@code{(require 'rationalize)} @ftindex rationalize @defun rationalize x e Computes the correct result for exact arguments (provided the implementation supports exact rational numbers of unlimited precision); and produces a reasonable answer for inexact arguments when inexact arithmetic is implemented using floating-point. @end defun @code{Rationalize} has limited use in implementations lacking exact (non-integer) rational numbers. The following procedures return a list of the numerator and denominator. @defun find-ratio x e @code{find-ratio} returns the list of the @emph{simplest} numerator and denominator whose quotient differs from @var{x} by no more than @var{e}. @format @t{(find-ratio 3/97 .0001) @result{} (3 97) (find-ratio 3/97 .001) @result{} (1 32) } @end format @end defun @defun find-ratio-between x y @code{find-ratio-between} returns the list of the @emph{simplest} numerator and denominator between @var{x} and @var{y}. @format @t{(find-ratio-between 2/7 3/5) @result{} (1 2) (find-ratio-between -3/5 -2/7) @result{} (-1 2) } @end format @end defun