From: Vincent Arnoux <vincent.arnoux@...>
Date: 2006-09-19T21:41:33+09:00
Subject: Pi limited to 15 digits ?

Hello,
I am trying to calculate pi in an arithmetical way with a big number of
decimal digits.
Unfortunately, the code below only displays 15 digits. How can I ask for
more digits ?

require 'bigdecimal'

puts("Enter precision : ")
precision = gets.chomp.to_i

i, sign = 1.0, 1
value = BigDecimal.new("0")
pi = BigDecimal.new("0")

precision.times do
    value += 1/i * sign
    sign *= -1
    i += 2
end

pi = 4 * value
puts pi.to_s

Vincent