class CAS::Acos

Representation for the `arccos(x)` function. It is implemented as a `CAS::Op`. It is the inverse of the `cos(x)` function

Public Class Methods

init_simplify_dict() click to toggle source
# File lib/functions/fnc-trig.rb, line 321
def self.init_simplify_dict
  @simplify_dict = {
    CAS::Zero => (CAS::Pi / 2),
    CAS::One => CAS::Zero
  }
end

Public Instance Methods

call(f) click to toggle source

Call resolves the operation tree in a `Numeric` (if `Fixnum`) or `Float` (depends upon promotions). As input, it requires an hash with `CAS::Variable` or `CAS::Variable#name` as keys, and a `Numeric` as a value

* **argument**: `Hash` with feed dictionary
* **returns**: `Numeric`
# File lib/functions/fnc-trig.rb, line 298
def call(f)
  CAS::Help.assert(f, Hash)
  return Math::acos(@x.call(f))
end
diff(v) click to toggle source
# File lib/functions/fnc-trig.rb, line 283
def diff(v)
  if @x.depend? v
    return CAS.invert(@x.diff(v)/CAS.sqrt(CAS::One - CAS.pow(@x, CAS::Two)))
  else
    return CAS::Zero
  end
end
simplify() click to toggle source

Simplification callback. It simplify the subgraph of each node until all possible simplification are performed (thus the execution time is not deterministic).

* **returns**: `CAS::Op` simplified version
Calls superclass method CAS::Op#simplify
# File lib/functions/fnc-trig.rb, line 315
def simplify
  super
  return @x.x if @x.is_a? CAS::Cos
  return self.simplify_dictionary
end
to_code() click to toggle source

Convert expression to code (internal, for `CAS::Op#to_proc` method)

* **returns**: `String` that represent Ruby code to be parsed in `CAS::Op#to_proc`
# File lib/functions/fnc-trig.rb, line 331
def to_code
  "Math::acos(#{@x.to_code})"
end
to_s() click to toggle source

Convert expression to string

* **returns**: `String` to print on screen
# File lib/functions/fnc-trig.rb, line 306
def to_s
  "acos(#{@x})"
end