[Scilab-users] [Scilab-Dev] algebra conventions with integer types to be discussed

[Samuel Gougeon]

Le 19/09/2018 à 11:24, Stéphane Mottelet a écrit :
> Le 19/09/2018 à 11:17, Samuel Gougeon a écrit :
>>
>> The current implementation is not incoherent.
> However, there are still bugs, and when trying to solve them, the 
> question of incoherence raises. See e.g :
>
> --> int8(-128)/int8(-1)
>  ans  =
>  -128

There is no bug here. The division yields 128, that then is wrapped, 
what yields -128, since in Scilab after the int8 127, 127+1 goes to -128 
instead of ceiling to 127 like in Octave:
 >> int8(-128)/int8(-1)
ans = 127

At first sight, Octave's result does not look more consistent than 
Scilab's one.
But following its own ceiling/flooring rules, yet it is consistent.

With both possible rules, wrapping or saturating ones, results may 
appear as inconsistent. But for this example, it is not the case.

Samuel