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• How do I generate reports in R?

  - by Maiasaura

  I've been struggling for a week now trying to figure out how to generate reports in R using either Sweave or Brew. I should say right at the beginning that I have never used Tex before but I understand the logic of it. I have read this document several times. However, I cannot even get a simple example to parse. Brew successfully converts a simple markup file (just a title and some text) to a .tex file (no error). But it never ever converts tex to a pdf. > library(tools) > library(brew) > brew("population.brew", "population.tex") > texi2dvi("population.tex", pdf = TRUE) The last step always fails with: Error in texi2dvi("population.tex", pdf = TRUE) : Running 'texi2dvi' on 'population.tex' failed. What am I doing wrong? The report I am trying to build is fairly simple. I have 157 different analysis to summarize. Each one has 4 plots, 1 table and a summary. I just want output plot 1,2,3,4 output table \pagebreak ... that's it. Can anyone help me get further? I use osx, don't have Tex installed. thanks

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• Export Sharepoint 2007 Custom List as RSS File

  - by matt

  Here's our scenario: We've created a sharepoint 2007 calendar on our intranet site We want to run a daily job to export a subset of the events to an rss file Another job will move the rss file to our public web site We have some funny restrictions where we can't simply publish the rss feed to the public. We have to go this export route. I'm not clear on how to accomplish step 2. Ideally, we wouldn't have to write a lot of custom code to accomplish this. Thanks.

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• Why people are so afraid of using clone() (on collection and JDK classes) ?

  - by Bozho

  A number of times I've argued that using clone() isn't such a bad practice. Yes, I know the arguments. Bloch said it's bad. He indeed did, but he said that implementing clone() is bad. Using clone on the other hand, especially if it is implemented correctly by a trusted library, such as the JDK, is OK. Just yesterday I had a discussion about an answer of mine that merely suggests that using clone() for ArrayList is OK (and got no upvotes for that reason, I guess). If we look at the @author of ArrayList, we can see a familiar name - Josh Bloch. So clone() on ArrayList (and other collections) is perfectly fine. (Just look at the implementation). Same goes for Calendar and perhaps most of the java.lang and java.util classes. So, give me a reason why not to use clone() with JDK classes?

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• QSqlQuery UPDATE/INSERT DateTime with server's time (eg CURRENT_TIMESTAMP)

  - by Skinniest Man

  I am using QSqlQuery to insert data into a MySQL database. Currently all I care about is getting this to work with MySQL, but ideally I'd like to keep this as platform-independent as possible. What I'm after, in the context of MySQL, is to end up with code that effectively executes something like the following query: UPDATE table SET time_field=CURRENT_TIMESTAMP() WHERE id='5' The following code is what I have attempted, but it fails: QSqlQuery query; query.prepare("INSERT INTO table SET time_field=? WHERE id=?"); query.addBindValue("CURRENT_TIMESTAMP()"); query.addBindValue(5); query.exec(); The error I get is: Incorrect datetime value: 'CURRENT_TIMESTAMP()' for column 'time_field' at row 1 QMYSQL3: Unable to execute statement. I am not surprised as I assume Qt is doing some type checking when it binds values. I have dug through the Qt documentation as well as I know how, but I can't find anything in the API designed specifically for supporting MySQL's CURRENT_TIMESTAMP() function, or that of any other DBMS. Any suggestions?

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• Core Data Predicates with Subclassed NSManagedObjects

  - by coneybeare

  I have an AUDIO class. This audio has a SOUND_A subclass and a SOUND_B subclass. This is all done correctly and is working fine. I have another model, lets call it PLAYLIST_JOIN, and this can contain (in the real world) SOUND_A's and SOUND_B's, so we give it a relationship of AUDIO and PLAYLIST. This all works in the app. The problem I am having now is querying the PLAYLIST_JOIN table with an NSPredicate. What I want to do is find an exact PLAYLIST_JOIN item by giving it 2 keys in the predicate sound_a._sound_a_id = %@ && playlist.playlist_id = %@ and sound_b.sound_b_id = %@ && playlist.playlist_id = %@ The main problem is that because the table does not store sound_a and sound_b, but stored audio, I cannot use this syntax. I do not have the option of reorganizing the sound_a and sound_b to use the same _id attribute name, so how do I do this? Can I pass a method to the predicate? something like this: [audio getID] = %@ && playlist_id = %@

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• Oracle manually add an FK constraint

  - by Oxymoron

  Alright, since a client wants to automate a certain process, which includes creating a new key structure in a LIVE database, I need to create relations between tables.columns. Now I've found the tables ALL_CONS_COLS en USER_CONSTRAINTS to hold information about constraints. If I were to manually create constraints, by inserting into these tables, I should be able to recreate the original constraints. My question: are there any more tables I should look into? Do you have an alternate suggestions, as this sounds VERY dirty and error prone to begin with. Current modus operandi: Create a new column in each table for the PK; Generate a guid for this PK; Create a new column in each table for the FKs; Fetch the guid associated with the FK; ....... done sofar...... Add new constraint based on the old one; Remove old constraint; Rename new columns; This is kind of dodgy and I'd rather change my method, any ideas would be helpful. To put it different, client wants to change key structure from int to guid on a live database. What's the best way to approach this

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• Jquery Select Problem

  - by oraclee

  Hi; Jquery Code: $("[id$=mytable] tr").click(function() { alert($(this).html()); }); Html: <table id="mytable"> <tr> <td class="locked">1</td> <td>2</td> <td>3</td> </tr> <tr> <td class="locked">a</td> <td>b</td> <td>c</td> </tr> </table> i need only "td class='locked'" click return this click: <td class="locked">1</td> output: <tr> <td class="locked">1</td> <td>2</td> <td>3</td> </tr>

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• Changing the onClick area when adding an event

  - by Josh Breslow

  Is there anyway to change what a user clicks on to add an event? Right now the entire day is clickable. This becomes an issue when the user needs to put focus back on that window, requiring a mouse click. If they click on the calendar, which takes up most of the page, then they launch the "Add Event" function. Is there a way to have a Plus sign (+), or whatever symbol in each day that when clicked, launches the "Add Event" function? Or... Is there a way to have a button across the top that said, "Add Event"?

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• convert date error when retrieving data in twig page through doctrine

  - by user201892

  I just find this error when I retrieve all my records on twig page from the database through doctrine here is my twig code : {% extends "gestionConferenceApplicationBundle::layout.html.twig" %} {% block title "Hello " ~ name %} {% block content %} je suis un debutant <table border=2 > <th>Numéro</th> <th>Titre</th> <th>Ville</th> <th>Lieu</th> <th>Date de début</th> <th>Date de fin</th> {% for item in conferences %} <tr> <td>{{ item.id }}</td> <td>{{ item.titre }}</td> <td>{{ item.ville }}</td> <td>{{ item.lieu }}</td>* <td>{{ item.dateDebut }}</td> <td>{{ item.dateFin }}</td> </tr> {% endfor %} </table> {% endblock %} the error in the date : here it is : An exception has been thrown during the rendering of a template ("Catchable Fatal Error: Object of class DateTime could not be converted to string in C:\wamp\www\Symfony\app\cache\dev\twig\3c\dd\40a703549de9b8769fa40b82230e.php line 72") in gestionConferenceApplicationBundle:acceuil:acceuil.html.twig at line 19. do you have any idea how to convert this date or any other things in the MySql I have dateTime field and in doctrine I have : /** * @var \DateTime $dateDebut * * @ORM\Column(name="date_debut", type="datetime", nullable=false) */ private $dateDebut;

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• Help with mysql sum and group query and managing results for jquery graph.

  - by Scarface

  I have a system I am trying to design that will retrieve information from a database, so that it can be plotted in a jquery graph. I need to retrieve the information and somehow put it in the necessary coordinates format (for example two coordinates var d = [[1269417600000, 10],[1269504000000, 15]];). My table that I am selecting from is a table that stores user votes with fields: points_id (1=vote up, 2=vote down), user_id, timestamp, topic_id What I need to do is select all the votes and somehow group them into respective days and then sum the difference between 1 votes and 2 votes for each day. I then need to somehow display the data in the appropriate plotting format shown earlier. For example April 1, 4 votes. The data needs to be separated by commas, except the last plot entry, so I am not sure how to approach that. I showed an example below of the kind of thing I need but it is not correct, echo "var d=["; $query=mysql_query( "SELECT *, SUM(IF(points_id = \"1\", 1,0))-SUM(IF([points_id = \"2\", 1,0)) AS 'total' FROM points LEFT JOIN topic ON topic.topic_id=points.topic_id WHERE topic.creator='$user' GROUP by timestamp HAVING certain time interval" ); while ($row=mysql_fetch_assoc($query)){ $timestamp=$row['timestamp']; $votes=$row['total']; echo "[$timestamp,$vote],"; } echo "];";

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• SQLAlchemy Custom Type Which Contains Multiple Columns

  - by Kekoa

  I would like to represent a datatype as a single column in my model, but really the data will be stored in multiple columns in the database. I cannot find any good resources on how to do this in SQLAlchemy. I would like my model to look like this(this is a simplified example using geometry instead of my real problem which is harder to explain): class 3DLine(DeclarativeBase): start_point = Column(my.custom.3DPoint) end_point = Column(my.custom.3DPoint) This way I could assign an object with the (x, y, z) components of the point at once without setting them individually. If I had to separate each component, this could get ugly, especially if each class has several of these composite objects. I would combine the values into one encoded field except that I need to query each value separately at times. I was able to find out how to make custom types using a single column in the documentation. But there's no indication that I can map a single type to multiple columns. I suppose I could accomplish this by using a separate table, and each column would be a foreign key, but in my case I don't think it makes sense to have a one to one mapping for each point to a separate table, and this still does not give the ability to set the related values all at once.

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• Is it better to use a relational database or document-based database for an app like Wufoo?

  - by mboyle

  I'm working on an application that's similar to Wufoo in that it allows our users to create their own databases and collect/present records with auto generated forms and views. Since every user is creating a different schema (one user might have a database of their baseball card collection, another might have a database of their recipes) our current approach is using MySQL to create separate databases for every user with its own tables. So in other words, the databases our MySQL server contains look like: main-web-app-db (our web app containing tables for users account info, billing, etc) user_1_db (baseball_cards_table) user_2_db (recipes_table) .... And so on. If a user wants to set up a new database to keep track of their DVD collection, we'd do a "create database ..." with "create table ...". If they enter some data in and then decide they want to change a column we'd do an "alter table ....". Now, the further along I get with building this out the more it seems like MySQL is poorly suited to handling this. 1) My first concern is that switching databases every request, first to our main app's database for authentication etc, and then to the user's personal database, is going to be inefficient. 2) The second concern I have is that there's going to be a limit to the number of databases a single MySQL server can host. Pretending for a moment this application had 500,000 user databases, is MySQL designed to operate this way? What if it were a million, or more? 3) Lastly, is this method going to be a nightmare to support and scale? I've never heard of MySQL being used in this way so I do worry about how this affects things like replication and other methods of scaling. To me, it seems like MySQL wasn't built to be used in this way but what do I know. I've been looking at document-based databases like MongoDB, CouchDB, and Redis as alternatives because it seems like a schema-less approach to this particular problem makes a lot of sense. Can anyone offer some advice on this?

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• html doctype adds whitespace ??

  - by pstanton

  can someone please explain to me why having a doctype of <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> and <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"> render the following block differently under firefox? <table style="border-collapse:collapse; margin:0; padding:0;"> <tr> <td style="border:1px solid red; margin:0; padding:0;"><img src="http://images.smh.com.au/2010/06/01/1533814/th_park-90x60.jpg" style="border:none; padding:0; margin:0;" /></td> </tr> </table> using 'Transitional', there is no white space below the image, using 'Strict' there is! 2nd question, using strict, is it at all possible to remove this whitespace?

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• How do I DRY up business logic between sever-side Ruby and client-side Javascript?

  - by James A. Rosen

  I have a Widget model with inheritance (I'm using Single-Table Inheritance, but it's equally valid for Class-per-Table). Some of the subclasses require a particular field; others do not. class Widget < ActiveRecord ALL_WIDGET_TYPES = [FooWidget, BarWidget, BazWidget] end class FooWidget < Widget validates_presence_of :color end class BarWidget < Widget # no color field end class BazWidget < Widget validates_presence_of :color end I'm building a "New Widget" form (app/views/widgets/new.html.erb) and would like to dynamically show/hide the color field based on a <select> for widget_type. <% form_for @widget do |f| %> <%= f.select :type, Widget::ALL_WIDGET_TYPES %> <div class='hiddenUnlessWidgetTypeIsFooOrBaz'> <%= f.label :color %> <%= f.text_field :color %> </div> <% end %> I can easily write some jQuery to watch for onChange events on widget_type, but that would mean putting some sort of WidgetTypesThatRequireColor constant in my Javascript. Easy enough to do manually, but it is likely to get disconnected from the Widget model classes. I would prefer not to output Javascript directly in my view, though I have considered using content_for(:js) and have a yield :js in my template footer. Any better ideas?

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• All symbols after & stripped

  - by user300413

  My query: mysql::getInstance()->update('requests', array('response' => mysql_real_escape_string($_POST['status'])), array('secret' => $_POST['secret'])); ?> If i wand to add string with "&" symbol, all symbols after "&" stripped. Example: string: !"?;%:?*()_+!@#$%^&*()_+ in database i see only: !"?;%:?*()_+!@#$%^ How to fix this? update function, if anyone need: function update($table, $updateList, $whereConditions) { $updateQuery = ''; foreach ($updateList as $key => $newValue) { if (!is_numeric($newValue)) { $newValue = "'" . $newValue . "'"; } if (strlen($updateQuery) == 0) { $updateQuery .= '`' . $key . '` = ' . $newValue; } else { $updateQuery .= ', `' . $key . '` = ' . $newValue; } } return $this->query('UPDATE ' . $table . ' SET ' . $updateQuery . $this->buildWhereClause($whereConditions)); }

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• iOS layout; I'm not getting it

  - by Tbee

  Well, "not getting it" is too harsh; I've got it working in for what for me is a logical setup, but it does not seem to be what iOS deems logical. So I'm not getting something. Suppose I've got an app that shows two pieces of information; a date and a table. According to the MVC approach I've got three MVC at work here, one for the date, one for the table and one that takes both these MCVs and makes it into a screen, wiring them up. The master MVC knows how/where it wants to layout the two sub MVC's. Each detail MVC only takes care of its own childeren within the bounds that were specified by the master MVC. Something like: - (void)loadView { MVC* mvc1 = [[MVC1 alloc] initwithFrame:...] [self.view addSubview:mvc1.view]; MVC* mvc2 = [[MVC2 alloc] initwithFrame:...] [self.view addSubview:mvc2.view]; } If the above is logical (which is it for me) then I would expect any MVC class to have a constructor "initWithFrame". But an MVC does not, only view have this. Why? How would one correctly layout nested MVCs? (Naturally I do not have just these two, but the detail MVCs have sub MVCs again.)

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• How to paginate json data?

  - by Pandiya Chendur

  I used json data and iterated div elements to get my result.... function Iteratejsondata(HfJsonValue) { //var jsonObj = eval('(' + HfJsonValue + ')'); var jsonObj = JSON.parse(HfJsonValue); for (var i = jsonObj.Table.length - 1; i >= 0; i--) { var employee = jsonObj.Table[i]; $('<div class="resultsdiv"><br /><span class="resultName">' + employee.Emp_Name + '</span><span class="resultfields" style="padding-left:100px;">Category&nbsp;:</span>&nbsp;<span class="resultfieldvalues">' + employee.Desig_Name + '</span><br /><br /><span id="SalaryBasis" class="resultfields">Salary Basis&nbsp;:</span>&nbsp;<span class="resultfieldvalues">' + employee.SalaryBasis + '</span><span class="resultfields" style="padding-left:25px;">Salary&nbsp;:</span>&nbsp;<span class="resultfieldvalues">' + employee.FixedSalary + '</span><span style="font-size:110%;font-weight:bolder;padding-left:25px;">Address&nbsp;:</span>&nbsp;<span class="resultfieldvalues">' + employee.Address + '</span></div>').insertAfter('#ResultsDiv'); } $(".resultsdiv:even").addClass("resultseven"); $(".resultsdiv").hover(function() { $(this).addClass("resultshover"); }, function() { $(this).removeClass("resultshover"); }); } I get 22 records in total... Now i want to paginate these divs (i.e) 5 divs per page... Any suggestion...

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• How to correctly handle click events on Widget

  - by www.liveinternet.ruusersilya_bog

  There is a task to make smt like todo list on widget (with dinamic number of elements), how to organize this list for click support on this elements. I only found how add click event on one widget layout element (with setOnClickPendingIntent), and how send text to widget element TextView. But it's unclear how handle click events for sub-elemets, or how get click coordinates(or item) where was click event. I saw widget "Agenda widget" - and it work fine with clicking on different calendar rows. I will be very much appreciated for help.

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• Some questions about special operators i've never seen in C++ code.

  - by toto

  I have downloaded the Phoenix SDK June 2008 (Tools for compilers) and when I'm reading the code of the Hello sample, I really feel lost. public ref class Hello { //-------------------------------------------------------------------------- // // Description: // // Class Variables. // // Remarks: // // A normal compiler would have more flexible means for holding // on to all this information, but in our case it's simplest (if // somewhat inelegant) if we just keep references to all the // structures we'll need to access as classstatic variables. // //-------------------------------------------------------------------------- static Phx::ModuleUnit ^ module; static Phx::Targets::Runtimes::Runtime ^ runtime; static Phx::Targets::Architectures::Architecture ^ architecture; static Phx::Lifetime ^ lifetime; static Phx::Types::Table ^ typeTable; static Phx::Symbols::Table ^ symbolTable; static Phx::Phases::PhaseConfiguration ^ phaseConfiguration; 2 Questions : What's that ref keyword? What is that sign ^ ? What is it doing protected: virtual void Execute ( Phx::Unit ^ unit ) override; }; override is a C++ keyword too? It's colored as such in my Visual Studio. I really want to play with this framework, but this advanced C++ is really an obstacle right now. Thank you.

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• MYSQL JOIN WHERE ISSUES - need some kind of if condition

  - by Breezer

  Hi Well this will be hard to explain but ill do my best The thing is i have 4 tables all with a specific column to relate to eachother. 1 table with users(agent_users) , 1 with working hours(agent_pers), 1 with sold items(agent_stat),1 with project(agent_pro) the user and the project table is irrelevant in the issue at hand but to give you a better understanding why certain tables is included in my query i decided to still mention them =) The thing is that I use 2 pages to insert data to the working hour and the sold items during that time tables, then i have a third page to summarize everything for current month, the query for that is as following: SELECT *, SUM(sv_p_kom),SUM(sv_p_gick),SUM(sv_p_lunch) FROM (( agent_users LEFT JOIN agent_pers ON agent_users.sv_aid = agent_pers.sv_p_uid) LEFT JOIN agent_stat ON agent_pers.sv_p_uid = agent_stat.sv_s_uid) LEFT JOIN agent_pro ON agent_pers.sv_p_pid=agent_pro.p_id WHERE MONTH(agent_pers.sv_p_datum) =7 GROUP BY sv_aname so the problem is now that i dont want sold items from previous months to get included in the data received, i know i could solve that by simple adding in the WHERE part MONTH(agent_stat.sv_s_datum) =7 but then if no items been sold that month no data at all will show up not the time or anything. Any aid on how i could solve this is greatly appreciated. if there's something that's not so clear dont hesitate to ask and ill try my best to answer. after all my english isn't the best out there :P regards breezer

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• Conditional row count in linq to nhibernate doesn't work

  - by Lucasus

  I want to translate following simple sql query into Linq to NHibernate: SELECT NewsId ,sum(n.UserHits) as 'HitsNumber' ,sum(CASE WHEN n.UserHits > 0 THEN 1 ELSE 0 END) as 'VisitorsNumber' FROM UserNews n GROUP BY n.NewsId My simplified UserNews class: public class AktualnosciUzytkownik { public virtual int UserNewsId { get; set; } public virtual int UserHits { get; set; } public virtual User User { get; set; } // UserId key in db table public virtual News News { get; set; } // NewsId key in db table } I've written following linq query: var hitsPerNews = (from n in Session.Query<UserNews>() group n by n.News.NewsId into g select new { NewsId = g.Key, HitsNumber = g.Sum(x => x.UserHits), VisitorsNumber = g.Count(x => x.UserHits > 0) }).ToList(); But generated sql just ignores my x => x.UserHits > 0 statement and makes unnecessary 'left outer join': SELECT news1_.NewsId AS col_0_0_, CAST(SUM(news0_.UserHits) AS INT) AS col_1_0_, CAST(COUNT(*) AS INT) AS col_2_0_ FROM UserNews news0_ LEFT OUTER JOIN News news1_ ON news0_.NewsId=news1_.NewsId GROUP BY news1_.NewsId How Can I fix or workaround this issue? Maybe this can be done better with QueryOver syntax?

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• NHibernate's ISQLQuery returns instances that are of an unexpected type.

  - by Frederik Gheysels

  Hi all, I'm using NHibernate 2.1.2.400, and I'm having an issue with a an ISQLQuery query. The reason why I use an ISQLQuery here, is that this query uses a table for which I have no entity mapped in NHibernate. The query looks like this: ISQLQuery query = session.CreateSQLQuery ( "select p.*, price.* " + "from prestation p left outer join prestationprice price on p.PrestationId = price.PrestationId " + "where p.Id IN ( select id from prestationregistry where ..."); 'Prestationregistry' is the table that is not known by NHibernate (unmapped, so therefore the native SQL Query). my code continues like this: query.AddEntity ("p", typeof(Prestation)); query.AddJoin ("price", typeof(PrestationPrice)); query.SetResultTransformer (Transformers.DistinctRootEntity); var result = query.List(); So far so good. I expect that I'm given a list of 'Prestation' instances as a result of this query, since I declared 'Prestation' as being the root-object that has to be returned by the AddEntity method. I also expect that the PrestationPrices for each Prestation are eagerly loaded by this query (hence the AddJoin method). To my surprise, the List() method returns a collection of PrestationPrice instances instead of Prestation instances. How come ? Am I doing something wrong ? And if so, could you be so kind to tell me what I'm doing wrong ? Edit: Additional Info: When I debug, and put a watch on the 'query' instance, I can see that the queryReturns member of the query contains 2 items: - one NativeSqlQueryRootReturn instance who'se ReturnEntityName is 'Prestation' - one NativeSqlQueryJoinReturn When I do not specify the 'DistinctRootEntity' result transformer, the query returns instances of 'Prestation' instead of PrestationPrice. However, it contains multiple copies of the same instance.

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• Big-O for calculating all routes from GPS data

  - by HH

  A non-critical GPS module use lists because it needs to be modifiable, new routes added, new distances calculated, continuos comparisons. Well so I thought but my team member wrote something I am very hard to get into. His pseudo code int k =0; a[][] <- create mapModuleNearbyDotList -array //CPU O(n) for(j = 1 to n) // O(nlog(m)) for(i =1 to n) for(k = 1 to n) if(dot is nearby) adj[i][j]=min(adj[i][j], adj[i][k] + adj[k][j]); His ideas transformations of lists to tables His worst case time complexity is O(n^3), where n is number of elements in his so-called table. Exception to the last point with Finite structure: O(mlog(n)) where n is number of vertices and m is the amount of neighbour vertices. Questions about his ideas why to waste resources to transform constantly-modified lists to table? Fast? only point where I to some extent agree but cannot understand the same upper limits n for each for-loops -- perhaps he supposed it circular why does the code take O(mlog(n)) to proceed in time as finite structure? The term finite may be wrong, explicit?

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• Drupal 6 sign-up booking, reservation system with payments

  - by Lukasz

  Hi Guys. I have tried to find out the working solution for implementing simple events booking system in Drupal 6 (limited places, payment, signing up/buying few places for firends). System does not have to be big but easy to customize events to reserve/book places for. I was surprised of not finding much complete solutions. Most of the time I was directed to use modules like: Date, Calendar, Singup, Singup Ubercraft integration, Ubercraft. Does anybody of you has tested it? Is it working and customizable or you would suggest other alternatives on the subject? Wiil appreciate any recomendations.

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• Are there good reasons not to use an ORM?

  - by hangy

  During my apprenticeship, I have used NHibernate for some smaller projects which I mostly coded and designed on my own. Now, before starting some bigger project, the discussion arose how to design data access and whether or not to use an ORM layer. As I am still in my apprenticeship and still consider myself a beginner in enterprise programming, I did not really try to push in my opinion, which is that using an object relational mapper to the database can ease development quite a lot. The other coders in the development team are much more experienced than me, so I think I will just do what they say. :-) However, I do not completely understand two of the main reasons for not using NHibernate or a similar project: One can just build one’s own data access objects with SQL queries and copy those queries out of Microsoft SQL Server Management Studio. Debugging an ORM can be hard. So, of course I could just build my data access layer with a lot of SELECTs etc, but here I miss the advantage of automatic joins, lazy-loading proxy classes and a lower maintenance effort if a table gets a new column or a column gets renamed. (Updating numerous SELECT, INSERT and UPDATE queries vs. updating the mapping config and possibly refactoring the business classes and DTOs.) Also, using NHibernate you can run into unforeseen problems if you do not know the framework very well. That could be, for example, trusting the Table.hbm.xml where you set a string’s length to be automatically validated. However, I can also imagine similar bugs in a “simple” SqlConnection query based data access layer. Finally, are those arguments mentioned above really a good reason not to utilise an ORM for a non-trivial database based enterprise application? Are there probably other arguments they/I might have missed? (I should probably add that I think this is like the first “big” .NET/C# based application which will require teamwork. Good practices, which are seen as pretty normal on Stack Overflow, such as unit testing or continuous integration, are non-existing here up to now.)

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