Arithmetic-geometric mean: Difference between revisions

=={{header|EchoLisp}}==

We use the '''(~= a b)''' operator which tests for |a - b| < ε = (math-precision).

<lang scheme>

(lib 'math)

(define (agm a g)

(if (~= a g) a

(agm (// (+ a g ) 2) (sqrt (* a g)))))

(math-precision)

→ 0.000001 ;; default

(agm 1 (/ 1 (sqrt 2)))

→ 0.8472130848351929

(math-precision 1.e-15)

→ 1e-15

(agm 1 (/ 1 (sqrt 2)))

→ 0.8472130847939792

</lang>