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]]]
我有以下扁平的矢量:
(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)
我希望将展平的矢量转换为嵌套矢量,该矢量遵循与上面给出的嵌套矢量相同的结构。 Clojure或库中有核心功能吗?我有一些关于如何解决这个问题的想法,但是所有这些看起来都非常低效,而且这个操作将用于大向量。
非常感谢你。
答案 0 :(得分:8)
这是一个很有趣的问题,因为这是我认为使用拉链使事情更容易而不是更难的次数之一。想法是只做一个嵌套向量的vector-zip,来表示所需的结构,然后重复调用zip / next;每当我们到达一个叶子节点时,我们用输入序列中的下一个值替换它的值。
请注意,这假设嵌套结构中的项目与展平列表中的项目完全相同;如果不是这样的话,你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]]]