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不同的默认'initialCapacity'HashSet和LinkedHashSet(Different default 'initialCapacity' HashSet and LinkedHashSet)

 从集合构造HashSet和LinkedHashSet ， initialCapacity在默认实现中设置为不同的值。  
 HashSet的：  
public HashSet(Collection<? extends E> c) {
    map = new HashMap<>(Math.max((int) (c.size()/.75f) + 1, 16));
    addAll(c);
}
 
 LinkedHashSet：  
public LinkedHashSet(Collection<? extends E> c) {
    super(Math.max(2*c.size(), 11), .75f, true);
    addAll(c);
}
 
 我确信有一个完全有效的理由，但我看不到它。 

When constructing a HashSetand a LinkedHashSet from a collection, the initialCapacity is set to different values in the default implementation. 
HashSet: 
public HashSet(Collection<? extends E> c) {
    map = new HashMap<>(Math.max((int) (c.size()/.75f) + 1, 16));
    addAll(c);
}
 
LinkedHashSet: 
public LinkedHashSet(Collection<? extends E> c) {
    super(Math.max(2*c.size(), 11), .75f, true);
    addAll(c);
}
 
I'm sure there is a perfectly valid reason for this, but I fail to see it.

原文：https://stackoverflow.com/questions/41692230

更新时间：2023-05-14 19:05

最满意答案

 我认为你正在寻找：  
library(plyr)
ddply(diam,"color",
      function(x) {
          w <- wilcox.test(price~cut,data=x)
          with(w,data.frame(statistic,p.value))
      })
 
 （用t.test代替wilcox.test似乎也可以正常工作。）  
 结果：  
  color statistic      p.value
1     D  339753.5 4.232833e-24
2     E  591104.5 6.789386e-19
3     F  731767.5 2.955504e-11
4     G  950008.0 1.176953e-12
5     H  611157.5 2.055857e-17
6     I  213019.0 3.299365e-04
7     J   56870.0 2.364026e-01

I think you're looking for: 
library(plyr)
ddply(diam,"color",
      function(x) {
          w <- wilcox.test(price~cut,data=x)
          with(w,data.frame(statistic,p.value))
      })
 
(Substituting t.test for wilcox.test seems to work fine too.) 
results: 
  color statistic      p.value
1     D  339753.5 4.232833e-24
2     E  591104.5 6.789386e-19
3     F  731767.5 2.955504e-11
4     G  950008.0 1.176953e-12
5     H  611157.5 2.055857e-17
6     I  213019.0 3.299365e-04
7     J   56870.0 2.364026e-01

不同的默认'initialCapacity'HashSet和LinkedHashSet(Different default 'initialCapacity' HashSet and LinkedHashSet)

最满意答案

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