hierarchical

问题 I have to design an interface for hierarchical entity: interface HierarchicalEntity<T extends HierarchicalEntity<T>> { T getParent(); Stream<T> getAncestors(); } It's quite easy to implement default getAncestors() method in terms of getParent() in such a way that the former would return Stream of all the ancestors. Implementation example: default Stream<T> getAncestors() { Stream.Builder<T> parentsBuilder = Stream.builder(); T parent = getParent(); while (parent != null) { parentsBuilder.add

问题 I have DataFrame with MultiIndex columns that looks like this: # sample data col = pd.MultiIndex.from_arrays([['one', 'one', 'one', 'two', 'two', 'two'], ['a', 'b', 'c', 'a', 'b', 'c']]) data = pd.DataFrame(np.random.randn(4, 6), columns=col) data What is the proper, simple way of selecting only specific columns (e.g. ['a', 'c'] , not a range) from the second level? Currently I am doing it like this: import itertools tuples = [i for i in itertools.product(['one', 'two'], ['a', 'c'])] new

问题 Ok, I'm really stucked with this. I hope you can help me. I have my class, used to manage hierarchical data. The input is a plain array with the following structure (just an example): $list = array( (object) array('id' => 1, 'nombre' => 'Cámaras de fotos', 'parentId' => null), (object) array('id' => 2, 'nombre' => 'Lentes', 'parentId' => null), (object) array('id' => 3, 'nombre' => 'Zoom', 'parentId' => 2), (object) array('id' => 4, 'nombre' => 'SLR', 'parentId' => 1), (object) array('id' =>

问题 I googled for an answer to this for more than two weeks now. This usually means either I am blind or the idea is absurd. Anyways: In a middle-sized, quite flexible project I'm storing configuration data in a hierarchical structure in the like of this one: Configuration (collection) Audio (class) BaseDir (struct) PlayMode (enum) Input (class) CalibrateOnConnect (bool) KnownDevices (collection) ... (class) ... UseDevice (integer) Playlist (collection) FirstAudio (class) Path (string) Repeat

问题 I have many similar structure tables like this: CREATE TABLE [dbo].[tbl_Hierarchy]( [ID] [int] NOT NULL, [ParentID] [int] NOT NULL, [Text] [nvarchar](100) NOT NULL, --other field irrelevant to my question ) INSERT INTO dbo.tbl_Hierarchy VALUES(1,0,'parent1') INSERT INTO dbo.tbl_Hierarchy VALUES(2,0,'parent2') INSERT INTO tbl_Hierarchy VALUES(3,1,'child1') INSERT INTO tbl_Hierarchy VALUES(4,3,'grandchild1') INSERT INTO tbl_Hierarchy VALUES(5,2,'child2') Can you help me writing such as a stored

问题 I want to implement multilevel hierarchical edge bundling. By that I means I want to inculcate the behavior of radial tree like hierarchy and edge bundling like in Hierarchical Edge Bundling. The sample visualization is Radial Hierarchical bundling I know I need to use two d3.js layout for that. Also I need to change my json dataset accordingly. My sample dataset is only for normal d3.js HEB [ {"name": "A", "imports": ["A1", "A2", "A3"]}, {"name": "B", "imports": ["B1", "B2", "B3"]}, {"name":

问题 I tried to find some informations about connect by "engine". I found this post: Confusion with Oracle CONNECT BY User krokodilko answered and says: The analyze of the last query: select level from dual connect by rownum<10; I leave to you as a homework assignment. So i tried to do exactly as described to query Select rownum from dual connect by rownum < 3 And here's my "work": CREATE TABLE step1 AS SELECT 1 "LEVEL" FROM dual; SELECT * FROM step1; create table step2 as SELECT 2 "LEVEL" from

问题 I need to work on drawing a hierarchical tree structure (HV-Drawing – Binary Tree) with orthogonal lines(straight rectangular connecting lines) between root and children ( like the following: http://lab.kapit.fr/display/visualizationlayouts/Hierarchical+Tree+layout ). I want to know if there are any open source examples of the algorithm of drawing trees like that so that I can implement the same algorithm in actionscript. Thanks Palash 回答1: I did a C# version and put the code up on

问题 So I read this: http://mikehillyer.com/articles/managing-hierarchical-data-in-mysql/ And i'm using mysql and php What I need is script that convert only for one time the old data into data with the left/right values. I don't need to add/update things. The php data $in_array = array ( array( 'id' => 400, 'n' => 'Sub 1a', 's' => array ( array ( 'n' => 'Sub 1b', 'id' => 421, 's' => array ( array ( 'n' => 'Sub 1c', 'id' => 422, ) ) ) ) ), array( 'id' => 500, 'n' => 'Sub 2a', 's' => array ( array

问题 I have a dataframe of categories and amounts. Categories can be nested into sub categories an infinite levels using a colon separated string. I wish to sort it by descending amount. But in hierarchical type fashion like shown. How I need it sorted CATEGORY AMOUNT Transport 5000 Transport : Car 4900 Transport : Train 100 Household 1100 Household : Utilities 600 Household : Utilities : Water 400 Household : Utilities : Electric 200 Household : Cleaning 100 Household : Cleaning : Bathroom 75