ackermann should fit, no?
On Feb 23, 2012, at 12:09 AM, Neil Toronto wrote: > Inspired by the Game of Life tweet challenge (that was seriously cool, for a > geeky definition of "cool"), I compressed a program that calculates pi to > arbitrary precision. By my count, this is 132 characters, after removing > comments and extra whitespace: > > > ;; Computes a converging approximation of (atan x) with alternating > ;; signs, if x is in (0,1] > (define (q x n) > (if (= n 0) > x > (- (let ([y (+ 1 (* n 2))]) > (/ (expt x y) y)) > (q x (- n 1))))) > > ;; Computes pi to arbitrary precision (higher n is better) using > ;; Machin's formula > (define (pi n) > (abs (- (* 16 (q 1/5 n)) > (* 4 (q 1/239 n))))) > > > For example, (real->decimal-string (pi 141) 200) computes pi to 200 decimal > places. > > What's your favorite not just computable, but tweetable function? :) > > Neil ⊥ > ____________________ > Racket Users list: > http://lists.racket-lang.org/users ____________________ Racket Users list: http://lists.racket-lang.org/users
