class CAS::Abs
Absolute value of a function. It can be also implemented as a Piecewise
function.
Public Class Methods
init_simplify_dict()
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# File lib/functions/fnc-base.rb, line 516 def self.init_simplify_dict @simplify_dict = { CAS::Zero => CAS::Zero } end
Public Instance Methods
call(f)
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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. In this case it will call the `Fixnum#overloaded_plus`, that is the old plus function.
* **argument**: `Hash` with feed dictionary * **returns**: `Numeric`
# File lib/functions/fnc-base.rb, line 488 def call(f) CAS::Help.assert(f, Hash) s = (@x.call(f) >= 0 ? 1 : -1) return s * @x.call(f) end
diff(v)
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Performs the absolute value of a `CAS::Op`
“`
d
—- |f(x)| = f'(x) * (f(x) / |f(x)|)
dx
“`
* **argument**: `CAS::Op` argument of derivative * **returns**: `CAS::Op` derivative
# File lib/functions/fnc-base.rb, line 472 def diff(v) if @x.depend? v return @x.diff(v) * (@x/CAS.abs(@x)) else return CAS::Zero end end
simplify()
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Same as `CAS::Op`
Simplifcation engine supports:
* |-x| = x * |0| = 0 * **returns**: `CAS::Op` simplified version
Calls superclass method
CAS::Op#simplify
# File lib/functions/fnc-base.rb, line 510 def simplify super return CAS.abs(@x.x) if @x.is_a? CAS::Invert return self.simplify_dictionary end
to_code()
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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-base.rb, line 525 def to_code "(#{@x.to_code}).abs" end
to_s()
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Convert expression to string
* **returns**: `String` to print on screen
# File lib/functions/fnc-base.rb, line 498 def to_s "|#{@x}|" end