Probably a bug, though there is this situation:
for i:a thru b step s do (s:-s)
is the termination test i>s or i<s ?
I think this issue came up in the Algol 60 definition. The Maxima user
language is modeled on Algol 60, in case
you didn't know.
RJF
/
/Adam Majewski wrote:
> Michel Talon pisze:
>
>> Adam Majewski wrote:
>>
>>
>>> for radius:4 thru 1 step -1 do disp(radius);
>>>
>> (%i5) for radius:4 thru 1 step ''s do disp(radius);
>> 4
>>
>> 3
>>
>> 2
>>
>> 1
>>
>>
>>
>>
> Thx for answer, it works.
> Why '' is needed only for step (increment), not for other values :
> initial_value, limit ?
>
> --------------- first example (not works)-------------------
> (%i1) s:-1;
> rMax:4;
> rMin:1;
> for radius:rMax thru rMin step s do disp(radius);
> (%o1) -1
> (%o2) 4
> (%o3) 1
> (%o4) done
> ------------------second example (works) ----------------------
> (%i5) s:-1;
> rMax:4;
> rMin:1;
> for radius:rMax thru rMin step ''s do disp(radius);
> (%o5) -1
> (%o6) 4
> (%o7) 1
> 4
> 3
> 2
> 1
> (%o8) done
>
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