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  • Netlogo: error when putting variable in table, only constants allowe??

    - by Chantal
    Hello, Currently I am working on a Netlogo program where I need to use nodes and links for vehicle routing problem. (links are called streets in the program) Here I have some practical problems of how to input variable linkspeed in a table with another node. Constants like 200 etc are fine. Online I found some examples where variables are used, but I do not know why I keep getting the following error: Expected a constant. (or why netlogo expects a constant) Here is the relevant piece of code: extensions [table] streets-own [linkspeed linktoll] nodes-own [netw] ;; In another piece of code linkspeed is assigned successfully to the links to cheapcalc ;; start conditions set costs very high 300000 ;; state 3 unsearched state 2 searching state 1 searched (for later purposes) ask nodes [ set i 0 set j count nodes set netw table:make while [i < j][ table:put netw (i) [3000000 3] set i (i + 1)]] set i 0 let k 0 ask node 35 ;; here i use node 35 as an example. ;; node 35 is connected to node 34, 36, 20 and 50 [table:put netw (35) [0 1] ;; node need to search costs to travel to itself ;; putting constants is ok. while [i < j] [ask my-links [ask both-ends [if (who != 35) [set color blue ;; set temp ([linkspeed] of street 35 who) ;; here my real goal is to put this in stat of i. but i is easier than linkspeed. table:put netw (who) [ i 2 ] ] ] ] set i (i + 1)] ] ;; next node for later, no it is just repetition of the same. end I hope somebody knows what is going on... Kind regards, Chantal

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  • PHP & cUrl - POST problems in while loop.

    - by Max Hoff
    I have a while loop, with cUrl inside. (I can't use curl_multi for various reasons.) The problem is that cUrl seems to save the data it POSTS after each loop traversal. For instance, if parameter X is One the first loop through, and if it's Two the second loop through, cUrl posts: "One,Two". It should just POST "Two".(This is despite closing and unsetting the curl handle.) Here's a simplified version of the code (with unecessary info stripped out): while(true){ // code to form the $url. this code is local to the loop. so the variables should be "erased" and made new for each loop through. $ch = curl_init(); $userAgent = 'Googlebot/2.1 (http://www.googlebot.com/bot.html)'; curl_setopt($ch,CURLOPT_USERAGENT, $userAgent); curl_setopt($ch,CURLOPT_URL,$url); curl_setopt($ch,CURLOPT_POST,count($fields)); curl_setopt($ch,CURLOPT_POSTFIELDS,$fields_string); curl_setopt($ch, CURLOPT_FAILONERROR, true); curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true); curl_setopt($ch, CURLOPT_AUTOREFERER, true); curl_setopt($ch, CURLOPT_RETURNTRANSFER,true); curl_setopt($ch, CURLOPT_TIMEOUT, 10); $html = curl_exec($ch); curl_close($ch); unset($ch); $dom = new DOMDocument(); @$dom->loadHTML($html); $xpath = new DOMXPath($dom); $resultTable = $xpath->evaluate("/html/body//table"); // $resultTable is 20 the first time through the loop, and 0 everytime thereafter becauset he POSTing doesn't work right with the "saved" parameters. What am I doing wrong here?

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  • How to reload a tableView i.e call the viewDidLoad method if a condition is met

    - by Kquane Ingram
    The problem is this i need a way to basically erase all the entry data a user placed into my arrays if a condition is met. Im new to Objective-C and iOS programming, but i believed the solution might be in calling the viewDidLoad method, thus it would virtually refresh the applications with the values of the array reset to default. If there is any other logical way of doing this i would appreciate the help. In short i need to refresh the arrays as they were when the application first launched and the user did not select anything. This is the part where i need it to refresh. if ([gradeRecieved objectAtIndex:i]==nil) { break; // if this condition is met the program must begin anew. Edit* I need to recall the - (void)viewDidLoad method here is more of the code. -(IBAction)button:(id)sender{ int i = 0; int sum = 0; int gradeEarned; int creditHours = 3; for ( i=0;i<8 ; i++) { if ([[points objectAtIndex:i] tag]==GradeA.intValue) { [gradeRecieved replaceObjectAtIndex:i withObject:GradeA]; } if ([[points objectAtIndex:i]tag]==GradeB.intValue) { [gradeRecieved replaceObjectAtIndex:i withObject:GradeB]; } if ([[points objectAtIndex:i]tag]==GradeC.intValue){ [gradeRecieved replaceObjectAtIndex:i withObject:GradeC]; } if ([gradeRecieved objectAtIndex:i]==nil) { break; // if this condition is met the program must restart. } } while ( i<[gradeRecieved count]) { if ([gradeRecieved objectAtIndex:i] == GradeA ) { [finArray replaceObjectAtIndex:i withObject:GradeA]; i++; continue; } if ([gradeRecieved objectAtIndex:i] == GradeB ) { [gradeRecieved replaceObjectAtIndex:i withObject:GradeB]; i++; continue; } if ([gradeRecieved objectAtIndex:i] == GradeC ) { [gradeRecieved replaceObjectAtIndex:i withObject:GradeC]; i++; continue; } }

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  • HOWTO: implement a jQuery version of ASP.Net MVC "Strongly Typed Partial Views"

    - by Sam Carleton
    I am working on a multi-page assessment form where the questions/responses are database driven. Currently I the basic system working with Html.BeginForm via standard ASP.Net MVC. At this point in time, the key to the whole system is the 'Strongly Typed Partial Views'. When the question/response is read from the database, the response type determines which derived model is created and added to the collection. The main view it iterates through the collection and uses the 'Strongly Typed Partial Views' system of ASP.Net MVC to determine which view to render the correct type of response (radio button, drop down, or text box). I would like to change this process from a Html.BeginForm to Ajax.BeginForm. The problem is I don't have a clue as to how to implement the dynamic creation of the question/response in the JavaScript/jQuery world. Any thoughts and/or suggestions? Here is the current code to generate the dynamic form: @using (Html.BeginForm(new { mdsId = @Model.MdsId, sectionId = @Model.SectionId })) { <div class="SectionTitle"> <span>Section @Model.SectionName - @Model.SectionDescription</span> <span style="float: right">@Html.CheckBoxFor(x => x.ShowUnansweredQuestions) Show only unaswered questions</span> </div> @Html.HiddenFor(x => x.PrevSectionId) @Html.HiddenFor(x => x.NextSectionId) for (var i = 0; i < Model.answers.Count(); i++) { @Html.EditorFor(m => m.answers[i]); } }

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  • How do I model teams and gameplay in this scorekeeping application?

    - by Eric Hill
    I'm writing a scorekeeping application for card game that has a few possibly-interesting constraints. The application accepts user registrations for players, then lets them check-in to a particular game (modeled as Event). After the final player registers, the app should generate teams, singles or doubles, depending on the preference of the person running the game and some validations (can't do doubles if there's an odd number checked in). There are @event.teams.count rounds in the game. To sum up: An event consists of `@event.teams.count` rounds; Teams can have 1 or more players Events have n or n/2 teams (depending on whether it's singles or doubles) Users will be members of different teams at different events Currently I have a rat's nest of associations: class User < ActiveRecord::Base has_many :teams, :through => :players has_many :events, :through => :teams class Event < ActiveRecord::Base has_many :rounds has_many :teams has_many :players, :through => :teams class Player < ActiveRecord::Base belongs_to :user belongs_to :team end class Team < ActiveRecord::Base has_many :players belongs_to :event end class Round < ActiveRecord::Base belongs_to :event belongs_to :user end The sticky part is team generation. I have basically a "start game" button that should freeze the registrations and pair up teams either singly or doubly, and render to Round#new so that the first (and subsequent) matches can be scored. Currently I'm implementing this as a check on Round#new that calls Event#generate_teams and displays the view: # Event#generate_teams def generate_teams # User has_many :events, :through => :registrations # self.doubles is a boolean denoting 2 players per team registrations.in_groups_of(self.doubles ? 2 : 1, nil).each do |side| self.teams << Player.create(self,side) end end Which doesn't work. Should there maybe be a Game model that ties everything together rather than (my current method) defining the game as an abstraction via the relationships between Events, Users, and Rounds (and Teams and Players and etc.)? My head is swimming.

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  • How can I work out what events are being waited for with WinDBG in a kernel debug session

    - by Benj
    I'm a complete WinDbg newbie and I've been trying to debug a WindowsXP problem that a customer has sent me where our software and some third party software prevent windows from logging off. I've reproduced the problem and have verified that only when our software and the customers software are both installed (although not necessarily running at logoff) does the log off problem occur. I've observed that WM_ENDSESSION messages are not reaching the running windows when the user tries to log off and I know that the third party software uses a kernel driver. I've been looking at the processes in WinDbg and I know that csrss.exe would normally send all the windows a WM_ENDSESSION message. When I ran: !process 82356020 6 To look at csrss.exe's stack I can see: WARNING: Frame IP not in any known module. Following frames may be wrong. 00000000 00000000 00000000 00000000 00000000 0x7c90e514 THREAD 8246d998 Cid 0248.02a0 Teb: 7ffd7000 Win32Thread: e1627008 WAIT: (WrUserRequest) UserMode Non-Alertable 8243d9f0 SynchronizationEvent 81fe0390 SynchronizationEvent Not impersonating DeviceMap e1004450 Owning Process 82356020 Image: csrss.exe Attached Process N/A Image: N/A Wait Start TickCount 1813 Ticks: 20748 (0:00:05:24.187) Context Switch Count 3 LargeStack UserTime 00:00:00.000 KernelTime 00:00:00.000 Start Address 0x75b67cdf Stack Init f80bd000 Current f80bc9c8 Base f80bd000 Limit f80ba000 Call 0 Priority 14 BasePriority 13 PriorityDecrement 0 DecrementCount 0 Kernel stack not resident. ChildEBP RetAddr Args to Child f80bc9e0 80500ce6 00000000 8246d998 804f9af2 nt!KiSwapContext+0x2e (FPO: [Uses EBP] [0,0,4]) f80bc9ec 804f9af2 804f986e e1627008 00000000 nt!KiSwapThread+0x46 (FPO: [0,0,0]) f80bca24 bf80a4a3 00000002 82475218 00000001 nt!KeWaitForMultipleObjects+0x284 (FPO: [Non-Fpo]) f80bca5c bf88c0a6 00000001 82475218 00000000 win32k!xxxMsgWaitForMultipleObjects+0xb0 (FPO: [Non-Fpo]) f80bcd30 bf87507d bf9ac0a0 00000001 f80bcd54 win32k!xxxDesktopThread+0x339 (FPO: [Non-Fpo]) f80bcd40 bf8010fd bf9ac0a0 f80bcd64 00bcfff4 win32k!xxxCreateSystemThreads+0x6a (FPO: [Non-Fpo]) f80bcd54 8053d648 00000000 00000022 00000000 win32k!NtUserCallOneParam+0x23 (FPO: [Non-Fpo]) f80bcd54 7c90e514 00000000 00000022 00000000 nt!KiFastCallEntry+0xf8 (FPO: [0,0] TrapFrame @ f80bcd64) This waitForMultipleObjects looks interesting because I'm wondering if csrss.exe is waiting on some event which isn't arriving to allow the logoff. Can anyone tell me how I might find out what event it's waiting for anything else I might do to further investigate the problem?

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  • Parsing two-dimensional text

    - by alexbw
    I need to parse text files where relevant information is often spread across multiple lines in a nonlinear way. An example: 1234 1 IN THE SUPERIOR COURT OF THE STATE OF SOME STATE 2 IN AND FOR THE COUNTY OF SOME COUNTY 3 UNLIMITED JURISDICTION 4 --o0o-- 5 6 JOHN SMITH and JILL SMITH, ) ) 7 Plaintiffs, ) ) 8 vs. ) No. 12345 ) 9 ACME CO, et al., ) ) 10 Defendants. ) ___________________________________) I need to pull out Plaintiff and Defendant identities. These transcripts have a very wide variety of formattings, so I can't always count on those nice parentheses being there, or the plaintiff and defendant information being neatly boxed off, e.g.: 1 SUPREME COURT OF THE STATE OF SOME OTHER STATE COUNTY OF COUNTYVILLE 2 First Judicial District Important Litigation 3 --------------------------------------------------X THIS DOCUMENT APPLIES TO: 4 JOHN SMITH, 5 Plaintiff, Index No. 2000-123 6 DEPOSITION 7 - against - UNDER ORAL EXAMINATION 8 OF JOHN SMITH, 9 Volume I 10 ACME CO, et al, 11 Defendants. 12 --------------------------------------------------X The two constants are: "Plaintiff" will occur after the name of the plaintiff(s), but not necessarily on the same line. Plaintiffs and defendants' names will be in upper case. Any ideas?

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  • Google Spreadsheet API problem: memory exceeded

    - by Robbert
    Hi guys, Don't know if anyone has experience with the Google Spreadsheets API or the Zend_GData classes but it's worth a go: When I try to insert a value in a 750 row spreadsheet, it takes ages and then throws an error that my memory limit (which is 128 MB!) was exceeded. I also got this when querying all records of this spreadsheet but this I can imaging because it's quite a lot of data. But why does this happen when inserting a row? That's not too complex, is it? Here's the code I used: public function insertIntoSpreadsheet($username, $password, $spreadSheetId, $data = array()) { $service = Zend_Gdata_Spreadsheets::AUTH_SERVICE_NAME; $client = Zend_Gdata_ClientLogin::getHttpClient($username, $password, $service); $client->setConfig(array( 'timeout' => 240 )); $service = new Zend_Gdata_Spreadsheets($client); if (count($data) == 0) { die("No valid data"); } try { $newEntry = $service->insertRow($data, $spreadSheetId); return true; } catch (Exception $e) { return false; } }

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  • Do I have to allocate and free records when using TList<T> in Delphi?

    - by afrazier
    The question more or less says it all. Given the following record structure: type TPerson = record Name: string; Age: Integer; end; PPerson = ^TPerson; TPersonList = TList<TPerson>; Is the following code valid? procedure ReadPeople(DataSet: TDataSet; PersonList: TPersonList); begin PersonList.Count := DataSet.RecordCount; if DataSet.RecordCount = 0 then Exit; DataSet.First; while not DataSet.Eof do begin PersonList[DataSet.RecNo].Name := DataSet.FieldByName('Name').AsString; PersonList[DataSet.RecNo].Age := DataSet.FieldByName('Age').AsInteger; DataSet.Next; end; end; Do I have to use GetMem/FreeMem to allocate and free records an instance of TPersonList, or am I free to directly access the TPersonList entries directly? My gut says that the code should be valid, though I'm not sure if there's any wrinkles related to record initialization or finalization.

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  • how to find a control inside ItemsPanelTemplate in wpf?

    - by kakopappa
    I am trying to access a Grid inside the DataTemplate while the ItemsControl is binded by ItemsSource. this is the full XMAL code, How do i find a certain element from outside? for (int i = 0; i < allViewControl.Items.Count; i++) { var container = allViewControl.ItemContainerGenerator.ContainerFromItem(allViewControl.Items[i]) as FrameworkElement; var grid = allViewControl.ItemTemplate.FindName("grid", container) as DataGrid; } i found this always returning null ? <ScrollViewer Grid.Row="0" HorizontalScrollBarVisibility="Disabled" VerticalScrollBarVisibility="Auto"> <ItemsControl x:Name="allViewControl" Focusable="False" HorizontalContentAlignment="Center" Grid.IsSharedSizeScope="true" ItemsSource="{Binding AllClassCharacters}" ItemTemplate="{StaticResource CharacterViewModelTemplate}" > <ItemsControl.ItemsPanel> <ItemsPanelTemplate> <Extensions:AnimatedWrapPanel IsItemsHost="true" /> </ItemsPanelTemplate> </ItemsControl.ItemsPanel> </ItemsControl> </ScrollViewer> <DataTemplate x:Key="CharacterViewModelTemplate" DataType="{x:Type ViewModel:CharacterViewModel}"> <Grid x:Name="grid" Width="200" Height="Auto" MinHeight="115" Margin="1" MinWidth="130" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" RenderTransformOrigin="0.5,0.5" Background="#66000000" > <Grid.RowDefinitions> <RowDefinition Height="70"/> <RowDefinition Height="*"/> </Grid.RowDefinitions> <Grid.ColumnDefinitions> <ColumnDefinition Width="*" /> <ColumnDefinition Width="*" /> </Grid.ColumnDefinitions> <ProgressBar x:Name="playerProgressBar" VerticalAlignment="Top" Background="Transparent" Height="5" Width="Auto" Value="0" Visibility="Collapsed" Grid.Column="0" Grid.Row="0" Grid.ColumnSpan ="2" Grid.RowSpan="2" Foreground="White" BorderThickness="0" Style="{DynamicResource ProgressBarStyle1}" /> </Grid>

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  • using xpath get the correct value in selectName

    - by Sangeeta
    Below I have written the code. I need help to get the right value in selectName. I am new to XPath. Basically with this code I am trying to achieve if employeeName = Chris I need to return 23549 to the calling function. Please help. Part of the code: public static string getEmployeeeID(string employeeName) { Cache cache = HttpContext.Current.Cache; string cacheNameEmployee = employeeName + "Tech"; if (cache[cacheNameEpm] == null) { XPathDocument doc = new XPathDocument(HttpContext.Current.Request.MapPath("inc/xml/" + SiteManager.Site.ToString() + "TechToolTip.xml")); XPathNavigator navigator = doc.CreateNavigator(); string selectName = "/Technologies/Technology[FieldName='" + fieldName + "']/EpmId"; XPathNodeIterator nodes = navigator.Select(selectName); if (nodes.Count > 0) { if (nodes.Current.Name.Equals("FieldName")) //nodes.Current.MoveToParent(); //nodes.Current.MoveToParent(); //nodes.Current.MoveToChild("//EpmId"); cache.Add(cacheNameEpm, nodes.Current.Value, null, DateTime.Now + new TimeSpan(4, 0, 0), System.Web.Caching.Cache.NoSlidingExpiration, CacheItemPriority.Default, null); } } return cache[cacheNameEpm] as string; } XML file <?xml version="1.0" encoding="utf-8" ?> <Employees> <Employee> <EName>Chris</EName> <ID>23556</ID> </Employee> <Employee> <EName>CBailey</EName> <ID>22222</ID> </Employee> <Employee> <EName>Meghan</EName> <ID>12345</ID> </Employee> </Employees> PLEASE NOTE:This XML file has 100 nodes. I just put 1 to indicate the structure.

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  • lock shared data using c#

    - by menacheb
    Hi, I have a program (C#) with a list of tests to do. Also, I have two thread. one to add task into the list, and one to read and remove from it the performed tasks. I'm using the 'lock' function each time one of the threads want to access to the list. Another thing I want to do is, if the list is empty, the thread who need to read from the list will sleep. and wake up when the first thread add a task to the list. Here is the code I wrote: ... List<String> myList = new List(); Thread writeThread, readThread; writeThread = new Thread(write); writeThread.Start(); readThraed = new Thread(read); readThread.Start(); ... private void write() { while(...) { ... lock(myList) { myList.Add(...); } ... if (!readThread.IsAlive) { readThraed = new Thread(read); readThread.Start(); } ... } ... } private void read() { bool noMoreTasks = false; while (!noMoreTasks) { lock (MyList)//syncronize with the ADD func. { if (dataFromClientList.Count > 0) { String task = myList.First(); myList.Remove(task); } else { noMoreTasks = true; } } ... } readThread.Abort(); } Apparently I did it wrong, and it's not performed as expected (The readTread does't read from the list). Does anyone know what is my problem, and how to make it right? Many thanks,

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  • Using XSLT to Find Nodes Given a Set of Parameters

    - by davecardwell
    Sorry about the title—wasn’t sure how to word it. Basically I have some XML like this: <countries> <country handle="bangladesh"/> <country handle="india"/> <country handle="pakistan"/> </countries> And some XSLT like this (which doesn’t work): <xsl:template match="/countries"> <xsl:param name="popular"/> <xsl:apply-templates select="country[count($popular/country[@handle = current()/@handle]) &gt; 0]" /> </xsl:template> <xsl:template match="/countries/country"> … </xsl:template> I want to pass in a list of popular destinations like this: <popular> <country handle="india"/> <country handle="pakistan"/> </popular> …to the /countries template and have it only operate on the ones in the $popular param. At the moment this simply does nothing. Changing the selector to country[true()] operates on them all, so at least I know the basic structure is right. Any ideas? I think I may be getting confused by what is currently “current()”.

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  • how to use a parameterized function for the Default Binding of a Sql Server column

    - by Walt Gaber
    I have a table that catalogs selected files from multiple sources. I want to record whether a file is a duplicate of a previously cataloged file at the time the new file is cataloged. I have a column in my table (“primary_duplicate”) to record each entry as ‘P’ (primary) or ‘D’ (duplicate). I would like to provide a Default Binding for this column that would check for other occurrences of this file (i.e. name, length, timestamp) at the time the new file is being recorded. I have created a function that performs this check (see “GetPrimaryDuplicate” below). But I don’t know how to bind this function which requires three parameters to the table’s “primary_duplicate” column as its Default Binding. I would like to avoid using a trigger. I currently have a stored procedure used to insert new records that performs this check. But I would like to ensure that the flag is set correctly if an insert is performed outside of this stored procedure. How can I call this function with values from the row that is being inserted? USE [MyDatabase] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE TABLE [dbo].[FileCatalog]( [id] [uniqueidentifier] NOT NULL, [catalog_timestamp] [datetime] NOT NULL, [primary_duplicate] nchar NOT NULL, [name] nvarchar NULL, [length] [bigint] NULL, [timestamp] [datetime] NULL ) ON [PRIMARY] GO ALTER TABLE [dbo].[FileCatalog] ADD CONSTRAINT [DF_FileCatalog_id] DEFAULT (newid()) FOR [id] GO ALTER TABLE [dbo].[FileCatalog] ADD CONSTRAINT [DF_FileCatalog_catalog_timestamp] DEFAULT (getdate()) FOR [catalog_timestamp] GO ALTER TABLE [dbo].[FileCatalog] ADD CONSTRAINT [DF_FileCatalog_primary_duplicate] DEFAULT (N'GetPrimaryDuplicate(name, length, timestamp)') FOR [primary_duplicate] GO USE [MyDatabase] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE FUNCTION [dbo].[GetPrimaryDuplicate] ( @name nvarchar(255), @length bigint, @timestamp datetime ) RETURNS nchar(1) AS BEGIN DECLARE @c int SELECT @c = COUNT(*) FROM FileCatalog WHERE name=@name and length=@length and timestamp=@timestamp and primary_duplicate = 'P' IF @c > 0 RETURN 'D' -- Duplicate RETURN 'P' -- Primary END GO

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  • Best way to detect similar email addresses?

    - by Chris
    I have a list of ~20,000 email addresses, some of which I know to be fraudulent attempts to get around a "1 per e-mail" limit. ([email protected], [email protected], [email protected], etc...). I want to find similar email addresses for evaluation. Currently I'm using a levenshtein algorithm to check each e-mail against the others in the list and report any with an edit distance of less than 2. However, this is painstakingly slow. Is there a more efficient approach? The test code I'm using now is: using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.IO; using System.Threading; namespace LevenshteinAnalyzer { class Program { const string INPUT_FILE = @"C:\Input.txt"; const string OUTPUT_FILE = @"C:\Output.txt"; static void Main(string[] args) { var inputWords = File.ReadAllLines(INPUT_FILE); var outputWords = new SortedSet<string>(); for (var i = 0; i < inputWords.Length; i++) { if (i % 100 == 0) Console.WriteLine("Processing record #" + i); var word1 = inputWords[i].ToLower(); for (var n = i + 1; n < inputWords.Length; n++) { if (i == n) continue; var word2 = inputWords[n].ToLower(); if (word1 == word2) continue; if (outputWords.Contains(word1)) continue; if (outputWords.Contains(word2)) continue; var distance = LevenshteinAlgorithm.Compute(word1, word2); if (distance <= 2) { outputWords.Add(word1); outputWords.Add(word2); } } } File.WriteAllLines(OUTPUT_FILE, outputWords.ToArray()); Console.WriteLine("Found {0} words", outputWords.Count); } } }

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  • Learning Haskell maps, folds, loops and recursion

    - by Darknight
    I've only just dipped my toe in the world of Haskell as part of my journey of programming enlightenment (moving on from, procedural to OOP to concurrent to now functional). I've been trying an online Haskell Evaluator. However I'm now stuck on a problem: Create a simple function that gives the total sum of an array of numbers. In a procedural language this for me is easy enough (using recursion) (c#) : private int sum(ArrayList x, int i) { if (!(x.Count < i + 1)) { int t = 0; t = x.Item(i); t = sum(x, i + 1) + t; return t; } } All very fine however my failed attempt at Haskell was thus: let sum x = x+sum in map sum [1..10] this resulted in the following error (from that above mentioned website): Occurs check: cannot construct the infinite type: a = a -> t Please bear in mind I've only used Haskell for the last 30 minutes! I'm not looking simply for an answer but a more explanation of it. Thanks in advanced.

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  • Magi squares, recursive

    - by user310827
    Hi, my problem is, I'm trying to permute all posibilities for 3x3 square and check if the combination is magic. I've added a tweak with (n%3==0) if statement that if the sum of numbers in row differs from 15 it breaks the creation of other two lines... but it doesn't work, any suggestions, I call the function with Permute(1). public static class Global { //int[] j = new int[6]; public static int[] a= {0,0,0,0,0,0,0,0,0}; public static int[] b= {0,0,0,0,0,0,0,0,0}; public static int count = 0; } public static void Permute(int n) { int tmp=n-1; for (int i=0;i<9;i++){ if (Global.b[i]==0 ) { Global.b[i]=1; Global.a[n-1]=i+1; if ((n % 3) == 0) { if (Global.a[0+tmp]+Global.a[1+tmp]+Global.a[2+tmp] == 15) { if (n<9) { Permute(n+1); } else { isMagic(Global.a); } } else break; } else { Permute(n+1); } Global.b[i]=0; } } }

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  • C Nested Structure Pointer Problem

    - by Halo
    I have a shared structure, and inside it a request structure: struct shared_data { pthread_mutex_t th_mutex_queue; struct request_queue { int min; int max; char d_name[DIR_SIZE]; pid_t pid; int t_index; } request_queue[BUFSIZE]; int count; int data_buffer_allocation[BUFSIZE]; int data_buffers[BUFSIZE][100]; }; Then I prepare a request; struct shared_data *sdata_ptr; ... ... sdata_ptr->request_queue[index].pid = pid; strcpy(sdata_ptr->request_queue[index].d_name, dir_path_name); sdata_ptr->request_queue[index].min = min; sdata_ptr->request_queue[index].max = max; And the compiler warns me that I'm doing an incompatible implicit declaration in the strcpy function. I guess that's a problem with the pointers, but isn't what I wrote above supposed to be true?

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  • Help with SQL Query

    - by djfrear
    With regards to the following statement: Select * From explorer.booking_record booking_record_ Inner Join explorer.client client_ On booking_record_.labelno = client_.labelno Inner Join explorer.tour_hotel tour_hotel_ On tour_hotel_.tourcode = booking_record_.tourrefcode Inner Join explorer.hotelrecord hotelrecord_ On tour_hotel_.hotelcode = hotelrecord_.hotelref Where booking_record_.bookingdate Not Like '0000-00-00' And booking_record_.tourdeparturedate Not Like '0000-00-00' And hotelrecord_.hotelgroup = "LPL" And Year(booking_record_.tourdeparturedate) Between Year(AddDate(Now(), Interval -5 Year)) And Year(Now()) My MySQL skills are certainly not up to scratch, the actual result set I wish to find is "a customer who has been to 5 or more LPL hotels in the past 5 years". So far I havent got as far as dealing with the count as I'm getting a huge number of results with some 250+ per customer. I assume this is to do with the way I'm joining tables. Schema wise the booking_record table contains a tour reference code, which links to tour_hotel which then contains a hotelcode which links to hotelrecord. This hotelrecord table contains the hotelgroup. The client table is joined to the booking_record via a booking reference and a client may have many bookings. If anyone could suggest a way for me to do this I'd be very grateful and hopefully learn enough to do it myself next time! I've been scratching my head over this one for a few hours now! Customers may have many bookings within booking_record Daniel.

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  • Python's asyncore to periodically send data using a variable timeout. Is there a better way?

    - by Nick Sonneveld
    I wanted to write a server that a client could connect to and receive periodic updates without having to poll. The problem I have experienced with asyncore is that if you do not return true when dispatcher.writable() is called, you have to wait until after the asyncore.loop has timed out (default is 30s). The two ways I have tried to work around this is 1) reduce timeout to a low value or 2) query connections for when they will next update and generate an adequate timeout value. However if you refer to 'Select Law' in 'man 2 select_tut', it states, "You should always try to use select() without a timeout." Is there a better way to do this? Twisted maybe? I wanted to try and avoid extra threads. I'll include the variable timeout example here: #!/usr/bin/python import time import socket import asyncore # in seconds UPDATE_PERIOD = 4.0 class Channel(asyncore.dispatcher): def __init__(self, sock, sck_map): asyncore.dispatcher.__init__(self, sock=sock, map=sck_map) self.last_update = 0.0 # should update immediately self.send_buf = '' self.recv_buf = '' def writable(self): return len(self.send_buf) > 0 def handle_write(self): nbytes = self.send(self.send_buf) self.send_buf = self.send_buf[nbytes:] def handle_read(self): print 'read' print 'recv:', self.recv(4096) def handle_close(self): print 'close' self.close() # added for variable timeout def update(self): if time.time() >= self.next_update(): self.send_buf += 'hello %f\n'%(time.time()) self.last_update = time.time() def next_update(self): return self.last_update + UPDATE_PERIOD class Server(asyncore.dispatcher): def __init__(self, port, sck_map): asyncore.dispatcher.__init__(self, map=sck_map) self.port = port self.sck_map = sck_map self.create_socket(socket.AF_INET, socket.SOCK_STREAM) self.bind( ("", port)) self.listen(16) print "listening on port", self.port def handle_accept(self): (conn, addr) = self.accept() Channel(sock=conn, sck_map=self.sck_map) # added for variable timeout def update(self): pass def next_update(self): return None sck_map = {} server = Server(9090, sck_map) while True: next_update = time.time() + 30.0 for c in sck_map.values(): c.update() # <-- fill write buffers n = c.next_update() #print 'n:',n if n is not None: next_update = min(next_update, n) _timeout = max(0.1, next_update - time.time()) asyncore.loop(timeout=_timeout, count=1, map=sck_map)

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  • EasyHook Windows Hooking problem/.dll injection

    - by Tom
    Ok can someone try and find the error with this code, it should produce all the registry keys every time something accesses them but i keep getting: System.MissingMethodException: The given method does not exist at EasyHook.LocalHook.GetProcAdress(String InModule, String InChannelName) An example code can be found here: http://www.codeproject.com/KB/DLL/EasyHook64.aspx I can get the CcreateFileW example to work! My code is here: public class Main : EasyHook.IEntryPoint { FileMon.FileMonInterface Interface; LocalHook LocalHook; Stack<String> Queue = new Stack<String>(); public Main(RemoteHooking.IContext InContext,String InChannelName) { // connect to host... Interface = RemoteHooking.IpcConnectClient<FileMon.FileMonInterface>(InChannelName); Interface.Ping(); } public void Run(RemoteHooking.IContext InContext,String InChannelName) { // install hook... try { LocalHook localHook = LocalHook.Create(LocalHook.GetProcAddress("Advapi32.dll", "RegOpenKeyExW"),new DMyRegOpenKeyExW(MyRegOpenKeyExW),this); localHook.ThreadACL.SetExclusiveACL(new int[] { }); } catch (Exception ExtInfo) { Interface.ReportException(ExtInfo); return; } Interface.IsInstalled(RemoteHooking.GetCurrentProcessId()); RemoteHooking.WakeUpProcess(); // wait for host process termination... try { while (true) { Thread.Sleep(500); // transmit newly monitored file accesses... if (Queue.Count > 0) { String[] Package = null; lock (Queue) { Package = Queue.ToArray(); Queue.Clear(); } Interface.OnCreateFile(RemoteHooking.GetCurrentProcessId(), Package); } else Interface.Ping(); } } catch { // Ping() will raise an exception if host is unreachable } } [DllImport("Advapi32.dll", CharSet = CharSet.Unicode, SetLastError = true, CallingConvention = CallingConvention.StdCall)] static extern int RegOpenKeyExW(UIntPtr hKey,string subKey,int ulOptions,int samDesired,out UIntPtr hkResult); [UnmanagedFunctionPointer(CallingConvention.StdCall, CharSet = CharSet.Unicode, SetLastError = true)] delegate int DMyRegOpenKeyExW(UIntPtr hKey,string subKey,int ulOptions,int samDesired,out UIntPtr hkResult); int MyRegOpenKeyExW(UIntPtr hKey,string subKey,int ulOptions,int samDesired,out UIntPtr hkResult) { Console.WriteLine(string.Format("Accessing: {0}", subKey)); return RegOpenKeyExW(hKey, subKey, ulOptions, samDesired, out hkResult); } }

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  • Using complex where clause in NHibernate mapping layer

    - by JLevett
    I've used where clauses previously in the mapping layer to prevent certain records from ever getting into my application at the lowest level possible. (Mainly to prevent having to re-write lots of lines of code to filter out the unwanted records) These have been simple, one column queries, like so this.Where("Invisible = 0"); However a scenario has appeared which requires the use of an exists sql query. exists (select ep_.Id from [Warehouse].[dbo].EventPart ep_ where Id = ep_.EventId and ep_.DataType = 4 In the above case I would usually reference the parent table Event with a short name, i.e. event_.Id however as Nhibernate generates these short names dynamically it's impossible to know what it's going to be. So instead I tried using just Id, from above ep_ where Id = ep_.EventId When the code is run, because of the dynamic short names the EventPart table short name ep_ is has another short name prefixed to it, event0_.ep_ where event0_ refers to the parent table. This causes an SQL error because of the . in between event0_ and ep_ So in my EventMap I have the following this.Where("(exists (select ep_.Id from [isnapshot.Warehouse].[dbo].EventPart ep_ where Id = ep_.EventId and ep_.DataType = 4)"); but when it's generated it creates this select cast(count(*) as INT) as col_0_0_ from [isnapshot.Warehouse].[dbo].Event event0_ where (exists (select ep_.Id from [isnapshot.Warehouse].[dbo].EventPart event0_.ep_ where event0_.Id = ep_.EventId and ep_.DataType = 4) It has correctly added the event0_ to the Id Was the mapping layer where clause built to handle this and if so where am I going wrong?

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  • Create a new delegate class for each asynchronous image download?

    - by Charles S.
    First, I'm using an NSURLConnection to download JSON data from twitter. Then, I'm using a second NSURLConnection to download corresponding user avatar images (the urls to the images are parsed from the first data download). For the first data connection, I have my TwitterViewController set as the NSURLConnection delegate. I've created a separate class (ImageDownloadDelegate) to function as the delegate for a second NSURLConnection that handles the images. After the tweets are finished downloading, I'm using this code to get the avatars: for(int j=0; j<[self.tweets count]; j++){ ImageDownloadDelegate *imgDelegate = [[ImageDownloadDelegate alloc] init]; Tweet *myTweet = [self.tweets objectAtIndex:j]; imgDelegate.tweet = myTweet; imgDelegate.table = timeline; NSURLRequest* request = [NSURLRequest requestWithURL:[NSURL URLWithString:myTweet.imageURL] cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60]; imgConnection = [[NSURLConnection alloc] initWithRequest:request delegate:imgDelegate]; [imgDelegate release]; } So basically a new instance of the delegate class is created for each image that needs to be downloaded. Is this the best way to go about this? But then there's no way to figure out which image is associate with which tweet, correct? The algorithm works fine... I'm just wondering if I'm going about it the most efficient way.

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  • For each <item> in CheckedListBox. <item> returns as Object and not as Control

    - by Tivie
    Hello there. I have a CheckedListBox previously populated. I want to loop with a "for each / next" through all items in the CheckedListBox and do a lot of "stuff" with each iteration element of the checkedlistbox. example code: For Each item In CheckedListBox1.Items If item.Checked = True Then 'do stuff like item.BackColor = Color.Blue Else 'do other stuff item.BackColor = Color.Brown End If Next the problem is that is an 'Object' type and not a 'Control' type. If I force the iteration var As CheckBox, it throws an InvalidCastException saying that type 'System.String' can't be associated with type 'System.Windows.Forms.CheckBox' I know I can easily work around using for i=0 to CheckedListBox.Items.Count - 1 but I want to use a for each /next loop since I have a lot of code in that loop (and With can't be used) and always poiting directly to the object is something I wish to avoid and I really need the code to be as simple as possible. I actually spent one afternoon looking for this but couldn't find any answer. If someone could be kind enough to enlight me in this, it would be extremely appreciated. Best regards

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  • How can I convert seconds to minutes in jQuery while updating an element with the current time?

    - by pghtech
    So I see a number of ways to display allot of seconds in a (static) hr/min/sec. However, I am trying to produce a visual count down timer: $('#someelement').html(minCounter + ' minutes ' + ((secCounter == 0) ? '' : (secCounter + ' seconds'))); My counter is reduced inside a SetInterval that triggers ever 1 second: //....... var counter = redirectTimer; jQuery('#WarningDialogMsg').html(minCounter + ' minutes ' + ((secCounter == 0) ? '' : (secCounter + ' seconds'))); //........ SetInternval( function() { counter -= 1; secCounter = Math.floor(counter % 60); minCounter = Math.floor(counter / 60); //....... $('#someelement').html(minCounter + ' minutes ' + ((secCounter == 0) ? '' : (secCounter + ' seconds'))); }, 1000) It is a two minute counter but I don't want to display 120 seconds. I want to display 1 : 59 (and counting down). I have managed to get it to work using the above, but my main question is: is there a more elegant way to accomplish the above? (note: I am redirecting once "counter == 0").

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