Search Results

Search found 1139 results on 46 pages for 'hierarchical trees'.

Page 4/46 | < Previous Page | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >

• Solving the context menu problem with drag and drop in trees

  - by Frank Nimphius

  Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} The following drag-and-drop problem has been reported on OTN: An ADF Faces tree component is configured with a af:collectionDropTarget tag to handle drop events. The same tree component also has a context menu defined that is shown when users select the tree with the right mouse button. The problem now was - and I could reproduce this - that the context menu stopped working after the first time the tree handled a drop event. The drag and drop use case is to associate employees from a table to a department in the tree using drag and drop. The drop handler code in the managed bean looked up the tree node that received the drop event to determine the department ID to assign to the employee. For this code similar to the one shown below was used List dropRowKey = (List) dropEvent.getDropSite(); //if no dropsite then drop area was not a data area if(dropRowKey == null){    return DnDAction.NONE; }                tree.setRowKey(dropRowKey); JUCtrlHierNodeBinding dropNode = (JUCtrlHierNodeBinding) tree.getRowData(); Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} So what happens in this code? The drop event contains the dropSite reference, which is the row key of the tree node that received the drop event. The code then sets the key to the tree in a call to getRowDate() returns the node information for the drop target (the department). This however causes the tree state to go out of synch with its model (ADF tree binding), which is known to cause issues. In this use case the issue caused by this is that the context menu no longer shows up. To fix the problem, the code needs to be changes to read the current row key from the key, then perform the drop operation and at the end set the origin (or model) row key back //memorize current row key Object currentRowKey = tree.getRowKey();        List dropRowKey = (List) dropEvent.getDropSite(); //if no dropsite then drop area was not a data area if(dropRowKey == null){   return DnDAction.NONE;   }              tree.setRowKey(dropRowKey); JUCtrlHierNodeBinding dropNode = (JUCtrlHierNodeBinding) tree.getRowData(); ... do your stuff here .... //set current row key back tree.setRowKey(currentRowKey); AdfFacesContext.getCurrentInstance().addPartialTarget(tree); Node the code line that sets the row key back to its original value.

  Read the article

• What are the Options for Storing Hierarchical Data in a Relational Database?

  - by orangepips

  Good Overviews One more Nested Intervals vs. Adjacency List comparison: the best comparison of Adjacency List, Materialized Path, Nested Set and Nested Interval I've found. Models for hierarchical data: slides with good explanations of tradeoffs and example usage Representing hierarchies in MySQL: very good overview of Nested Set in particular Hierarchical data in RDBMSs: most comprehensive and well organized set of links I've seen, but not much in the way on explanation Options Ones I am aware of and general features: Adjacency List: Columns: ID, ParentID Easy to implement. Cheap node moves, inserts, and deletes. Expensive to find level (can store as a computed column), ancestry & descendants (Bridge Hierarchy combined with level column can solve), path (Lineage Column can solve). Use Common Table Expressions in those databases that support them to traverse. Nested Set (a.k.a Modified Preorder Tree Traversal) First described by Joe Celko - covered in depth in his book Trees and Hierarchies in SQL for Smarties Columns: Left, Right Cheap level, ancestry, descendants Compared to Adjacency List, moves, inserts, deletes more expensive. Requires a specific sort order (e.g. created). So sorting all descendants in a different order requires additional work. Nested Intervals Combination of Nested Sets and Materialized Path where left/right columns are floating point decimals instead of integers and encode the path information. Bridge Table (a.k.a. Closure Table: some good ideas about how to use triggers for maintaining this approach) Columns: ancestor, descendant Stands apart from table it describes. Can include some nodes in more than one hierarchy. Cheap ancestry and descendants (albeit not in what order) For complete knowledge of a hierarchy needs to be combined with another option. Flat Table A modification of the Adjacency List that adds a Level and Rank (e.g. ordering) column to each record. Expensive move and delete Cheap ancestry and descendants Good Use: threaded discussion - forums / blog comments Lineage Column (a.k.a. Materialized Path, Path Enumeration) Column: lineage (e.g. /parent/child/grandchild/etc...) Limit to how deep the hierarchy can be. Descendants cheap (e.g. LEFT(lineage, #) = '/enumerated/path') Ancestry tricky (database specific queries) Database Specific Notes MySQL Use session variables for Adjacency List Oracle Use CONNECT BY to traverse Adjacency Lists PostgreSQL ltree datatype for Materialized Path SQL Server General summary 2008 offers HierarchyId data type appears to help with Lineage Column approach and expand the depth that can be represented.

  Read the article

• is there a database that can easily digest hierarchical data besides XML?

  - by Luke101

  It is very difficult for me to design the database because it requires a lot of recursion. I really can't use XML because it is just not practical for scalability and the amount of data I need to store. Do you guys know of a database that can be used to store hierarchical data?

  Read the article

• What would be the time complexity of counting the number of all structurally different binary trees?

  - by ktslwy

  Using the method presented here: http://cslibrary.stanford.edu/110/BinaryTrees.html#java 12. countTrees() Solution (Java) /** For the key values 1...numKeys, how many structurally unique binary search trees are possible that store those keys? Strategy: consider that each value could be the root. Recursively find the size of the left and right subtrees. */ public static int countTrees(int numKeys) { if (numKeys <=1) { return(1); } else { // there will be one value at the root, with whatever remains // on the left and right each forming their own subtrees. // Iterate through all the values that could be the root... int sum = 0; int left, right, root; for (root=1; root<=numKeys; root++) { left = countTrees(root-1); right = countTrees(numKeys - root); // number of possible trees with this root == left*right sum += left*right; } return(sum); } } I have a sense that it might be n(n-1)(n-2)...1, i.e. n!

  Read the article

• Application of hashing and trees

  - by Bhargava dns

  Both hashing and trees can be used for searching of the elements.But where exactly hashing is used and trees are used.Give some real life examples binary trees are used.

  Read the article

• Are interval, segment, fenwick trees the same?

  - by Luiguis

  Today i listened a lecture about fenwick trees (binary indexed trees) and the teacher says than this tree is a generalization of interval and segment trees, but my implementations of this three data structures are different. Is this afirmation true? and Why?

  Read the article

• Hierarchical animations in DirectX and handling seperate animations on the same mesh?

  - by meds

  I have a hierarchical animated model in DirectX which loads and animates based on the following DirectX sample: http://msdn.microsoft.com/en-us/library/ee418677%28VS.85%29.aspx As good as the sample is it does not really go into some of the details of animation that I'd like. For example, if I have a mesh which has a running animation and a throwing animation as seperate animation sets how can I get the throwing animation to occur for bones above the hip and the walking animation to occur for bones underneath the hip? Also if I wanted to for example have the person lean left or right would I simply have to find the bone for the hip and multiplay a rotation matrix by its matrix? In this case I think the matrix is m_amxBoneOffsets?

  Read the article

• Is it Possible to Use Constraints on Hierarchical Data in a Self-Referential Table?

  - by pbarney

  Suppose you have the following table, intended to represent hierarchical data: +--------+-------------+ | Field | Type | +--------+-------------+ | id | int(10) | | parent | int(10) | | name | varchar(45) | +--------+-------------+ The table is self-referential in that the parent_id refers to id. So you might have the following data: +----+--------+---------------+ | id | parent | name | +----+--------+---------------+ | 1 | 0 | fruit | | 2 | 0 | vegetable | | 3 | 1 | apple | | 4 | 1 | orange | | 5 | 3 | red delicious | | 6 | 3 | granny smith | | 7 | 3 | gala | +----+--------+---------------+ Using MySQL, I am trying to impose a (self-referential) foreign key constraint upon the data to cascade on update and prevent deletion of a record if it has any "children." So I used the following: CREATE TABLE `test`.`fruit` ( `id` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT, `parent` INT(10) UNSIGNED, `name` VARCHAR(45) NOT NULL, PRIMARY KEY (`id`), CONSTRAINT `fk_parent` FOREIGN KEY (`parent`) REFERENCES `fruit` (`id`) ON UPDATE CASCADE ON DELETE RESTRICT ) ENGINE = InnoDB; From what I understand, this should fit my requirements. (And parent must default to null to allow insertions, correct?) The problem is, if I change the id of a record, it will not cascade: Cannot delete or update a parent row: a foreign key constraint fails (`test`.`fruit`, CONSTRAINT `fk_parent` FOREIGN KEY (`parent`) REFERENCES `fruit` (`id`) ON UPDATE CASCADE) What am I missing? Feel free to correct me if my terminology is screwed up... I'm new to constraints.

  Read the article

• design patterns for hierarchical structures

  - by JLBarros

  Anyone knows some design patterns for hierarchical structures? For example, to manage inventory categories, accounting chart of accounts, divisions of human resources, etc.. Thank you very much in advance EDIT: Thanks for your interest. I am looking for a better way of dealing with hierarchical items to which they should apply operations depending on the level of hierarchy. I have been studying the patterns by Martin Fowler, for example Accounting, but I wonder if there are other more generic. The problem is that operations apply to the items must be possible to change even at run time and may depend on other external variables. I thought of a kind of strategy pattern but would like to combine it with the fact that it is a hierarchical scheme. I would appreciate any reference to hierarchical patterns and you'll take care of them in depth.

  Read the article

• Hierarchical View/ViewModel/Presenters in MVPVM

  - by Brian Flynn

  I've been working with MVVM for a while, but I've recently started using MVPVM and I want to know how to create hierarchial View/ViewModel/Presenter app using this pattern. In MVVM I would typically build my application using a hierarchy of Views and corresponding ViewModels e.g. I might define 3 views as follows: The View Models for these views would be as follows: public class AViewModel { public string Text { get { return "This is A!"; } } public object Child1 { get; set; } public object Child2 { get; set; } } public class BViewModel { public string Text { get { return "This is B!"; } } } public class CViewModel { public string Text { get { return "This is C!"; } } } In would then have some data templates to say that BViewModel and CViewModel should be presented using View B and View C: <DataTemplate DataType="{StaticResource local:BViewModel}"> <local:BView/> </DataTemplate> <DataTemplate DataType="{StaticResource local:CViewModel}"> <local:CView/> </DataTemplate> The final step would be to put some code in AViewModel that would assign values to Child1 and Child2: public AViewModel() { this.Child1 = new AViewModel(); this.Child2 = new BViewModel(); } The result of all this would be a screen that looks something like: Doing this in MVPVM would be fairly simple - simply moving the code in AViewModel's constructor to APresenter: public class APresenter { .... public void WireUp() { ViewModel.Child1 = new BViewModel(); ViewModel.Child2 = new CViewModel(); } } But If I want to have business logic for BViewModel and CViewModel I would need to have a BPresenter and a CPresenter - the problem is, Im not sure where the best place to put these are. I could store references to the presenter for AViewModel.Child1 and AViewModel.Child2 in APresenter i.e.: public class APresenter : IPresenter { private IPresenter child1Presenter; private IPresenter child2Presenter; public void WireUp() { child1Presenter = new BPresenter(); child1Presenter.WireUp(); child2Presenter = new CPresenter(); child2Presenter.WireUp(); ViewModel.Child1 = child1Presenter.ViewModel; ViewModel.Child2 = child2Presenter.ViewModel; } } But this solution seems inelegant compared to the MVVM approach. I have to keep track of both the presenter and the view model and ensure they stay in sync. If, for example, I wanted a button on View A, which, when clicked swapped the View's in Child1 and Child2, I might have a command that did the following: var temp = ViewModel.Child1; ViewModel.Child1 = ViewModel.Child2; ViewModel.Child2 = temp; This would work as far as swapping the view's on screen (assuming the correct Property Change notification code is in place), but now my APresenter.child1Presenter is pointing to the presenter for AViewModel.Child2, and APresenter.child2Presenter is pointing to the presenter for AViewModel.Child1. If something accesses APresenter.child1Presenter, any changes will actually happen to AViewModel.Child2. I can imagine this leading to all sorts of debugging fun. I know that I may be misunderstanding the pattern, and if this is the case a clarification of what Im doing wrong would be appreciated.

  Read the article

• How to display a hierarchical skill tree in php

  - by user3587554

  If I have skill data set up in a tree format (where earlier skills are prerequisites for later ones), how would I display it as a tree, using php? The parent would be on top and have 3 children. Each of these children can then have one more child so its parent would be directly above it. I'm having trouble figuring out how to add the root element in the middle of the top div, and the child of the children below each child of the root. I'm not looking for code, but an explanation of how to do it. My data in array form is this: Data: Array ( [1] => Array ( [id] => 1 [title] => Jutsu [description] => Skill that makes you awesomer at using ninjutsu [tiers] => 1 [prereq] => [image] => images/skills/jutsu.png [children] => Array ( [2] => Array ( [id] => 2 [title] => fireball [description] => Increase your damage with fire jutsu and weapons [tiers] => 5 [prereq] => 1 [image] => images/skills/fireball.png [children] => Array ( [5] => Array ( [id] => 5 [title] => pin point [description] => Increases jutsu accuracy [tiers] => 5 [prereq] => 2 [image] => images/skills/pinpoint.png ) ) ) [3] => Array ( [id] => 3 [title] => synergy [description] => Reduce the amount of chakra needed to use ninjutsu [tiers] => 1 [prereq] => 1 [image] => images/skills/synergy.png ) [4] => Array ( [id] => 4 [title] => ebb & flow [description] => Increase the damage of water jutsu, water weapons, and reduce the damage of jutsu and weapons that use water element [tiers] => 5 [prereq] => 1 [image] => images/skills/ebbandflow.png [children] => Array ( [6] => Array ( [id] => 6 [title] => IQ [description] => Decrease the time it takes to learn a jutsu [tiers] => 5 [prereq] => 4 [image] => images/skills/iq.png ) ) ) ) ) ) An example would be this demo image minus the hover stuff.

  Read the article

• Storing hierarchical template into a database

  - by pduersteler

  If this title is ambiguous, feel free to change it, I don't know how to put this in a one-liner. Example: Let's assume you have a html template which contains some custom tags, like <text_field />. We now create a page based on a template containing more of those custom tags. When a user wants to edit the page, he sees a text field. he can input things and save it. This looks fairly easy to set up. You either have something like a template_positions table which stores the content of those fields. Case: I now have a bit of a blockade keeping things as simple as possible. Assume you have the same tag given in your example, and additionally, <layout> and <repeat> tags. Here's an example how they should be used: <repeat> <layout name="image-left"> <image /> <text_field /> </layout> <layout name="image-right"> <text_field /> <image /> </layout> </repeat> We now have a block which can be repeated, obviously. This means: when creting/editing a page containing such a template block, I can choose between a layout image-left and image-right which then gets inserted as content element (where content for <image /> and <text_field /> gets stored). And because this is inside a <repeat>, content elements from the given layouts can be inserted multiple times. How do you store this? Simply said, this could be stored with the same setup I've wrote in the example above, I just need to add a parent_id or something similiar to maintain a hierarchy. but I think I am missing something. At least the relation between an inserted content element and the origin/insertion point is missing. And what happens when I update the template file? Do I have to give every custom tag that acts as editable part of a template an identifier that matches an identifier in the template to substitue them correctly? Or can you think of a clean solution that might be better?

  Read the article

• Structuring Access Control In Hierarchical Object Graph

  - by SB2055

  I have a Folder entity that can be Moderated by users. Folders can contain other folders. So I may have a structure like this: Folder 1 Folder 2 Folder 3 Folder 4 I have to decide how to implement Moderation for this entity. I've come up with two options: Option 1 When the user is given moderation privileges to Folder 1, define a moderator relationship between Folder 1 and User 1. No other relationships are added to the db. To determine if the user can moderate Folder 3, I check and see if User 1 is the moderator of any parent folders. This seems to alleviate some of the complexity of handling updates / moved entities / additions under Folder 1 after the relationship has been defined, and reverting the relationship means I only have to deal with one entity. Option 2 When the user is given moderation privileges to Folder 1, define a new relationship between User 1 and Folder 1, and all child entities down to the grandest of grandchildren when the relationship is created, and if it's ever removed, iterate back down the graph to remove the relationship. If I add something under Folder 2 after this relationship has been made, I just copy all Moderators into the new Entity. But when I need to show only the top-level Folders that a user is Moderating, I need to query all folders that have a parent folder that the user does not moderate, as opposed to option 1, where I just query any items that the user is moderating. Thoughts I think it comes down to determining if users will be querying for all parent items more than they'll be querying child items... if so, then option 1 seems better. But I'm not sure. Is either approach better than the other? Why? Or is there another approach that's better than both? I'm using Entity Framework in case it matters.

  Read the article

• Trees and macros with tikz

  - by Tsf

  I am trying to build my trees using macros but I don't get the result I want. Here is a minimal example: \documentclass{article} \usepackage{tikz} \usetikzlibrary{trees} \newcommand{\LeafNode}[1]{% child {node {#1}} } \newcommand{\InnerNode}[3]{% child {node {#3} #1 #2 } } \begin{document} \begin{tikzpicture} \node (A) {A} \LeafNode{B} \LeafNode{C} ; \end{tikzpicture}% \hspace{2cm}% \begin{tikzpicture} \node (A) {A} \InnerNode{\LeafNode{D}}{\LeafNode{E}}{B} \LeafNode{C} ; \end{tikzpicture} \end{document} I expected this to produce two trees: A A / \ / \ B C B C / \ D E but I am getting: A | A B | | B D | | C C Am I missing something or there is no way to do it? BTW, if I omit the label on my root node, I get a PGF error: ! Package pgf Error: No shape named is known. -- Tsf

  Read the article

• Do you play Sudoku ?

  - by Gilles Haro

  Did you know that 11gR2 database could solve a Sudoku puzzle with a single query and, most of the time, and this in less than a second ? The following query shows you how ! Simply pass a flattened Sudoku grid to it a get the result instantaneously ! col "Solution" format a9 col "Problem" format a9 with Iteration( initialSudoku, Step, EmptyPosition ) as ( select initialSudoku, InitialSudoku, instr( InitialSudoku, '-' )        from ( select '--64----2--7-35--1--58-----27---3--4---------4--2---96-----27--7--58-6--3----18--' InitialSudoku from dual )    union all    select initialSudoku        , substr( Step, 1, EmptyPosition - 1 ) || OneDigit || substr( Step, EmptyPosition + 1 )         , instr( Step, '-', EmptyPosition + 1 )      from Iteration         , ( select to_char( rownum ) OneDigit from dual connect by rownum <= 9 ) OneDigit     where EmptyPosition > 0       and not exists          ( select null              from ( select rownum IsPossible from dual connect by rownum <= 9 )             where OneDigit = substr( Step, trunc( ( EmptyPosition - 1 ) / 9 ) * 9 + IsPossible, 1 )   -- One line must contain the 1-9 digits                or OneDigit = substr( Step, mod( EmptyPosition - 1, 9 ) - 8 + IsPossible * 9, 1 )      -- One row must contain the 1-9 digits                or OneDigit = substr( Step, mod( trunc( ( EmptyPosition - 1 ) / 3 ), 3 ) * 3           -- One square must contain the 1-9 digits                            + trunc( ( EmptyPosition - 1 ) / 27 ) * 27 + IsPossible                            + trunc( ( IsPossible - 1 ) / 3 ) * 6 , 1 )          ) ) select initialSudoku "Problem", Step "Solution"    from Iteration  where EmptyPosition = 0 ;   The Magic thing behind this is called Recursive Subquery Factoring. The Oracle documentation gives the following definition: If a subquery_factoring_clause refers to its own query_name in the subquery that defines it, then the subquery_factoring_clause is said to be recursive. A recursive subquery_factoring_clause must contain two query blocks: the first is the anchor member and the second is the recursive member. The anchor member must appear before the recursive member, and it cannot reference query_name. The anchor member can be composed of one or more query blocks combined by the set operators: UNION ALL, UNION, INTERSECT or MINUS. The recursive member must follow the anchor member and must reference query_name exactly once. You must combine the recursive member with the anchor member using the UNION ALL set operator. This new feature is a replacement of this old Hierarchical Query feature that exists in Oracle since the days of Aladdin (well, at least, release 2 of the database in 1977). Everyone remembers the old syntax : select empno, ename, job, mgr, level      from   emp      start with mgr is null      connect by prior empno = mgr; that could/should be rewritten (but not as often as it should) as withT_Emp (empno, name, level) as        ( select empno, ename, job, mgr, level             from   emp             start with mgr is null             connect by prior empno = mgr        ) select * from   T_Emp; which uses the "with" syntax, whose main advantage is to clarify the readability of the query. Although very efficient, this syntax had the disadvantage of being a Non-Ansi Sql Syntax. Ansi-Sql version of Hierarchical Query is called Recursive Subquery Factoring. As of 11gR2, Oracle got compliant with Ansi Sql and introduced Recursive Subquery Factoring. It is basically an extension of the "With" clause that enables recursion. Now, the new syntax for the query would be with T_Emp (empno, name, job, mgr, hierlevel) as       ( select E.empno, E.ename, E.job, E.mgr, 1 from emp E where E.mgr is null         union all         select E.empno, E.ename, E.job, E.mgr, T.hierlevel + 1from emp E                                                                                                            join T_Emp T on ( E.mgr = T.empno ) ) select * from   T_Emp; The anchor member is a replacement for the "start with" The recursive member is processed through iterations. It joins the Source table (EMP) with the result from the Recursive Query itself (T_Emp) Each iteration works with the results of all its preceding iterations.     Iteration 1 works on the results of the first query     Iteration 2 works on the results of Iteration 1 and first query     Iteration 3 works on the results of Iteration 1, Iteration 2 and first query. So, knowing that, the Sudoku query it self-explaining; The anchor member contains the "Problem" : The Initial Sudoku and the Position of the first "hole" in the grid. The recursive member tries to replace the considered hole with any of the 9 digit that would satisfy the 3 rules of sudoku Recursion progress through the grid until it is complete.   Another example :  Fibonaccy Numbers :  un = (un-1) + (un-2) with Fib (u1, u2, depth) as   (select 1, 1, 1 from dual    union all    select u1+u2, u1, depth+1 from Fib where depth<10) select u1 from Fib; Conclusion Oracle brings here a new feature (which, to be honest, already existed on other concurrent systems) and extends the power of the database to new boundaries. It’s now up to developers to try and test it and find more useful application than solving puzzles… But still, solving a Sudoku in less time it takes to say it remains impressive… Interesting links: You might be interested by the following links which cover different aspects of this feature Oracle Documentation Lucas Jellema 's Blog Fibonaci Numbers

  Read the article

• Trying to use linq to search based on table with hierarchical data.

  - by Steph

  Duplicate many times over (and also these) I have a table called Types that has the following columns. ID Level Name ParentID (The ID of the parent row) and a table called ParentObject which has the following columns. ID TypeID there are 4 different level (possibly to be expanded to more). So if I had ID: 1 Level: 0 Name: Level0 ParentID: null ID: 2 Level: 1 Name: Level1 ParentID: 1 ID: 3 Level: 2 Name: Level2 ParentID: 2 ID: 4 Level: 3 Name: Level3 ParentID: 3 ID: 5 Level: 4 Name: Level4 ParentID: 4 In the ParentObject table I store the tree by just storing the lowest level ID. So if the ID i have is 4, I know that the tree actually goes Level0 - Level1 - Level2 - Level3 Basically, I need to be able to search all objects for a certain Type, or Type Level 2 for example in a linq statement. Say that the TypeID stored in the ParentObject table is 4, so Level3. But I actually want to search for all ParentObjects where the Level 2 type has an ID of 3. What would be the best way to do this since the id stored could be a level1 or a level2, etc.? Preferably in one linq statement if possible.

  Read the article

• How to select all parents of a node in a hierarchical mysql table?

  - by Ehsan Khodarahmi

  I have a MySQL table that represents data for a tree GUI component, here's the structure of my table: treeTable ( id INT NOT NULL PRIMARY KEY, parentId INT, name VARCHAR(255) ); parentId is a self-referencing foreign key. Now I want to write a stored procedure which gets a node id and returns a result set that contains that node and all of its parents. For example, suppose that my table has filled with this data: 1, null, 'root' 2, 1 , 'level_1' 3, 2 , 'level_2' Now I want to get all parent nodes of node 3 (nodes 1 and 2) and return a result set that contains all tree records. Can anybody help me please?

  Read the article

• How do I display non-normalized data in a hierarchical structure?

  - by rofly

  My issue is that I want to display data in a hierarchal structure as so: Democrat County Clerk Candidate 1 Candidate 2 Magistrate Candidate 1 Candidate 2 Candidate 3 But I'm retrieving the dataset like this: Party | Office | Candidate Democrat | County Clerk | Candidate 1 Democrat | County Clerk | Candidate 2 Democrat | Magistrate | Candidate 1 Democrat | Magistrate | Candidate 2 Democrat | Magistrate | Candidate 3 I planned on using nested repeaters, but I need a distinct value of Party, and then distinct values of office name within that party in order to do it. Are there any .NET functions to easily do what I'm attempting to? Would there be a better way of displaying the information other than repeaters? Thanks in advance!

  Read the article

• Show Diff of two trees in Eclipse

  - by ericbodden

  In Eclipse, I am using a TreeViewer to show a custom tree, whose contents are drawn from an ITreeContentProvider. Now I am trying to create a second view that allows me to automatically show a two-way comparisons of two such trees. I found various views for textual comparison within Eclipse, but I could not find an easy way to show the structural differences between two arbitrary trees. Any thoughts?

  Read the article

• Finding the most frequent subtrees in a collection of (parse) trees

  - by peter.murray.rust

  I have a collection of trees whose nodes are labelled (but not uniquely). Specifically the trees are from a collection of parsed sentences (see http://en.wikipedia.org/wiki/Treebank). I wish to extract the most common subtrees from the collection - performance is not (yet) an issue. I'd be grateful for algorithms (ideally Java) or pointers to tools which do this for treebanks. Note that order of child nodes is important. EDIT @mjv. We are working in a limited domain (chemistry) which has a stylised language so the varirty of the trees is not huge - probably similar to children's readers. Simple tree for "the cat sat on the mat". <sentence> <nounPhrase> <article/> <noun/> </nounPhrase> <verbPhrase> <verb/> <prepositionPhrase> <preposition/> <nounPhrase> <article/> <noun/> </nounPhrase> </prepositionPhrase> </verbPhrase> </sentence> Here the sentence contains two identical part-of-speech subtrees (the actual tokens "cat". "mat" are not important in matching). So the algorithm would need to detect this. Note that not all nounPhrases are identical - "the big black cat" could be: <nounPhrase> <article/> <adjective/> <adjective/> <noun/> </nounPhrase> The length of sentences will be longer - between 15 to 30 nodes. I would expect to get useful results from 1000 trees. If this does not take more than a day or so that's acceptable. Obviously the shorter the tree the more frequent, so nounPhrase will be very common. EDIT If this is to be solved by flattening the tree then I think it would be related to Longest Common Substring, not Longest Common Sequence. But note that I don't necessarily just want the longest - I want a list of all those long enough to be "interesting" (criterion yet to be decided).

  Read the article

• B-trees, databases, sequential inputs, and speed.

  - by IanC

  I know from experience that b-trees have awful performance when data is added to them sequentially (regardless of the direction). However, when data is added randomly, best performance is obtained. This is easy to demonstrate with the likes of an RB-Tree. Sequential writes cause a maximum number of tree balances to be performed. I know very few databases use binary trees, but rather used n-order balanced trees. I logically assume they suffer a similar fate to binary trees when it comes to sequential inputs. This sparked my curiosity. If this is so, then one could deduce that writing sequential IDs (such as in IDENTITY(1,1)) would cause multiple re-balances of the tree to occur. I have seen many posts argue against GUIDs as "these will cause random writes". I never use GUIDs, but it struck me that this "bad" point was in fact a good point. So I decided to test it. Here is my code: SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE TABLE [dbo].[T1]( [ID] [int] NOT NULL CONSTRAINT [T1_1] PRIMARY KEY CLUSTERED ([ID] ASC) ) GO CREATE TABLE [dbo].[T2]( [ID] [uniqueidentifier] NOT NULL CONSTRAINT [T2_1] PRIMARY KEY CLUSTERED ([ID] ASC) ) GO declare @i int, @t1 datetime, @t2 datetime, @t3 datetime, @c char(300) set @t1 = GETDATE() set @i = 1 while @i < 2000 begin insert into T2 values (NEWID(), @c) set @i = @i + 1 end set @t2 = GETDATE() WAITFOR delay '0:0:10' set @t3 = GETDATE() set @i = 1 while @i < 2000 begin insert into T1 values (@i, @c) set @i = @i + 1 end select DATEDIFF(ms, @t1, @t2) AS [Int], DATEDIFF(ms, @t3, getdate()) AS [GUID] drop table T1 drop table T2 Note that I am not subtracting any time for the creation of the GUID nor for the considerably extra size of the row. The results on my machine were as follows: Int: 17,340 ms GUID: 6,746 ms This means that in this test, random inserts of 16 bytes was almost 3 times faster than sequential inserts of 4 bytes. Would anyone like to comment on this? Ps. I get that this isn't a question. It's an invite to discussion, and that is relevant to learning optimum programming.

  Read the article

• LDAP (slapd) creating users with access to specific trees

  - by Josh

  I am setting up a CentOS server with Virtualmin and Postfix, and I am trying to use LDAP to store unix users, groups, Postfix aliases and virtual domains. I am following the instructions from Webmin's site. I have created an LDAP domain and configured Postfix to fetch Aliases and Virtual Domains from LDAP, but in order to do so I had to configure postfix to authenticate with the master LDAP account, cn=Manager,dc=mydomain,dc=com. This seems like a terrible idea because that account has access to the Users and Groups, which postfix does not need access to. How can I create a new LDAP account for Postfix which only has access to the LDAP trees Postfix needs?

  Read the article

• How to generate and encode (for use in GA), random, strict, binary rooted trees with N leaves?

  - by Peter Simon

  First, I am an engineer, not a computer scientist, so I apologize in advance for any misuse of nomenclature and general ignorance of CS background. Here is the motivational background for my question: I am contemplating writing a genetic algorithm optimizer to aid in designing a power divider network (also called a beam forming network, or BFN for short). The BFN is intended to distribute power to each of N radiating elements in an array of antennas. The fraction of the total input power to be delivered to each radiating element has been specified. Topologically speaking, a BFN is a strictly binary, rooted tree. Each of the (N-1) interior nodes of the tree represents the input port of an unequal, binary power splitter. The N leaves of the tree are the power divider outputs. Given a particular power divider topology, one is still free to map the power divider outputs to the array inputs in an arbitrary order. There are N! such permutations of the outputs. There are several considerations in choosing the desired ordering: 1) The power ratio for each binary coupler should be within a specified range of values. 2) The ordering should be chosen to simplify the mechanical routing of the transmission lines connecting the power divider. The number of ouputs N of the BFN may range from, say, 6 to 22. I have already written a genetic algorithm optimizer that, given a particular BFN topology and desired array input power distribution, will search through the N! permutations of the BFN outputs to generate a design with compliant power ratios and good mechanical routing. I would now like to generalize my program to automatically generate and search through the space of possible BFN topologies. As I understand it, for N outputs (leaves of the binary tree), there are $C_{N-1}$ different topologies that can be constructed, where $C_N$ is the Catalan number. I would like to know how to encode an arbitrary tree having N leaves in a way that is consistent with a chromosomal description for use in a genetic algorithm. Also associated with this is the need to generate random instances for filling the initial population, and to implement crossover and mutations operators for this type of chromosome. Any suggestions will be welcome. Please minimize the amount of CS lingo in your reply, since I am not likely to be acquainted with it. Thanks in advance, Peter

  Read the article

• With ' N ' no of nodes, how many different Binary and Binary Search Trees possible ?

  - by siva

  For Binary tree: You no need to consider tree node values, I am interested about different tree topologies with 'N' nodes. For Binary Search Tree: We obviously consider tree node values.

  Read the article

• What is the best algorithm to use in creating binary trees??

  - by Hanseh

  I've been doing a research about the best algorithm to use in creating a binary tree implementation. THe top entry in my list is nested sets. Are there any other alternative or better algorithm??

  Read the article

< Previous Page | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >