treemap

I have a package which uses the tmPlot function from treemap , but when I try to use the function, it throws an error that one of its dependencies isn't loaded: Error in tmPlot(data, index = index, vSize = vSize) : could not find function "brewer.pal" The dependency is installed and in the namespace. This question has a little bit of setup, being a package problem, but I've tried to make it as minimal as possible: Ensure you have treemap (and all its dependencies) installed. I've made a directory called 'anRpackage'. Inside it is a folder ('R') and a DESCRIPTION file with the following text:

Queue 什么是队列 队列是数据结构中比较重要的一种类型，它支持 FIFO，尾部添加、头部删除（先进队列的元素先出队列），跟我们生活中的排队类似。 队列的种类 单队列 （单队列就是常见的队列, 每次添加元素时，都是添加到队尾，存在“假溢出”的问题也就是明明有位置却不能添加的情况） 循环队列 （避免了“假溢出”的问题） Java 集合框架中的队列 Queue Java 集合中的 Queue 继承自 Collection 接口 ，Deque, LinkedList, PriorityQueue, BlockingQueue 等类都实现了它。 Queue 用来存放 等待处理元素 的集合，这种场景一般用于缓冲、并发访问。 除了继承 Collection 接口的一些方法，Queue 还添加了额外的 添加、删除、查询操作。 推荐文章 Java 集合深入理解（9）：Queue 队列 Set 什么是 Set Set 继承于 Collection 接口，是一个不允许出现重复元素，并且无序的集合，主要 HashSet 和 TreeSet 两大实现类。 在判断重复元素的时候，Set 集合会调用 hashCode()和 equal()方法来实现。 补充：有序集合与无序集合说明 有序集合：集合里的元素可以根据 key 或 index 访问 (List、Map) 无序集合：集合里的元素只能遍历。（Set）

I am migrating my Java code base to pure Scala and I am stuck on this one piece of code . I have an implementation of an IntervalMap i.e. a data structures that let's you efficiently map ranges [from,to] to values where the set , delete and get operations are all O(log n) (slightly different from an IntervalTree or a SegmentTree). This code uses Java's java.util.TreeMaps and while migrating to Scala, I ran into 2 big issues: Scala has no mutable.TreeMap - I decided to go around it by using mutable.TreeSet (oddly Scala has mutable.TreeSet but no mutable.TreeMap ) for storing the keys and

重识java-LinkedHashMap 使用场景 如果需要使用的Map中的 key无序 ，选择 HashMap ；如果要求 key有序 ，则选择 TreeMap 。 但是选择TreeMap就会有 性能问题 ，因为TreeMap的get操作的时间复杂度是 O(log(n)) 的，相比于HashMap的 O(1) 还是差不少的， LinkedHashMap 的出现就是为了平衡这些因素，使得 能够以 O(1)时间复杂度增加查找元素，又能够保证key的有序性 此外，LinkedHashMap提供了两种key的顺序： 访问顺序（access order）。非常实用，可以使用这种顺序实现 LRU（Least Recently Used） 缓存 插入顺序（insertion orde）。同一key的多次插入，并不会影响其顺序 源代码解读 类声明 public class LinkedHashMap<K,V> extends HashMap<K,V> implements Map<K,V> 继承自HashMap，此处实现Map接口，用来表明该类是Map系的类。 功能和特点 LinkedHashMap 中采用的这种环型双向链表. key有序，并且get时间复杂度为O(1)。 有两种记录顺序的方式，一种是访问顺序，一种是key插入的顺序。 常量 final boolean accessOrder;/

I would like to create a TreeMap , using pictures to fill out the treemap rectangles. I can assume that all the pictures have the same width and height (i.e. the aspect ratio). Thus, I need a treemapping algorithm to create the rectangles with a given ratio, do I will be able to put the pictures there (and perhaps scale the pictures if I need). Could you recommend one ? In general, a solution is not possible - Albin Sunnanbo has provided a proof by counterexample. Assuming your bounding rectangle has the same aspect ratio as your target rectangles, you might be able to get a good-enough

I have some hierarchical data, e.g., > library(dplyr) > df <- data_frame(id = 1:6, parent_id = c(NA, 1, 1, 2, 2, 5)) > df Source: local data frame [6 x 2] id parent_id (int) (dbl) 1 1 NA 2 2 1 3 3 1 4 4 2 5 5 2 6 6 5 I would like to plot the tree in a "top down" view through a circle packing plot: http://bl.ocks.org/mbostock/4063530 The above link is for a d3 library. Is there an equivalent that allows me to make such a plot in ggplot2? (I want this plot in a shiny app, which does support d3, but I haven't used d3 before and am unsure about the learning curve. If d3 is the obvious choice, I

Does anyone know the time complexity of the operations of TreeMap like - subMap, headMap. tailMap. The time complexity of operations like get, put is O(logn). But the javadoc doesnt say much about the complexity for the above operations. The worst case complexity I can thinks of O(n) since it will go through the entire list if the set includes the last element. Can we confirm it? For those questions having the source code on hand is very useful as with sufficient IDE support you can simply browse through the implementation. When looking at the source code of TreeMap it can be seen, that all

常见的map类有： HashMap, ConcurrentHashMap (Jdk1.8) , LinkedHashMap, TreeMap, Hashtable。 其中我们最常用的莫过于HashMap, 和并发情况下使用的ConcurrentHashMap了，它们的主要区别就在于HashMap是非线程安全的，而ConcurrentHashMap是线程安全的。 并发情况下可以使用HashTable和ConcurrentHashMap ,它们的区别在于： >* ConcurrentHashMap的hash计算公式：(key.hascode()^ (key.hascode()>>> 16)) & 0x7FFFFFFF, 而 HashTable的hash计算公式：key.hascode() & 0x7FFFFFFF 2.HashTable存储方式都是链表+数组，数组里面放的是当前hash的第一个数据，链表里面放的是hash冲突的数据 ，ConcurrentHashMap是数组+链表+红黑树. 线程安全的保证： HashTable是在每一个操作方法上都加上synchronized关键字来达到线程安全的目的，而ConcurrentHashMap则是通过CAS算法（CompareAndSwap）来保证线程安全。 ConcurrentHashMap 放弃了分段锁，而使用了Nodo锁