail.com>
To: pygame-us...@seul.org
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Alternatively, in the numpy module (part of the Scientific Tools for Python
http://www.scipy.org/ ) there is the linspace function, which you could use
like this
for x in numpy.linspace(0,2,21):
    print(x)

Russell

On 23 August 2012 14:34, Ricardo Franco <ricardo.kr...@gmail.com> wrote:

> Well, this is a good idea, I go do this way. tks
>
>
> 2012/8/22 Greg Ewing <greg.ew...@canterbury.ac.nz>
>
>> Ricardo Franco wrote:
>>
>>>     That's why when you are comparing floating point numbers, you always
>>>     have to check if they are within some small error value from each
>>>     other. How large that value is depends on your particular use case.
>>>
>>
>> It's even better if you can avoid comparing floats for
>> equality at all. You can do that in this case by using an
>> integer loop counter and computing the float value from it:
>>
>> >>> for i in xrange(11):
>> ...    rate = 1.0 + i * 0.1
>> ...    print rate
>> ...
>> 1.0
>> 1.1
>> 1.2
>> 1.3
>> 1.4
>> 1.5
>> 1.6
>> 1.7
>> 1.8
>> 1.9
>> 2.0
>>
>> --
>> Greg
>>
>
>
>
> --
> Ricardo Franco Andrade             @ricardokrieg
>
> ( Game | Desktop | Web ) Developer
>
> email: ricardo.kr...@gmail.com
> contact: +55 (86) 9958 9725
>              +55 (86) 9436 0830
> twitter: twitter.com/ricardokrieg
> facebooK: https://www.facebook.com/krieg.ricardo
> github: https://github.com/ricardokrieg
>
>

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Alternatively, in the numpy module (part of the Scientific Tools for Python=
=C2=A0<a href=3D"http://www.scipy.org/">http://www.scipy.org/</a>=C2=A0) th=
ere is the linspace function, which you could use like this<div>for x in nu=
mpy.linspace(0,2,21):</div>
<div>=C2=A0 =C2=A0 print(x)<br><br>Russell<br><br><div class=3D"gmail_quote=
">On 23 August 2012 14:34, Ricardo Franco <span dir=3D"ltr">&lt;<a href=3D"=
mailto:ricardo.kr...@gmail.com" target=3D"_blank">ricardo.kr...@gmail.com</=
a>&gt;</span> wrote:<br>
<blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1p=
x #ccc solid;padding-left:1ex"><div>Well, this is a good idea, I go do this=
 way. tks<div><div class=3D"h5"><br><br><div class=3D"gmail_quote">2012/8/2=
2 Greg Ewing <span dir=3D"ltr">&lt;<a href=3D"mailto:greg.ewing@canterbury.=
ac.nz" target=3D"_blank">greg.ew...@canterbury.ac.nz</a>&gt;</span><br>

<blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1p=
x #ccc solid;padding-left:1ex"><div>Ricardo Franco wrote:<br>
<blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1p=
x #ccc solid;padding-left:1ex">
=C2=A0 =C2=A0 That&#39;s why when you are comparing floating point numbers,=
 you always<br>
=C2=A0 =C2=A0 have to check if they are within some small error value from =
each<br>
=C2=A0 =C2=A0 other. How large that value is depends on your particular use=
 case.<br>
</blockquote>
<br></div>
It&#39;s even better if you can avoid comparing floats for<br>
equality at all. You can do that in this case by using an<br>
integer loop counter and computing the float value from it:<br>
<br>
&gt;&gt;&gt; for i in xrange(11):<br>
... =C2=A0 =C2=A0rate =3D 1.0 + i * 0.1<br>
... =C2=A0 =C2=A0print rate<br>
...<br>
1.0<br>
1.1<br>
1.2<br>
1.3<br>
1.4<br>
1.5<br>
1.6<br>
1.7<br>
1.8<br>
1.9<br>
2.0<span><font color=3D"#888888"><br>
<br>
-- <br>
Greg<br>
</font></span></blockquote></div><br><br clear=3D"all"><div><br></div></div=
></div><div class=3D"im">-- <br>Ricardo Franco Andrade=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 @ricardokrieg<br><br>( =
Game | Desktop | Web ) Developer<br><br>email: <a href=3D"mailto:ricardo.kr=
i...@gmail.com" target=3D"_blank">ricardo.kr...@gmail.com</a><br>

contact:=C2=A0<a href=3D"tel:%2B55%20%2886%29%209958%209725" value=3D"+5586=
99589725" target=3D"_blank">+55 (86) 9958 9725</a><div>=C2=A0 =C2=A0 =C2=A0=
 =C2=A0 =C2=A0 =C2=A0 =C2=A0<a href=3D"tel:%2B55%20%2886%29%209436%200830" =
value=3D"+558694360830" target=3D"_blank">+55 (86) 9436 0830</a>=C2=A0<br>
twitter: <a href=3D"http://twitter.com/ricardokrieg" target=3D"_blank">twit=
ter.com/ricardokrieg</a><br><div>facebooK:=C2=A0<a href=3D"https://www.face=
book.com/krieg.ricardo" target=3D"_blank">https://www.facebook.com/krieg.ri=
cardo</a></div>

</div><div>github:=C2=A0<a href=3D"https://github.com/ricardokrieg" target=
=3D"_blank">https://github.com/ricardokrieg</a></div><br>
</div></div>
</blockquote></div><br></div>

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