class CAS::Tan

Representation for the `tan(x)` function. It is implemented as a `CAS::Op`.

Public Class Methods

init_simplify_dict() click to toggle source
# File lib/functions/fnc-trig.rb, line 384
def self.init_simplify_dict
  @simplify_dict = {
    CAS::Zero => CAS::Zero,
    CAS::Pi => CAS::Zero,
    CAS::Pi/2 => CAS::Infinity
  }
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 361
def call(f)
  CAS::Help.assert(f, Hash)
  Math::tan(@x.call(f))
end
diff(v) click to toggle source

Return the derivative of the `tan(x)` function using the chain rule. The input is a `CAS::Op` because it can handle derivatives with respect to functions. E.g.:

“`

d              f'(x)

– sin(f(x)) = ——- dx cos²(x) “`

* **argument**: `CAS::Op` object of the derivative
* **returns**: `CAS::Op` a derivated object, or `CAS::Zero` for constants
# File lib/functions/fnc-trig.rb, line 346
def diff(v)
  if @x.depend? v
    return @x.diff(v) * CAS.pow(CAS::One/CAS.cos(@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 378
def simplify
  super
  return @x.x if @x.is_a? CAS::Atan
  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 395
def to_code
  "Math::tan(#{@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 369
def to_s
  "tan(#{@x})"
end