constants - Evaluate Irrational with Julia -

julia has built-in constant pi, type irrational.

julia> pi π = 3.1415926535897...  julia> π π = 3.1415926535897...  julia> typeof(pi) irrational{:π} 

coming sympy, has n() function, evaluate pi (or other irrationals, such e, golden, etc.) n digits.

in [5]: n(pi, n=50) out[5]: 3.1415926535897932384626433832795028841971693993751 

is possible? assuming pi based on mathematical definition, rather thirteen decimal places.

sure, can set bigfloat precision , use big(π). note precision binary; it's counted in bits. should safe if set precision @ least log2(10) + 1 times number of digits need.

example:

julia> setprecision(bigfloat, 2000)            @printf "%.200f" big(π)        end 3.14159265358979323846264338327950288419716939937510582097494459230781640628620899862803482534211706798214808651328230664709384460955058223172535940812848111745028410270193852110555964462294895493038196 

here i've set precision little higher needs 200 digits.

the digits computed in gnu mpfr library.