MuPAD seems to always simplify fractions so that they are irreducible. For instance, 15/9 is displayed as 5/3. I would like to know if there is a way to display the unreduced fraction instead.
MATLAB: How to deactivate automatic reduction of fractions in MuPAD
cancellationsimplificationSymbolic Math Toolbox
Related Solutions
That is not possible, and it is unlikely to ever be an option. Symbolic engines often have internal rewriting rules to put things into "canonical form" to make it easier to determine whether expressions are equal, which can be very important for reducing memory use and for performance reasons.
The internal symbolic engine (MuPAD) mechanism for postponing evaluation is to use hold() . Each evaluation strips off one layer of hold() . For example if you open a MuPad notebook and command
hold(hold(3))*hold(hold(5))then because one layer of hold is stripped off at execution time, the result would be
hold(3)*hold(5)If you had tried hold(3)*hold(5) directly then because one hold would be stripped off, you would get 15 directly .
There is no MATLAB interface provided for hold. You can try things like,
Hold = @(V) feval(symengine, 'hold', V)Hold(3)*Hold(5)but the result you will get will be
Warning: Unable to display symbolic object because 'symengine' was reset. Repeat commands to regenerate result. > In sym/disp (line 44) In sym/display>displayVariable (line 85) In sym/display (line 47)syms xsympref('FloatingPointOutput',true);(1/2)*(3*x^2)
sympref('FloatingPointOutput',false);(1/2)*(3*x^2)
Best Answer