41 lines
851 B
Ruby
41 lines
851 B
Ruby
#!/usr/local/bin/ruby
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# frozen_string_literal: false
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#
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# nlsolve.rb
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# An example for solving nonlinear algebraic equation system.
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#
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require "bigdecimal"
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require "bigdecimal/newton"
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include Newton
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class Function # :nodoc: all
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def initialize()
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@zero = BigDecimal("0.0")
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@one = BigDecimal("1.0")
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@two = BigDecimal("2.0")
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@ten = BigDecimal("10.0")
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@eps = BigDecimal("1.0e-16")
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end
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def zero;@zero;end
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def one ;@one ;end
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def two ;@two ;end
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def ten ;@ten ;end
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def eps ;@eps ;end
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def values(x) # <= defines functions solved
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f = []
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f1 = x[0]*x[0] + x[1]*x[1] - @two # f1 = x**2 + y**2 - 2 => 0
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f2 = x[0] - x[1] # f2 = x - y => 0
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f <<= f1
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f <<= f2
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f
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end
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end
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f = BigDecimal.limit(100)
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f = Function.new
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x = [f.zero,f.zero] # Initial values
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n = nlsolve(f,x)
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p x
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