class Dydx::Integrand
Attributes
function[RW]
var[RW]
Public Class Methods
new(function, var)
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# File lib/dydx/integrand.rb, line 5 def initialize(function, var) @function = function @var = var end
Public Instance Methods
[](a, b, n = 1000)
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# File lib/dydx/integrand.rb, line 10 def [](a, b, n = 1000) # HOT FIX: should implement Infinity class a = - 1000 if a == - Float::INFINITY b = 1000 if b == Float::INFINITY a, b = [a, b].map(&:to_f) fail ArgumentError, 'b should be greater than a' if a > b $temp_cal_f = function n = [n, (b - a) * 2].max n += 1 if n.to_i.odd? h = (b - a) / n x = ->(i) { a + h * i } odd_sum = (1..n - 1).to_a.select(&:odd?).inject(0) { |sum, i| sum += f(x.(i)) } even_sum = (1..n - 1).to_a.select(&:even?).inject(0) { |sum, i| sum += f(x.(i)) } round_8( (h / 3) * (f(a) + f(b) + 2 * even_sum + 4 * odd_sum) ) end
f(vars)
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# File lib/dydx/integrand.rb, line 29 def f(vars) temp_cal_f(vars) end
round_8(num)
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# File lib/dydx/integrand.rb, line 33 def round_8(num) return num if num.abs == Float::INFINITY (num * 10 ** 8).round * 10.0 ** (-8) end