Question

Is there a simple method to (attempt to) rationalize all numeric values in an expression within a given delta, much like Rationalize[] in Mathematica?

An example in Mathematica:

In[25]:= Rationalize[0.5 x^2 - 3.333333 x, 10^-4]
Out[25]= x^2/2-(10 x)/3

I see the nsimplify() function, but that seems like overkill.

Answer 1

I don’t see how nsimplify is over kill. nsimplify does exactly what you want, because you can pass it a SymPy expression, and it will rationalize the terms in the expression

>>> print nsimplify(0.5*x**2 - 3.333333*x, tolerance=0.001, rational=True)
x**2/2 - 3333333*x/1000000

(the tolerance keyword doesn’t seem to work, which I guess is a bug).