Mutation Problem - Clojure
- by Silanglaya Valerio
having trouble changing an element of my function represented as a list.
code for random function:
(defn makerandomtree-10
[pc maxdepth maxwidth fpx ppx]
(if-let [output
(if (and (< (rand) fpx) (> maxdepth 0))
(let [head (nth operations (rand-int (count operations)))
children (doall (loop[function (list)
width maxwidth]
(if (pos? width)
(recur (concat function
(list (makerandomtree-10 pc (dec maxdepth)
(+ 2 (rand-int (- maxwidth 1))) fpx ppx)))
(dec width))
function)))]
(concat (list head) children))
(if (and (< (rand) ppx) (>= pc 0))
(nth parameters (rand-int (count parameters)))
(rand-int 100)))]
output
))
I will provide also a mutation function, which is still not good enough. I need to be able to eval my statement, so the following is still insufficient.
(defn mutate-5
"chooses a node changes that"
[function pc maxwidth pchange]
(if (< (rand) pchange)
(let [output (makerandomtree-10 pc 3 maxwidth 0.5 0.6)]
(if (seq? output) output (list output)))
;mutate the children of root
;declare an empty accumulator list, with root as its head
(let [head (list (first function))
children (loop [acc(list)
walker (next function)] (println "----------") (println walker) (println "-----ACC-----") (println acc)
(if (not walker)
acc
(if (or (seq? (first function)) (contains? (set operations) (first function)))
(recur (concat acc (mutate-5 walker pc maxwidth pchange))
(next walker))
(if (< (rand) pchange)
(if (some (set parameters) walker)
(recur (concat acc (list (nth parameters (rand-int (count parameters)))))
(if (seq? walker) (next walker) nil))
(recur (concat acc (list (rand-int 100)))
(if (seq? walker) (next walker) nil)))
(recur acc (if (seq? walker) (next walker) nil))))
))]
(concat head (list children)))))
(side note: do you have any links/books for learning clojure?)