clojure.lang.LazySeq 无法转换为 class clojure.lang.Associative
clojure.lang.LazySeq cannot be cast to class clojure.lang.Associative
我是 Clojure 的新手，我试图实现一个遗传算法。因此，我遇到了一个问题，实现不断抛出以下错误：
class clojure.lang.LazySeq cannot be cast to class clojure.lang.Associative (clojure.lang.LazySeq and clojure.lang.Associative are in unnamed module
of loader 'app')
需要说明的是，每个函数都是在REPL中单独测试的，returns结果是正确的，但是把它们放在一起后，就报错了，我不明白，因为它似乎不指定行号。
clojure 的版本来自 master 分支，使用 maven 构建，Windows。
完整代码：
(ns ga)
(defn new-individual
[genome-length]
{:genome (vec (repeatedly genome-length #(rand-int 2))) :fitness 0}
)
(defn fitness-function
[genome, target]
(Math/abs (- (reduce + genome) target))
)
(defn calculate-fitness
[population, target]
(defn fitness-function-helper
[individual, target]
(assoc individual :fitness (fitness-function (individual :genome) target))
)
(map (fn [individual] (#(fitness-function-helper individual target))) population)
)
(defn crossover
[first-individual, second-individual, crossover-rate, target]
(let [new-genome (map (fn [i1,i2] (let [crossover-probability (rand)]
(cond
(<= crossover-probability crossover-rate) i1
:else i2
)
)
)
(first-individual :genome) (second-individual :genome)
)]
{:genome new-genome :fitness (fitness-function new-genome target)}
)
)
(defn mutate
[individual, genome-length, target]
(let [new-genome (assoc (individual :genome) (rand-int genome-length) (rand-int 2))]
{:genome new-genome :fitness (fitness-function new-genome target)}
)
)
(defn better
[i1 i2]
(< (i1 :fitness) (i2 :fitness)))
(defn tournament-selection
[population, population-size, steps, tournament-size, new-population, target]
(if (< steps tournament-size)
(recur population population-size (inc steps) tournament-size (conj new-population (nth population ((comp rand-int -) population-size 2))) target
)
;(println new-population)
(first (sort better (calculate-fitness new-population target)))
)
)
(defn new-generation [population, population-size, crossover-rate, target, tournament-size]
(loop [steps 0 new-population ()]
(if (< steps population-size)
(let [i1 (tournament-selection population population-size 0 tournament-size () target)]
(let [i2 (tournament-selection population population-size 0 tournament-size () target)]
(let [offs (crossover i1 i2 crossover-rate target)]
(recur (inc steps) (conj new-population offs))
)
)
)
new-population
)
)
)
(defn new-mutated-generation [population, population-size, genome-length, target]
(loop [steps 0 new-population ()]
(if (< steps population-size)
(recur (inc steps) (conj new-population (mutate (nth population steps) genome-length target)))
new-population
)
)
)
(defn evolve [population-size, genome-length, target]
(let [population (calculate-fitness (repeatedly population-size #(new-individual genome-length)) target)]
(let [offsprings (new-generation population population-size 0.5 target 5)]
(println (new-mutated-generation offsprings population-size genome-length target))
)
)
)
(evolve 10 5 5)
函数mutate发生错误。它有这个来源：
(defn mutate
[individual, genome-length, target]
(let [new-genome (assoc (individual :genome) (rand-int genome-length) (rand-int 2))]
{:genome new-genome :fitness (fitness-function new-genome target)}))
在一个步骤中，您使用这些参数调用它：{:genome (0 1 1 1 1), :fitness 1} 5 5（基因组可以有不同的值，但它始终是数字序列）。
(individual :genome) returns (0 1 1 1 1) （序列）然后你使用了 assoc，它是哈希映射或向量的函数。
Genome一开始是向量，但在crossover函数中被转换成序列-这里用mapv代替map：
(defn crossover
[first-individual, second-individual, crossover-rate, target]
(let [new-genome (mapv (fn [i1, i2] (let [crossover-probability (rand)]
(if (<= crossover-probability crossover-rate) i1 i2)))
(first-individual :genome) (second-individual :genome))]
{:genome new-genome :fitness (fitness-function new-genome target)}))
顺便说一下，定义末尾的所有括号都在同一行。
堆栈跟踪显示有问题的代码是行
(let [new-genome (assoc (vec (individual :genome)) (rand-int genome-length) (rand-int 2))]
更具体地说，是对 assoc 的调用。如果我们通过在上面插入以下行来编辑代码：
(println "Individual: " (individual :genome) ", " (class (individual :genome)))
它打印出来
Individual: (0 1 1 0 1) , clojure.lang.LazySeq
问题是 assoc 不能与惰性序列 (clojure.lang.LazySeq) 一起使用，因为它没有实现 clojure.lang.Associative interface which is needed by assoc.
这个惰性序列是通过在这一行调用 map 构造的：
(let [new-genome (map (fn [i1,i2] (let [crossover-probability (rand)]
(let [new-genome (mapv (fn [i1,i2] (let [crossover-probability (rand)]
代码将起作用。
我是 Clojure 的新手，我试图实现一个遗传算法。因此，我遇到了一个问题，实现不断抛出以下错误：
class clojure.lang.LazySeq cannot be cast to class clojure.lang.Associative (clojure.lang.LazySeq and clojure.lang.Associative are in unnamed module
of loader 'app')
需要说明的是，每个函数都是在REPL中单独测试的，returns结果是正确的，但是把它们放在一起后，就报错了，我不明白，因为它似乎不指定行号。
clojure 的版本来自 master 分支，使用 maven 构建，Windows。
完整代码：
(ns ga)
(defn new-individual
[genome-length]
{:genome (vec (repeatedly genome-length #(rand-int 2))) :fitness 0}
)
(defn fitness-function
[genome, target]
(Math/abs (- (reduce + genome) target))
)
(defn calculate-fitness
[population, target]
(defn fitness-function-helper
[individual, target]
(assoc individual :fitness (fitness-function (individual :genome) target))
)
(map (fn [individual] (#(fitness-function-helper individual target))) population)
)
(defn crossover
[first-individual, second-individual, crossover-rate, target]
(let [new-genome (map (fn [i1,i2] (let [crossover-probability (rand)]
(cond
(<= crossover-probability crossover-rate) i1
:else i2
)
)
)
(first-individual :genome) (second-individual :genome)
)]
{:genome new-genome :fitness (fitness-function new-genome target)}
)
)
(defn mutate
[individual, genome-length, target]
(let [new-genome (assoc (individual :genome) (rand-int genome-length) (rand-int 2))]
{:genome new-genome :fitness (fitness-function new-genome target)}
)
)
(defn better
[i1 i2]
(< (i1 :fitness) (i2 :fitness)))
(defn tournament-selection
[population, population-size, steps, tournament-size, new-population, target]
(if (< steps tournament-size)
(recur population population-size (inc steps) tournament-size (conj new-population (nth population ((comp rand-int -) population-size 2))) target
)
;(println new-population)
(first (sort better (calculate-fitness new-population target)))
)
)
(defn new-generation [population, population-size, crossover-rate, target, tournament-size]
(loop [steps 0 new-population ()]
(if (< steps population-size)
(let [i1 (tournament-selection population population-size 0 tournament-size () target)]
(let [i2 (tournament-selection population population-size 0 tournament-size () target)]
(let [offs (crossover i1 i2 crossover-rate target)]
(recur (inc steps) (conj new-population offs))
)
)
)
new-population
)
)
)
(defn new-mutated-generation [population, population-size, genome-length, target]
(loop [steps 0 new-population ()]
(if (< steps population-size)
(recur (inc steps) (conj new-population (mutate (nth population steps) genome-length target)))
new-population
)
)
)
(defn evolve [population-size, genome-length, target]
(let [population (calculate-fitness (repeatedly population-size #(new-individual genome-length)) target)]
(let [offsprings (new-generation population population-size 0.5 target 5)]
(println (new-mutated-generation offsprings population-size genome-length target))
)
)
)
(evolve 10 5 5)
函数mutate发生错误。它有这个来源：
(defn mutate
[individual, genome-length, target]
(let [new-genome (assoc (individual :genome) (rand-int genome-length) (rand-int 2))]
{:genome new-genome :fitness (fitness-function new-genome target)}))
在一个步骤中，您使用这些参数调用它：{:genome (0 1 1 1 1), :fitness 1} 5 5（基因组可以有不同的值，但它始终是数字序列）。
(individual :genome) returns (0 1 1 1 1) （序列）然后你使用了 assoc，它是哈希映射或向量的函数。
Genome一开始是向量，但在crossover函数中被转换成序列-这里用mapv代替map：
(defn crossover
[first-individual, second-individual, crossover-rate, target]
(let [new-genome (mapv (fn [i1, i2] (let [crossover-probability (rand)]
(if (<= crossover-probability crossover-rate) i1 i2)))
(first-individual :genome) (second-individual :genome))]
{:genome new-genome :fitness (fitness-function new-genome target)}))
顺便说一下，定义末尾的所有括号都在同一行。
堆栈跟踪显示有问题的代码是行
(let [new-genome (assoc (vec (individual :genome)) (rand-int genome-length) (rand-int 2))]
更具体地说，是对 assoc 的调用。如果我们通过在上面插入以下行来编辑代码：
(println "Individual: " (individual :genome) ", " (class (individual :genome)))
它打印出来
Individual: (0 1 1 0 1) , clojure.lang.LazySeq
问题是 assoc 不能与惰性序列 (clojure.lang.LazySeq) 一起使用，因为它没有实现 clojure.lang.Associative interface which is needed by assoc.
这个惰性序列是通过在这一行调用 map 构造的：
(let [new-genome (map (fn [i1,i2] (let [crossover-probability (rand)]
(let [new-genome (mapv (fn [i1,i2] (let [crossover-probability (rand)]
代码将起作用。