vector - Clojure:将嵌套向量格式应用于展平向量

Question

例如，我有以下嵌套向量:

[[[0.582198689235419 -0.34713183143727 0.4685311493624731]
  [-0.38928013774079284 -0.5901700383677557 -0.37573234072157]
  [0.6716356761877877 -0.19645167952721243 -0.5700686091940252]]
 [[0.0027162308840597005 -0.4483592764429284 -0.4766278022217257 -0.2724018313051576]
  [-0.2765881229144672 -0.8030656496255356 -0.16159395457031567 -0.27432324260043084]
  [-0.6154630466545907 -0.60573539482247 0.4417814561800192 -0.5559788990464504]
  [0.6194560094536031 -0.3663074359460578 -0.5704311251195602 0.7194827876969362]]]

我有以下扁平向量:

(0.5366343712173423
 -0.816449781850872
 -0.16066485785704843
 0.9816561233924161
 -0.09646744313584676
 -0.2619662625757997
 -0.9946004265996822
 -0.14096299956754854
 0.579260850612288
 -0.827601452607939
 -0.24934665032374648
 -0.42272393175707873
 0.11239245249400165
 -0.29878238708035043
 -0.61522274672097
 0.8298721730401472
 0.5016214138116059
 0.11633537727916243
 -0.0631891708267196
 -0.26569217599364303
 0.20900664784109668
 0.2005869506108401
 -0.2658279978034501
 0.3383997403318165
 -0.09353513546647907)

我希望将展平向量转换为嵌套向量，该向量遵循与上面所示的嵌套向量相同的结构。 Clojure 或库中是否有核心函数可以执行此操作？我对如何解决这个问题有一些想法，但所有这些想法似乎都非常非常低效，并且此操作将与大向量一起使用。

提前非常感谢您。

Answer 1

这是一个有趣的问题，因为这是我认为使用 zipper 使事情变得更容易而不是更困难的极少数情况之一。这个想法是只对嵌套向量进行向量压缩，以表示所需的结构，并对其重复调用 zip/next ；每当我们到达一个叶子节点时，我们都会用输入序列中的下一个节点替换它的值。

请注意，这假设嵌套结构中的项目数与展平列表中的项目数完全相同；如果情况并非如此，您可能会收到某种错误，谁知道呢。

(require '[clojure.zip :as z])

(defn replace-values [structure values]
  (loop [z (z/vector-zip structure)
         values (seq values)]
    (cond (not values) (z/root z)
          (z/branch? z) (recur (z/next z) values)
          :else (recur (-> z
                           (z/replace (first values))
                           (z/next))
                       (next values)))))

user> (replace-values '[[[0.582198689235419 -0.34713183143727 0.4685311493624731]
                         [-0.38928013774079284 -0.5901700383677557 -0.37573234072157]
                         [0.6716356761877877 -0.19645167952721243 -0.5700686091940252]]
                        [[0.0027162308840597005 -0.4483592764429284 -0.4766278022217257 -0.2724018313051576]
                         [-0.2765881229144672 -0.8030656496255356 -0.16159395457031567 -0.27432324260043084]
                         [-0.6154630466545907 -0.60573539482247 0.4417814561800192 -0.5559788990464504]
                         [0.6194560094536031 -0.3663074359460578 -0.5704311251195602 0.7194827876969362]]]
                      '(0.5366343712173423
                        -0.816449781850872
                        -0.16066485785704843
                        0.9816561233924161
                        -0.09646744313584676
                        -0.2619662625757997
                        -0.9946004265996822
                        -0.14096299956754854
                        0.579260850612288
                        -0.827601452607939
                        -0.24934665032374648
                        -0.42272393175707873
                        0.11239245249400165
                        -0.29878238708035043
                        -0.61522274672097
                        0.8298721730401472
                        0.5016214138116059
                        0.11633537727916243
                        -0.0631891708267196
                        -0.26569217599364303
                        0.20900664784109668
                        0.2005869506108401
                        -0.2658279978034501
                        0.3383997403318165
                        -0.09353513546647907))

[[[0.5366343712173423 -0.816449781850872 -0.16066485785704843]
  [0.9816561233924161 -0.09646744313584676 -0.2619662625757997]
  [-0.9946004265996822 -0.14096299956754854 0.579260850612288]]
 [[-0.827601452607939 -0.24934665032374648 -0.42272393175707873 0.11239245249400165]
  [-0.29878238708035043 -0.61522274672097 0.8298721730401472 0.5016214138116059]
  [0.11633537727916243 -0.0631891708267196 -0.26569217599364303 0.20900664784109668]
  [0.2005869506108401 -0.2658279978034501 0.3383997403318165 -0.09353513546647907]]]