For bmx, add instances of :gap in initial plushy genomes according to :bmx-gap-probability

src/propeller/genome.cljc

@@ -6,11 +6,17 @@ They hold the genetic material for an `individual`. In the initial population, w
             [propeller.utils :as utils]))
 
 (defn make-random-plushy
-  "Creates and returns a new plushy made of random instructions and of a maximum size of max-initial-plushy-size."
-  [instructions max-initial-plushy-size]
-  (repeatedly
-   (rand-int max-initial-plushy-size)
-   #(utils/random-instruction instructions)))
+  "Creates and returns a new plushy made of random instructions."
+  [{:keys [instructions max-initial-plushy-size bmx? bmx-gap-probability]}]
+  (if bmx?
+    (repeatedly
+     (rand-int max-initial-plushy-size)
+     #(if (< (rand) bmx-gap-probability)
+        :gap
+        (utils/random-instruction instructions)))
+    (repeatedly
+     (rand-int max-initial-plushy-size)
+     #(utils/random-instruction instructions))))
 
 (defn plushy->push-internal
   [plushy argmap]

src/propeller/gp.cljc

@@ -50,8 +50,8 @@
 
 (defn gp
   "Main GP function"
-  [{:keys [population-size max-generations error-function instructions max-initial-plushy-size
-           solution-error-threshold ds-parent-rate ds-parent-gens dont-end ids-type downsample?]
+  [{:keys [population-size max-generations error-function solution-error-threshold 
+           ds-parent-rate ds-parent-gens dont-end ids-type downsample?]
     :or   {solution-error-threshold 0.0
            dont-end false
            ds-parent-rate 0
@@ -69,7 +69,7 @@
   (loop [generation 0
          evaluations 0
          population (utils/pmapallv
-                     (fn [_] {:plushy (genome/make-random-plushy instructions max-initial-plushy-size)})
+                     (fn [_] {:plushy (genome/make-random-plushy argmap)})
                      (range population-size)
                      argmap)
          indexed-training-data (if downsample?

src/propeller/session.cljc

@@ -55,7 +55,9 @@
 ;; and returning the Push program expressed by the genome:
 
 #_(genome/plushy->push
-    (genome/make-random-plushy (instructions/get-stack-instructions #{:float :integer :exec :boolean}) 20))
+    (genome/make-random-plushy 
+     {:instructions (instructions/get-stack-instructions #{:float :integer :exec :boolean}) 
+      :bmx-gap-probability 20}))
 
 ;; One way of running a genetic programming problem defined in the project
 ;; is to require the problem's namespace and then call `gp/gp` using the