## Generated by Codox

# Propeller 0.3.2

# Adding Genetic Operators

In addition to the already-included genetic operators, you can add your own!

## Variation Genetic Operators

1. Go to `propeller.variation.cljc`
2. Define a genetic operator function
3. In `propeller.variation/new-individual`, add the new genetic operator in the `new-individual` function under the `case` call

    (defn new-individual
      "Returns a new individual produced by selection and variation of
      individuals in the population."
      [pop argmap]
      ...
         (case op
           ...

           :new-genetic-operator
           (-> (:plushy (selection/select-parent pop argmap))
               (new-genetic-operator ))
           ...
           :else
           (throw #?(:clj  (Exception. (str "No match in new-individual for " op))
                     :cljs (js/Error
                             (str "No match in new-individual for " op))))))})

4. When running a problem, specify the genetic operator in `:variation`. For example:

    lein run -m propeller.problems.simple-regression :variation "{:new-genetic-operator 1.0}"

## Selection Genetic Operators

1. Go to `propeller.selection.cljc`
2. Define a genetic operator function
3. In `propeller.selection.cljc`, add the new genetic operator in the `select-parent` function under the `case` call.

    (defn select-parent
      "Selects a parent from the population using the specified method."
      [pop argmap]
      (case (:parent-selection argmap)
        ...
        :new-genetic-operator (:new-genetic-operator )
        ...
        ))

4. When running a problem, specify the selection method in `:parent-selection`

For example:

    lein run -m propeller.problems.simple-regression :parent-selection :new-genetic-operator