I need to compute a recursive sequence of numbers. In the formula, I need to compute B(r) where B(x) is a polynomial with rational coefficients (i.e fractions) and r is a rational number. My code is
def B(x):
return x**2-x+1/6
However, when I plug r in, I get a floating number, not a rational number. This is expected.
I have several polynomials like this and my formula involves addition/subtraction with these numbers. How can I return the final result as a rational number?
Thanks!
As stated in the comments, the fractions module is really helpful.
from fractions import Fraction
def B(x):
x = Fraction(x)
return x**2-x + Fraction(1,6)
Basically, x**2-x doesn't have division, it doesn't need to be a Fraction. Because 1/6 would become a floating point number, use Fraction('1/6') or Fraction(1,6). Math with a Fraction input will return a Fraction. Putting x = Fraction(x) at the top allows for fractional inputs.