Sha256: a9ab5b1e7e3afe819eae212af0ef3963ccb86ab4009d6997c14af2e5d61c6569
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Size: 645 Bytes
Versions: 6
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Stored size: 645 Bytes
Contents
module Dydx
class Integrand
attr_accessor :function, :var
def initialize(function, var)
@function = function
@var = var
end
def [](a, b, n = 100)
f = function
a, b = [a, b].map(&:to_f)
raise ArgumentError, 'b should be greater than a' if a > b
# HOT FIX: should implement Infinity class
a = - 1000 if a == - Float::INFINITY
b = 1000 if b == Float::INFINITY
h = (b - a) / n
sum = 0.0
xi = ->(i){ a + h * i }
n.to_i.times do |i|
sum += ( f(xi.(i)) + 4.0 * f(xi.(i) + h / 2.0 ) + f(xi.(i) + h) )
end
( h * sum ) / 6.0
end
end
end
Version data entries
6 entries across 6 versions & 1 rubygems