>>>There shoud be a way using LOG10() without counting numbers, but I'm to lazy right now. (For the whole part it's INT(log10(ABS(EVL(INT(tnNumber),1))))+1 )
>>
>>Understood!
>>Thank you.
>
>Hi Bill,
>
>I did not found a simple way to calculater the decimal digits wit LOG.
>So the kludge for stuff based 2: (I had some fun with it):
>

>CLEAR
>
>?GetCommonFract_2(1)
>?GetCommonFract_2(0)
>?GetCommonFract_2(13/32)
>?GetCommonFract_2(0.25)
>?GetCommonFract_2(9/16)
>?GetCommonFract_2(31/16)
>?GetCommonFract_2(-15.125)
>
>FUNCTION GetCommonFract_2
> LPARAMETERS;
>  tnNumber
>
> LOCAL;
>  lnWhole,;
>  lnFrac,;
>  lnNominator
>
> llSign      = SIGN(tnNumber)=-1
> tnNumber    = ABS(tnNumber)
> lnWhole     = INT(tnNumber)
> lnFrac      = tnNumber-lnWhole
> lnNominator = 2^(LEN(RTRIM(STR(lnFrac,15,15),"0"))-1)
>
> RETURN IIF(llSign,'-','')+;
>  IIF(EMPTY(lnWhole),IIF(EMPTY(lnFrac),'0',''),LTRIM(STR(lnWhole,15))+' ')+;
>  IIF(EMPTY(lnFrac),'',LTRIM(STR(lnFrac*lnNominator,15))+'/'+LTRIM(STR(lnNominator,15)))
>ENDFUNC &&GetCommonFract_2
>

>
>Edit: added parenthesis on 2^....

Wouldn't

lnNominator = 2^(int(LEN(RTRIM(STR(lnFrac,15,15),"0")*log(10)/log(2)))+1)

be more correct? Because for three decimal digits you need two to the power of ten to have your error below 0.001... and 3*log(10)/log(2) is 9.9658, and the +1 there gives you 10.