Par2: Decimal to fraction 2011-05-05 -- Geoff Robinson as others have stated to convert a fraction to a decimal just divide the numerator by the
denominator.
going the other way is trickier 8-)
I wrote the following seven years ago (based on C code I had written back in June 1992)
when the question came up in a
newsgroup, and have tweaked it a bit today...
it is based on Euclid's algorithm
HTH
Geoff R
!--------------------------------------------------------------------------
VitCreateFraction FUNCTION (STRING p:Str)
! Written by Geoff Robinson, Vitesse Information Systems P/L, vitesse@mira.net
! Date: 4 May 2004 (tweaks to allow for negatives seven years later on 5&6 May 2011)
! - Assumes passed string holds valid number
! Feel free to use at own risk!
L:Len LONG,AUTO
i LONG,AUTO
u LONG,AUTO
v LONG,AUTO
Numerator LONG
Denominator LONG,AUTO
WholeNumber STRING(32)
DecPoint EQUATE('.') ! some countries may use a comma instead of dot
L:Negative BYTE
CODE
p:Str = left(p:Str)
L:Len = len(clip(p:Str))
if L:Len
if p:Str[L:Len] = '-' ! allow for trailing negative
L:Negative = TRUE
p:Str[L:Len] = ' '
end
if p:Str[1] = '-' ! allow for leading negative
L:Negative = TRUE
p:Str[1] = ' '
p:Str = left(p:Str)
end
if L:Negative then L:Len = len(clip(p:Str)). ! adjust length
end
if ~L:Len then return(''). ! blank string or only negative sign(s) passed over...
i = instring(DecPoint,p:Str,1,1) !find the decimal point
if ~i ! no decimal point found
WholeNumber = p:Str
else
if i > 1
WholeNumber = p:Str[1 : i - 1] ! get whole number
end
if i < L:Len
Numerator = p:Str[i + 1 : L:Len] ! get decimal fraction digits for the
numerator
end
end
if ~Numerator
! no decimal fraction to work with eg. '1.000'
return(choose(~L:Negative,'','-') & clip(WholeNumber))
end
Denominator = '1' & all('0',L:Len - i) ! get the initial denominator
v = Numerator
u = Denominator
! get the greatest common divisor based on Euclid's algorithm
LOOP
u = u % v
if ~u then break.
! swap u and v
i = u
u = v
v = i
END!loop
return( choose(~L:Negative,'','-') & |
choose(WholeNumber <> 0,clip(WholeNumber) & ' ','') & |
Numerator/v & '/' & Denominator/v )
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