Configuring Maxima output as an improper fraction?

Hi Luke,

for better readability in an e-mail I use
(%i1) display2d:false$

I guess you are dealing with positive numbers. So the following works for positive numbers.

(%i2) x: 23/7$
(%i3) f(x):= [floor(x), mod(x,1)]$
(%i4) f(x);
(%o4) [3,2/7]

If this representation fits your needs you can format your results with such a function. The 
computation backwards is done by an apply "+" or by accessing the list entries via 
%[1]+%[2].

(%i5) apply("+",%);
(%o5) 23/7

If you really want to print the "+" here is a quick hack:

(%i6) :lisp(defun $unsimplified_plus (a b) `((mplus simp) ,b ,a))
$UNSIMPLIFIED_PLUS
(%i6) f(x):= unsimplified_plus(floor(x), mod(x,1))$
(%i7) f(x);
(%o7) 3+2/7

This unsimplified "+" can be reevaluated by two single quotes:

(%i8) ''%;
(%o8) 23/7


And there is another one:

(%i9) f(x):= sconcat(floor(x), "+", mod(x,1))$
(%i10) f(x);
(%o10) "3+2/7"  

This is a string. (In the default - display2d:true - mode you won't see the quotes.)

(%i11) eval_string(%);
(%o11) 23/7


HTH
Volker van Nek


Am 29 Jan 2009 um 13:21 hat Luke Scharf geschrieben:

> Is there a way to configure Maxima to output the result as an improper
> fraction?
> 
> For instance, if I enter 3/4+3/4, then it outputs 3/2.  Since I'm doing
> arithmetic for a woodworking project, it would be easier if it would
> output as 1+1/2.  Or 1+4/8 would be super-useful, too.  Is there a way
> to make Maxima to do that?
> 
> Many thanks!
> -Luke
> 
> P.S. Please CC me -- I'm not subscribed to the list.
> 
> P.P.S. I'm impressed with Maxima -- after using Mathematica and Matlab,
> I'm thrilled to find a mature open-source computer algebra system!  With
> wxMaxima, I'll certainly be recommending it to many people!
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