Class: Flt::Solver::Base

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

Direct Known Subclasses

RFSecantSolver, SecantSolver

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(context, default_guesses, tol, eqn = nil, &blk) ⇒ Base

default_guesses: nil for no pre-guess, or one or two guesses (use array for two)



10
11
12
13
14
15
16
17
18
 
# File 'lib/solver/base.rb', line 10

def initialize(context, default_guesses, tol, eqn=nil, &blk)
  @context = context
  @default_guesses = Array(default_guesses)
  @x = @default_guesses.first
  @f = eqn || blk
  @tol = tol # user-requested tolerance
  @max_it = 8192
  reset
end

Instance Attribute Details

#iteration ⇒ Object (readonly)

Returns the value of attribute iteration.



65
66
67
 
# File 'lib/solver/base.rb', line 65

def iteration
  @iteration
end

#reason ⇒ Object (readonly)

Returns the value of attribute reason.



65
66
67
 
# File 'lib/solver/base.rb', line 65

def reason
  @reason
end

Instance Method Details

#reset ⇒ Object 



20
21
22
23
24
25
26
 
# File 'lib/solver/base.rb', line 20

def reset
  @l_x = nil
  @fx = nil
  @l_fx = nil
  @ok = true
  @conv = false
end

#root(*guesses) ⇒ Object

value of parameters is used as a guess in precedence to the pre-guesses if not nil use Array for two guesses



30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
 
# File 'lib/solver/base.rb', line 30

def root(*guesses)
  @guess = (guesses + @default_guesses).map{|g| num(g)}
  reset
  @l_x = @x = @guess.first
  @l_fx = @fx = eval_f(@x)
  @ok = true
  @conv = false

  # Minimum tolerance of the numeric type used
  @numeric_tol = Tolerance(1,:ulps) # Tolerance(@context.epsilon, :floating)

  raise "Invalid parameters" unless validate

  @reason = nil
  @iteration = 0
  # TODO: handle NaNs (stop or try to find other guess)
  while @ok && @iteration < @max_it
    next_x = step()
    @l_x = @x
    @l_fx = @fx
    @x = next_x
    @fx = eval_f(@x)
    @conv = test_conv() if @ok
    break if @conv
    @iteration += 1
  end
  @ok = false if @iteration >= @max_it # TODO: set reason
  @x

end

#value ⇒ Object 



61
62
63
 
# File 'lib/solver/base.rb', line 61

def value
  @fx
end