Class: RootSolver::Bisection

Inherits:
Object
  • Object
show all
Defined in:
lib/root_solver.rb

Instance Method Summary collapse

Constructor Details

#initialize(f, low, high, tol = 0.01, n = 10) ⇒ Bisection

Returns a new instance of Bisection.



33
34
35
36
37
38
39
 
# File 'lib/root_solver.rb', line 33

def initialize(f, low, high, tol = 0.01, n = 10)
  @f    = f
  @tol  = tol
  @n    = n
  @high = high
  @low  = low
end

Instance Method Details

#solve(f = @f, low = @low, high = @high, tol = @tol, n = @n) ⇒ Object 



41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
 
# File 'lib/root_solver.rb', line 41

def solve(f = @f, low = @low, high = @high, tol = @tol, n = @n)
  x = (high + low) / 2
  y = f.call(x)

  if y.abs < tol #successfully found root
    x
  elsif n <= 0 #break out of solver after so many iterations
    x
  elsif x_converge?(low, high, tol) && !crossing?(f, low, high)
    raise NoRootError.new
  else #narrow window of searching by half
    if y > 0
      high = x
    else
      low = x
    end
    solve(f, low, high, tol, n - 1)
  end
end