Dolphin shows the same behaviour. I added the following method to ScaledDecimal
to help:
roundedByScale
| scaleFactor |
scaleFactor := 10 ** scale.
^(ScaledDecimal newFromNumber: (fraction * scaleFactor) rounded scale:
scale) / scaleFactor
Translating slightly for Pharo:
roundedByScale
| scaleFactor |
scaleFactor := 10 ** scale.
^(ScaledDecimal newFromNumber: (self * scaleFactor) rounded scale:
scale) / scaleFactor
You can then do:
(82 - (2 * 35.9) - (0 / 2) * (113/121) asScaledDecimal: 1) roundedByScale =
9.5s1 "true"
HTH.
John
> On 1 Sep 2020, at 05:17, Esteban Maringolo <emaring...@gmail.com> wrote:
>
> As a follow up to this, adding a roundTo: before converting into a
> ScaledDecimal does not work.
>
> (((91 - (2 * 35.9) - (0 / 2) * (113/121)) roundTo: 0.1)
> asScaledDecimal: 1) = 17.9s1
>
> So how do you compare two ScaledDecimals that _should_ be the same?
>
> Regards!
>
> Esteban A. Maringolo
>
> On Tue, Sep 1, 2020 at 1:07 AM Esteban Maringolo <emaring...@gmail.com> wrote:
>>
>> Hi,
>>
>> I was doing some basic calculations based on a formula, and I wanted
>> to convert the result to a scaled decimal in order to avoid having
>> these "loose" decimals in 10th position or something similar.
>>
>> So I did the following:
>> 82 - (2 * 35.9) - (0 / 2) * (113/121) asScaledDecimal: 1 -> 9.5s1
>>
>> But When I do this in a test:
>> (82 - (2 * 35.9) - (0 / 2) * (113/121) asScaledDecimal: 1) = 9.5s1
>>
>> It fails because the comparison returns false.
>>
>> I guess this is the proper behavior, but I'd expected that the
>> conversion from a Float to a scaled decimal would have eliminated the
>> extra precision from the formula.
>>
>> I can do a roundTo: 0.1 before converting, but I'd like to know what
>> would be the proper way of dealing with this.
>>
>> Thanks!
>>
>> Esteban A. Maringolo
>
