[Scilab-users] create random values between [-1,1]

[Stéphane Mottelet]

Le 10/06/2016 à 16:19, Stéphane Mottelet a écrit :
> Le 10/06/2016 à 15:59, Jens Simon Strom a écrit :
>> rand(n,1)–rand(n,1) is definitely NOT uniform.
> by convolution the density of such a variable  seems triangle shaped :
>
> f(x)=1/2-abs(x)/4, if x \in [-2,2]
>      =0, elsewhere
oops, rather

f(x)=1/2-abs(x)/2, if x \in [-1,1]

sorry...

S.
>
>
> S.
>
>
>> Jens
>> ------------------------------------------------------------------------------
>> Am 10.06.2016 15:33, schrieb Samuel Gougeon:
>>> Le 10/06/2016 15:21, Carrico, Paul a écrit :
>>>>
>>>> Hi
>>>>
>>>> In order to simulate dimensional tolerances in +/-, I’m using the 
>>>> following workaround :
>>>>
>>>> n = 100;
>>>>
>>>> a = rand(n,1) – rand(n,1);
>>>>
>>>> Of course I need to increase the N value to the domain … is there a 
>>>> more “clever” way ?
>>>>
>>> grand(n,1,"unf",-1,1)
>>>
>>> BTW, i am not sure that rand(n,1)–rand(n,1)  builds (or keeps) a 
>>> uniform distribution over [-1, 1].
>>>
>>> Samuel
>>>
>>>
>>>
>>> _______________________________________________
>>> users mailing list
>>> users at lists.scilab.org
>>> http://lists.scilab.org/mailman/listinfo/users
>>
>>
>>
>> _______________________________________________
>> users mailing list
>> users at lists.scilab.org
>> http://lists.scilab.org/mailman/listinfo/users
>
>
> -- 
> Département de Génie Informatique
> EA 4297 Transformations Intégrées de la Matière Renouvelable
> Université de Technologie de Compiègne -  CS 60319
> 60203 Compiègne cedex
>
>
> _______________________________________________
> users mailing list
> users at lists.scilab.org
> http://lists.scilab.org/mailman/listinfo/users


-- 
Département de Génie Informatique
EA 4297 Transformations Intégrées de la Matière Renouvelable
Université de Technologie de Compiègne -  CS 60319
60203 Compiègne cedex

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.scilab.org/pipermail/users/attachments/20160610/c28a3aab/attachment.htm>