[Scilab-users] Confusion about types (typeof vs. Variabe Browser)

[Stéphane Mottelet]

Hello Frederico

Le 11/12/2019 à 15:25, Federico Miyara a écrit :
>
> Stéphane,
>
> I'm not sure whether you are proposing to modify types, type names or 
> just how they are presented in the variable browser.
As far as my previous message is concerned, I was just making a proposal 
for names in the variable browser
>
> I think, from the user's perspective, that the type names appearing in 
> the variable browser (in the Type column) should be strictly the same 
> as reported by the function typeof. Otherwise it can and will cause 
> confusion and the sensation of lack of consistency.
So do I. But other users do not agree with that, that's why I am trying 
to find a sensible compromise...
>
> I also think types should reflect three things:
>
> 1) The way a variable is stored in memory, including the headers and 
> the data with the basic format corresponding to each case.
>
> 2) The set of possible values or elements compatible with the type.
>
> 3) The functions and operators that can be applied to a given type of 
> data (without overloading) and the way they work.
>
> According to this, a complex number would have definitely a different 
> type from a real number since the way it is stored is different. By 
> the way, calling non-complex numbers type "real" wouldn't be 
> completely accurate, since they are really a subset of rationals with 
> a power-of-ttwo denominator; however it would be acceptable because 
> they are meant to approximate real numbers.
>
> Finally, I don't consider it recommendable that the same word be used 
> both for a /format /and a /type name/, such as if "constant" were 
> replaced by "double".
What do you mean by "format" ?
>
> In the case of integers, are all integers the same type?  Is int16 the 
> same type as int32?
>
> I tend to think the answer is no, since they have very different 
> storage representations, cover different sets of numbers and even 
> operations behave differently. If so, the type should be called 
> integer8, integer16 and so on (so the type would be integer8 and the 
> basic format would be int16 --no ambiguity). If, on the contrary, they 
> are the same, then the only type name should be "integer" and the 
> basic format should be informed in a different column.
>
That was my attempt, by using parenthesis.

S.


> Regards,
>
> Federico Miyara
>
>
>
>
>
> On 10/12/2019 06:47, Stéphane Mottelet wrote:
>>
>> After thinking about it and after looking to other softwares, my 
>> proposition would be to concentrate on the set theoritic name + use 
>> parenthesis for details of storage
>>
>> typeof(x)=="constant" && isreal(x)==%t && issparse(x)=%f : Real
>>
>> typeof(x)=="constant" && isreal(x)==%f && issparse(x)=%f : Complex
>>
>> typeof(x)=="constant" && isreal(x)==%t && issparse(x)=%t : Real (sparse)
>>
>> typeof(x)=="constant" && isreal(x)==%f && issparse(x)=%t : Complex 
>> (sparse)
>>
>> typeof(x)=="boolean" && issparse(x)=%f : Boolean
>>
>> typeof(x)=="boolean" && issparse(x)=%t : Boolean (sparse)
>>
>> For integers, since their use is rather specific to more advanced 
>> users, i suggest to display the storage type to differentiate them
>>
>> type(x)==8 && inttype(x)==1 : Integer (int8)
>>
>> type(x)==8 && inttype(x)==11 : Integer (uint8)
>>
>> and so on...
>>
>> However, I don't understand why we should consider Scilab users as 
>> less aware (or less concerned by) of the reality of storage types. 
>> When you consider the big audience of Matlab and see that developpers 
>> didn't waste time like we do here. They just use "double", litteral 
>> integer types (int8,...). Moreover they didn't even have to make 
>> translations....
>>
>> S.
>>
>> Le 09/12/2019 à 09:44, Stéphane Mottelet a écrit :
>>>
>>> Hello all,
>>>
>>> Le 06/12/2019 à 23:37, Samuel Gougeon a écrit :
>>>> Le 06/12/2019 à 23:23, Federico Miyara a écrit :
>>>>>
>>>>> .../...
>>>>> By the way, if constant were changed to double (or to number or 
>>>>> num.ber --I don't get the dot...
>>>>
>>>> As in 3.14, contrarily to 123
>>>>
>>>
>>> If "double" is not to be used for reasons that I still don't 
>>> understand, why don't we use "Real" instead of "Number" for x such 
>>> that typeof(x)==constant and isreal(x)==%t ? This would be 
>>> consistent with "complex" when typeof(x)==constant and isreal(x)==f. 
>>> Moreover, this would be even set-theory compliant, i.e. use the name 
>>> of the smallest set corresponding to storage type.
>>>
>>>
>>>>
>>>>> --), then as this might cause some backward compatibility, 
>>>>> consider taking the oportunity also to replace "ce" by "cell", and 
>>>>> "st" by "struct", 
>>>>
>>>> Definitely, or even with their possible translation in locales, as 
>>>> for other main native types.
>>>>
>>>>
>>>>
>>>>
>>>> _______________________________________________
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>>> -- 
>>> Stéphane Mottelet
>>> Ingénieur de recherche
>>> EA 4297 Transformations Intégrées de la Matière Renouvelable
>>> Département Génie des Procédés Industriels
>>> Sorbonne Universités - Université de Technologie de Compiègne
>>> CS 60319, 60203 Compiègne cedex
>>> Tel : +33(0)344234688
>>> http://www.utc.fr/~mottelet
>>>
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>> -- 
>> Stéphane Mottelet
>> Ingénieur de recherche
>> EA 4297 Transformations Intégrées de la Matière Renouvelable
>> Département Génie des Procédés Industriels
>> Sorbonne Universités - Université de Technologie de Compiègne
>> CS 60319, 60203 Compiègne cedex
>> Tel : +33(0)344234688
>> http://www.utc.fr/~mottelet
>>
>> _______________________________________________
>> users mailing list
>> users at lists.scilab.org
>> http://lists.scilab.org/mailman/listinfo/users
>
>
> _______________________________________________
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-- 
Stéphane Mottelet
Ingénieur de recherche
EA 4297 Transformations Intégrées de la Matière Renouvelable
Département Génie des Procédés Industriels
Sorbonne Universités - Université de Technologie de Compiègne
CS 60319, 60203 Compiègne cedex
Tel : +33(0)344234688
http://www.utc.fr/~mottelet

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