class CAS::Cos
Representation for the `cos(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 226 def self.init_simplify_dict @simplify_dict = { CAS::Zero => CAS::One, CAS::Pi => CAS::One, CAS::Pi/2 => 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 203 def call(f) CAS::Help.assert(f, Hash) Math::cos(@x.call(f)) end
diff(v)
click to toggle source
Return the derivative of the `cos(x)` function using the chain rule. The input is a `CAS::Op` because it can handle derivatives with respect to functions.
“`
d
– cos(f(x)) = -f'(x) sin(fx) dx “`
* **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 188 def diff(v) if @x.depend? v return CAS.invert(@x.diff(v) * CAS.sin(@x)) 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 220 def simplify super return @x.x if @x.is_a? CAS::Acos 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 237 def to_code "Math::cos(#{@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 211 def to_s "cos(#{@x})" end