> No, no, no. > Don't use Float. > Float are INEXACT > > (( 0.33333 asScaledDecimal: 5 )+ (0.33333 asScaledDecimal: 5 ) ) *6 = > 3.99996s5 > -> FALSE ! > > Nicolas
> I don't know what ScaledDecimal expectations are or should be. > By now, you are in charge or performing the rounding operation by yourself > > ( (1/3) asScaledDecimal: 2) roundTo: 0.01s2. > > We may add more convenient #roundToPrecision, and #roundToPrecision: > But you could also truncate, fllor or ceil... > > Nicolas > On Fri, May 20, 2011 at 7:57 AM, Ralph Boland <rpbol...@gmail.com> wrote: >> Dealing with ScaledDecimal is a complicated matter and I have probably failed >> to appreciate many of the complications but whoever is implementing >> ScaledDecimal >> (and Smalltalk needs ScaledDecimal) needs to appreciate those complications. >> Anybody here a financial expert? >> > > I am not a financial expert, but this is how ScaledDecimal works, in > both Squeak/Pharo and I believe other implementations, too. > > I did run into this previously and it bugged me enough that I created > FixedDecimal (at http://www.squeaksource.com/FixedDecimal.html ). It > does not keep an internal more precise number - it keeps exactly what > it shows you. (Although the implementation is somewhat odd - it does > do what it is supposed to do.) > > -Chris > After Your considerations i do this conclusion for manage ScaledDecimal instance with SIXX. 1) the instance reference into the SIXX declaration is based on the ScaledDecimal notation : 1234.333s3 '<sixx.object sixx.id="0" sixx.type="ScaledDecimal" >1234.333s3</sixx.object> ' 2) All the translation is based on it. Other think is the internal ScaledDecimal represent. It's important to rounding the data so that the numerator and denominator are integer. I do it wtih method : roundToPrecision: scalePrecision | rnd | rnd:= ScaledDecimal new setNumerator: 1 denominator: (10 raisedTo: scalePrecision) scale: scalePrecision. ^self roundTo: rnd The round is automatic when i create ScaledDecimal instance with: fromString: aString For example when converter a input string to ScaledDecimal instance based on number of digit typed. It's required when i do conversion from another Number type: ( 1/3 asScaledDecimal: 3 ) roundToPrecision It's all for now. Any pointers would be greatly appreciated ! Thanks, Dario
