Search Results

Search found 9771 results on 391 pages for 'equivalence classes'.

Page 356/391 | < Previous Page | 352 353 354 355 356 357 358 359 360 361 362 363  | Next Page >

• how much time does grid.py take to run ?

  - by trinity

  Hello all , I am using libsvm for binary classification.. I wanted to try grid.py , as it is said to improve results.. I ran this script for five files in separate terminals , and the script has been running for more than 12 hours.. this is the state of my 5 terminals now : [root@localhost tools]# python grid.py sarts_nonarts_feat.txt>grid_arts.txt Warning: empty z range [61.3997:61.3997], adjusting to [60.7857:62.0137] line 2: warning: Cannot contour non grid data. Please use "set dgrid3d". Warning: empty z range [61.3997:61.3997], adjusting to [60.7857:62.0137] line 4: warning: Cannot contour non grid data. Please use "set dgrid3d". [root@localhost tools]# python grid.py sgames_nongames_feat.txt>grid_games.txt Warning: empty z range [64.5867:64.5867], adjusting to [63.9408:65.2326] line 2: warning: Cannot contour non grid data. Please use "set dgrid3d". Warning: empty z range [64.5867:64.5867], adjusting to [63.9408:65.2326] line 4: warning: Cannot contour non grid data. Please use "set dgrid3d". [root@localhost tools]# python grid.py sref_nonref_feat.txt>grid_ref.txt Warning: empty z range [62.4602:62.4602], adjusting to [61.8356:63.0848] line 2: warning: Cannot contour non grid data. Please use "set dgrid3d". Warning: empty z range [62.4602:62.4602], adjusting to [61.8356:63.0848] line 4: warning: Cannot contour non grid data. Please use "set dgrid3d". [root@localhost tools]# python grid.py sbiz_nonbiz_feat.txt>grid_biz.txt Warning: empty z range [67.9762:67.9762], adjusting to [67.2964:68.656] line 2: warning: Cannot contour non grid data. Please use "set dgrid3d". Warning: empty z range [67.9762:67.9762], adjusting to [67.2964:68.656] line 4: warning: Cannot contour non grid data. Please use "set dgrid3d". [root@localhost tools]# python grid.py snews_nonnews_feat.txt>grid_news.txt Wrong input format at line 494 Traceback (most recent call last): File "grid.py", line 223, in run if rate is None: raise "get no rate" TypeError: exceptions must be classes or instances, not str I had redirected the outputs to files , but those files for now contain nothing.. And , the following files were created : sbiz_nonbiz_feat.txt.out sbiz_nonbiz_feat.txt.png sarts_nonarts_feat.txt.out sarts_nonarts_feat.txt.png sgames_nongames_feat.txt.out sgames_nongames_feat.txt.png sref_nonref_feat.txt.out sref_nonref_feat.txt.png snews_nonnews_feat.txt.out (-- is empty ) There's just one line of information in .out files.. the ".png" files are some GNU PLOTS . But i dont understand what the above GNUplots / warnings convey .. Should i re-run them ? Can anyone please tell me on how much time this script might take if each input file contains about 144000 lines.. Thanks and regards

  Read the article

• How to order a HasMany collection by a child property with Fluent NHibernate mapping

  - by Geoff Hardy

  I am using Fluent NHibernate to map the following classes: public abstract class DomainObject { public virtual int Id { get; protected internal set; } } public class Attribute { public virtual string Name { get; set; } } public class AttributeRule { public virtual Attribute Attribute { get; set; } public virtual Station Station { get; set; } public virtual RuleTypeId RuleTypeId { get; set; } } public class Station : DomainObject { public virtual IList<AttributeRule> AttributeRules { get; set; } public Station() { AttributeRules = new List<AttributeRule>(); } } My Fluent NHibernate mappings look like this: public class AttributeMap : ClassMap<Attribute> { public AttributeMap() { Id(o => o.Id); Map(o => o.Name); } } public class AttributeRuleMap : ClassMap<AttributeRule> { public AttributeRuleMap() { Id(o => o.Id); Map(o => o.RuleTypeId); References(o => o.Attribute).Fetch.Join(); References(o => o.Station); } } public class StationMap : ClassMap<Station> { public StationMap() { Id(o => o.Id); HasMany(o => o.AttributeRules).Inverse(); } } I would like to order the AttributeRules list on Station by the Attribute.Name property, but doing the following does not work: HasMany(o => o.AttributeRules).Inverse().OrderBy("Attribute.Name"); I have not found a way to do this yet in the mappings. I could create a IQuery or ICriteria to do this for me, but ideally I would just like to have the AttributeRules list sorted when I ask for it. Any advice on how to do this mapping?

  Read the article

• How do we, as a community, help encourage programming in public schools? (Or state Schools for the U

  - by NoMoreZealots

  PRIMARY MOTIVATION My office gets involved with the "First Robotics" competitions and one thing that lingers year to year is the students typically have no preparation for doing even simple programming as part of the public schools system. While the science classes provide some basic grasp of mechanical and electrical concepts, by in large computer programming gets no coverage from the curriculum. (This my be different in other areas of the country/world.) What makes it worse is there is only a short period of time you have to prepare the student's and help them design the robot. Talking to some professors from local colleges, it's a problem because you can't assume even the most basic understanding for freshman CS majors. Languages like Python, Lua and BASIC are simple enough for at least high school level students, if not younger. SCOPE So how do you get public schools to support a programming, at least to the level of "Try it in BASIC" examples that used to be at the end of a chapter in my Algebra book? At least enough to prepare them for event's such as the FIRST Robotic competitions. Which the primary objectives are to teach problem solving and team work, and to possible foster an interest in Math, Science and Engineering in general. (Not force feed to them, as some people her seem to be implying.) Edit: Why teach kids: (Since 2000 CS enrollment in US colleges has decreased by 70% while college enrollment has increased, this is a PROBLEM.) Saying there is no value in teaching someone programming in Jr./High school because they might think "they know programming." Is like saying there's no value in teaching High school science and physics, because they might decide they "know physics." Leading to abuse like: "I passed a high school physics class, I'm going to develop a Unified Quantum Gravitational Theory." Better Prepared students are better students. Instead it would allows college programs to raise the bar on the entry level courses, allowing students to be weeded out based on their understanding of more advanced material. Plus people who did poorly in that in topic in High school aren't as likely to say "I think there's money in computer's so I'll computer science." Plus if people take it in high school and decide THEN that it's not for them, it's better than them wasting their money to PAY a college to figure that out. The result is that people who take the degree are more likely to succeed and be there for the RIGHT reasons. (i.e. It's what they REALLY want to do. And that's REALLY the key to being good at anything.) Programming is like anything else, the more practice and genuine interest you have the better you get. If you start them later, they get less practice. The earlier give them the opportunity to start, the more practice they will get. All other things equal, the more practice the better the programmer.

  Read the article

• IF Statement has strange behavior

  - by BSchlinker

  I've developed a 'custom' cout, so that I can display text to console and also print it to a log file. This cout class is passed a different integer on initialization, with the integer representing the verbosity level of the message. If the current verbosity level is greater then or equal to the verbosity level of the message, the message should print. The problem is, I have messages printing even when the current verbosity level is too low. I went ahead and debugged it, expecting to find the problem. Instead, I found multiple scenarios where my if statements are not working as expected. The statement if(ilralevel_passed <= ilralevel_set) will sometimes proceed even if ilralevel_set is LESS then ilralevel_passed. You can see this behavior in the following picture (my apologizes for using Twitpic) http://twitpic.com/1xtx4g/full. Notice how ilralevel_set is equal to zero, and ilralevel_passed is equal to one. Yet, the if statement has returned true and is now moving forward to pass the line to cout. I've never seen this type of behavior before and I'm not exactly sure how to proceed debugging it. I'm not able to isolate the behavior either -- it only occurs in certain parts of my program. Any suggestions are appreciated as always. // Here is an example use of the function: // ilra_status << setfill('0') << setw(2) << dispatchtime.tm_sec << endl; // ilra_warning << "Dispatch time (seconds): " << mktime(&dispatchtime) << endl; // Here is the 'custom' cout function: #ifndef ILRA_H_ #define ILRA_H_ // System libraries #include <iostream> #include <ostream> #include <sstream> #include <iomanip> // Definitions #define ilra_talk ilra(__FUNCTION__,0) #define ilra_update ilra(__FUNCTION__,0) #define ilra_error ilra(__FUNCTION__,1) #define ilra_warning ilra(__FUNCTION__,2) #define ilra_status ilra(__FUNCTION__,3) // Statics static int ilralevel_set = 0; static int ilralevel_passed; // Classes class ilra { public: // constructor / destructor ilra(const std::string &funcName, int toset) { ilralevel_passed = toset; } ~ilra(){}; // enable / disable irla functions static void ilra_verbose_level(int toset){ ilralevel_set = toset; } // output template <class T> ilra &operator<<(const T &v) { if(ilralevel_passed <= ilralevel_set) std::cout << v; return *this; } ilra &operator<<(std::ostream&(*f)(std::ostream&)) { if(ilralevel_passed <= ilralevel_set) std::cout << *f; return *this; } }; // end of the class #endif /* ILRA_H_ */

  Read the article

• FluentNHibernate Many-To-One References where Foreign Key is not to Primary Key and column names are

  - by Todd Langdon

  I've been sitting here for an hour trying to figure this out... I've got 2 tables (abbreviated): CREATE TABLE TRUST ( TRUSTID NUMBER NOT NULL, ACCTNBR VARCHAR(25) NOT NULL ) CONSTRAINT TRUST_PK PRIMARY KEY (TRUSTID) CREATE TABLE ACCOUNTHISTORY ( ID NUMBER NOT NULL, ACCOUNTNUMBER VARCHAR(25) NOT NULL, TRANSAMT NUMBER(38,2) NOT NULL POSTINGDATE DATE NOT NULL ) CONSTRAINT ACCOUNTHISTORY_PK PRIMARY KEY (ID) I have 2 classes that essentially mirror these: public class Trust { public virtual int Id {get; set;} public virtual string AccountNumber { get; set; } } public class AccountHistory { public virtual int Id { get; set; } public virtual Trust Trust {get; set;} public virtual DateTime PostingDate { get; set; } public virtual decimal IncomeAmount { get; set; } } How do I do the many-to-one mapping in FluentNHibernate to get the AccountHistory to have a Trust? Specifically, since it is related on a different column than the Trust primary key of TRUSTID and the column it is referencing is also named differently (ACCTNBR vs. ACCOUNTNUMBER)???? Here's what I have so far - how do I do the References on the AccountHistoryMap to Trust??? public class TrustMap : ClassMap<Trust> { public TrustMap() { Table("TRUST"); Id(x => x.Id).Column("TRUSTID"); Map(x => x.AccountNumber).Column("ACCTNBR"); } } public class AccountHistoryMap : ClassMap<AccountHistory> { public AccountHistoryMap() { Table("TRUSTACCTGHISTORY"); Id (x=>x.Id).Column("ID"); References<Trust>(x => x.Trust).Column("ACCOUNTNUMBER").ForeignKey("ACCTNBR").Fetch.Join(); Map(x => x.PostingDate).Column("POSTINGDATE"); ); I've tried a few different variations of the above line but can't get anything to work - it pulls back AccountHistory data and a proxy for the Trust; however it says no Trust row with given identifier. This has to be something simple. Anyone? Thanks in advance.

  Read the article

• WPF binding behaviour different when bound property is declared as interface vs class type?

  - by Jay

  This started with weird behaviour that I thought was tied to my implementation of ToString(), and I asked this question: http://stackoverflow.com/questions/2916068/why-wont-wpf-databindings-show-text-when-tostring-has-a-collaborating-object It turns out to have nothing to do with collaborators and is reproducible. When I bind Label.Content to a property of the DataContext that is declared as an interface type, ToString() is called on the runtime object and the label displays the result. When I bind TextBlock.Text to the same property, ToString() is never called and nothing is displayed. But, if I change the declared property to a concrete implementation of the interface, it works as expected. Is this somehow by design? If so, any idea why? To reproduce: Create a new WPF Application (.NET 3.5 SP1) Add the following classes: public interface IFoo { string foo_part1 { get; set; } string foo_part2 { get; set; } } public class Foo : IFoo { public string foo_part1 { get; set; } public string foo_part2 { get; set; } public override string ToString() { return foo_part1 + " - " + foo_part2; } } public class Bar { public IFoo foo { get { return new Foo {foo_part1 = "first", foo_part2 = "second"}; } } } Set the XAML of Window1 to: <Window x:Class="WpfApplication1.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="Window1" Height="300" Width="300"> <StackPanel> <Label Content="{Binding foo, Mode=Default}"/> <TextBlock Text="{Binding foo, Mode=Default}"/> </StackPanel> </Window> in Window1.xaml.cs: public partial class Window1 : Window { public Window1() { InitializeComponent(); DataContext = new Bar(); } } When you run this application, you'll see the text only once (at the top, in the label). If you change the type of foo property on Bar class to Foo (instead of IFoo) and run the application again, you'll see the text in both controls.

  Read the article

• Hibernate mapping to object that already exists

  - by teehoo

  I have two classes, ServiceType and ServiceRequest. Every ServiceRequest must specify what kind of ServiceType it is. All ServiceType's are predefined in the database, and ServiceRequest is created at runtime by the client. Here are my .hbm files: <hibernate-mapping> <class dynamic-insert="false" dynamic-update="false" mutable="true" name="xxx.model.entity.ServiceRequest" optimistic-lock="version" polymorphism="implicit" select-before-update="false"> <id column="USER_ID" name="id"> <generator class="native"/> </id> <property name="quantity"> <column name="quantity" not-null="true"/> </property> <many-to-one cascade="all" class="xxx.model.entity.ServiceType" column="service_type" name="serviceType" not-null="false" unique="false"/> </class> </hibernate-mapping> and <hibernate-mapping> <class dynamic-insert="false" dynamic-update="false" mutable="true" name="xxx.model.entity.ServiceType" optimistic-lock="version" polymorphism="implicit" select-before-update="false"> <id column="USER_ID" name="id"> <generator class="native"/> </id> <property name="description"> <column name="description" not-null="false"/> </property> <property name="cost"> <column name="cost" not-null="true"/> </property> <property name="enabled"> <column name="enabled" not-null="true"/> </property> </class> </hibernate-mapping> When I run this, I get com.mysql.jdbc.exceptions.MySQLIntegrityConstraintViolationException: Cannot add or update a child row: a foreign key constraint fails I think my problem is that when I create a new ServiceRequest object, ServiceType is one of its properties, and therefore when I'm saving ServiceRequest to the database, Hibernate attempts to insert the ServiceType object once again, and finds that it is already exists. If this is the case, how do I make it so that Hibernate points to the exists ServiceType instead of trying to insert it again?

  Read the article

• LsaAddAccountRights not working for me

  - by SteveL

  Using: Delphi 2010 and the JEDI Windows API and JWSCL I am trying to assign the Logon As A Service privilege to a user using LsaAddAccountRights function but it does not work ie. after the function returns, checking in Group Policy Editor shows that the user still does not have the above mentioned privilege. I'm running the application on Windows XP. Would be glad if someone could point out what is wrong in my code: unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls, JwaWindows, JwsclSid; type TForm1 = class(TForm) Button1: TButton; procedure Button1Click(Sender: TObject); private { Private declarations } public { Public declarations } end; var Form1: TForm1; implementation {$R *.dfm} function AddPrivilegeToAccount(AAccountName, APrivilege: String): DWORD; var lStatus: TNTStatus; lObjectAttributes: TLsaObjectAttributes; lPolicyHandle: TLsaHandle; lPrivilege: TLsaUnicodeString; lSid: PSID; lSidLen: DWORD; lTmpDomain: String; lTmpDomainLen: DWORD; lTmpSidNameUse: TSidNameUse; lPrivilegeWStr: String; begin ZeroMemory(@lObjectAttributes, SizeOf(lObjectAttributes)); lStatus := LsaOpenPolicy(nil, lObjectAttributes, POLICY_LOOKUP_NAMES, lPolicyHandle); if lStatus <> STATUS_SUCCESS then begin Result := LsaNtStatusToWinError(lStatus); Exit; end; try lTmpDomainLen := DNLEN; // In 'clear code' this should be get by LookupAccountName SetLength(lTmpDomain, lTmpDomainLen); lSidLen := SECURITY_MAX_SID_SIZE; GetMem(lSid, lSidLen); try if LookupAccountName(nil, PChar(AAccountName), lSid, lSidLen, PChar(lTmpDomain), lTmpDomainLen, lTmpSidNameUse) then begin lPrivilegeWStr := APrivilege; lPrivilege.Buffer := PChar(lPrivilegeWStr); lPrivilege.Length := Length(lPrivilegeWStr) * SizeOf(Char); lPrivilege.MaximumLength := lPrivilege.Length; lStatus := LsaAddAccountRights(lPolicyHandle, lSid, @lPrivilege, 1); Result := LsaNtStatusToWinError(lStatus); end else Result := GetLastError; finally FreeMem(lSid); end; finally LsaClose(lPolicyHandle); end; end; procedure TForm1.Button1Click(Sender: TObject); begin AddPrivilegeToAccount('Sam', 'SeServiceLogonRight'); end; end. Thanks in advance.

  Read the article

• Container item implementation

  - by onurozcelik

  Hi, I am working in Train Traffic Controller software project. My responsibility in this project is to develop the visual railroad GUI. We are implementing the project with Qt. By now I am using QGraphicsLinearLayout to hold my items. I am using the layout because I do not want to calculate coordinates of each item. So far I wrote item classes to add the layout. For instance SwitchItem class symbolizes railroad switch in real world. Each item class is responsible for its own painting and events. So far so good. Now I need a composite item that can contain two or more item. This class is going to be responsible for painting the items contained in it. I need this class because I have to put two or more items inside same layout cell. If I don' t put them in same cell I can' t use layout. See the image below. BlockSegmentItem and SignalItem inside same cell. Here is my compositeitem implementation. #include "compositeitem.h" CompositeItem::CompositeItem(QString id,QList<FieldItem *> _children) { children = _children; } CompositeItem::~CompositeItem() { } QRectF CompositeItem::boundingRect() const { FieldItem *child; QRectF rect(0,0,0,0); foreach(child,children) { rect = rect.united(child->boundingRect()); } return rect; } void CompositeItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget ) { FieldItem *child; foreach(child,children) { child->paint(painter,option,widget); } } QSizeF CompositeItem::sizeHint(Qt::SizeHint which, const QSizeF &constraint) const { QSizeF itsSize(0,0); FieldItem *child; foreach(child,children) { // if its size empty set first child size to itsSize if(itsSize.isEmpty()) itsSize = child->sizeHint(Qt::PreferredSize); else { QSizeF childSize = child->sizeHint(Qt::PreferredSize); if(itsSize.width() < childSize.width()) itsSize.setWidth(childSize.width()); itsSize.setHeight(itsSize.height() + childSize.height()); } } return itsSize; } void CompositeItem::contextMenuEvent(QGraphicsSceneContextMenuEvent *event) { qDebug()<<"Test"; } This code works good with painting but when it comes to item events it is problematic. QGraphicsScene treats the composite item like a single item which is right for layout but not for events. Because each item has its own event implementation.(e.g. SignalItem has its special context menu event.) I have to handle item events seperately. Also I need a composite item implementation for the layout. How can I overcome this dilemma?

  Read the article

• Validating against a Schema with JAXB

  - by fwgx

  I've been looking for solutions to this problem for far too long considering how easy it sounds so I've come for some help. I have an XML Schema which I have used with xjc to create my JAXB binding. This works fine when the XML is well formed. Unfortunately it also doesn't complain when the XML is not well formed. I cannot figure out how to do proper full validation against the schema when I try to unmarshall an XML file. I have managed to use a ValidationEventCollector to handle events, which works for XML parsing errors such as mismatched tags but doesn't raise any events when there is a tag that is required but is completely absent. From what I have seen validation can be done againsta schema, but you must know the path to the schema in order to pass it into the setSchema() method. The problem I have is that the path to the schema is stored in the XML header and I can't knwo at run time where the schema is going to be. Which is why it's stored in the XML file: <?xml version="1.0" encoding="utf-8"?> <DDSSettings xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="/a/big/long/path/to/a/schema/file/DDSSettings.xsd"> <Field1>1</Field1> <Field2>-1</Field2> ...etc Every example I see uses setValidating(true), which is now deprecated, so throws an exception. This is the Java code I have so far, which seems to only do XML validation, not schema validation: try { JAXBContext jc = new JAXBContext() { private final JAXBContext jaxbContext = JAXBContext.newInstance("blah"); @Override public Unmarshaller createUnmarshaller() throws JAXBException { Unmarshaller unmarshaller = jaxbContext.createUnmarshaller(); ValidationEventCollector vec = new ValidationEventCollector() { @Override public boolean handleEvent(ValidationEvent event) throws RuntimeException { ValidationEventLocator vel = event.getLocator(); if (event.getSeverity() == event.ERROR || event.getSeverity() == event.FATAL_ERROR) { String error = "XML Validation Exception: " + event.getMessage() + " at row: " + vel.getLineNumber() + " column: " + vel.getColumnNumber(); System.out.println(error); } m_unmarshallingOk = false; return false; } }; unmarshaller.setEventHandler(vec); return unmarshaller; } @Override public Marshaller createMarshaller() throws JAXBException { throw new UnsupportedOperationException("Not supported yet."); } @Override @SuppressWarnings("deprecation") public Validator createValidator() throws JAXBException { throw new UnsupportedOperationException("Not supported yet."); } }; Unmarshaller unmarshaller = jc.createUnmarshaller(); m_ddsSettings = (com.ultra.DDSSettings)unmarshaller.unmarshal(new File(xmlfileName)); } catch (UnmarshalException ex) { Logger.getLogger(UniversalDomainParticipant.class.getName()).log( Level.SEVERE, null, ex); } catch (JAXBException ex) { Logger.getLogger(UniversalDomainParticipant.class.getName()).log( Level.SEVERE, null, ex); } So what is the proper way to do this validation? I was expecting there to be a validate() method on the JAXB generated classes, but I guess that would be too simple for Java.

  Read the article

• What's the best Scala build system?

  - by gatoatigrado

  I've seen questions about IDE's here -- Which is the best IDE for Scala development? and What is the current state of tooling for Scala?, but I've had mixed experiences with IDEs. Right now, I'm using the Eclipse IDE with the automatic workspace refresh option, and KDE 4's Kate as my text editor. Here are some of the problems I'd like to solve: use my own editor IDEs are really geared at everyone using their components. I like Kate better, but the refresh system is very annoying (it doesn't use inotify, rather, maybe a 10s polling interval). The reason I don't use the built-in text editor is because broken auto-complete functionalities cause the IDE to hang for maybe 10s. rebuild only modified files The Eclipse build system is broken. It doesn't know when to rebuild classes. I find myself almost half of the time going to project-clean. Worse, it seems even after it has finished building my project, a few minutes later it will pop up with some bizarre error (edit - these errors appear to be things that were previously solved with a project clean, but then come back up...). Finally, setting "Preferences / Continue launch if project contains errors" to "prompt" seems to have no effect for Scala projects (i.e. it always launches even if there are errors). build customization I can use the "nightly" release, but I'll want to modify and use my own Scala builds, not the compiler that's built into the IDE's plugin. It would also be nice to pass [e.g.] -Xprint:jvm to the compiler (to print out lowered code). fast compiling Though Eclipse doesn't always build right, it does seem snappy -- even more so than fsc. I looked at Ant and Maven, though haven't employed either yet (I'll also need to spend time solving #3 and #4). I wanted to see if anyone has other suggestions before I spend time getting a suboptimal build system working. Thanks in advance! UPDATE - I'm now using Maven, passing a project as a compiler plugin to it. It seems fast enough; I'm not sure what kind of jar caching Maven does. A current repository for Scala 2.8.0 is available [link]. The archetypes are very cool, and cross-platform support seems very good. However, about compile issues, I'm not sure if fsc is actually fixed, or my project is stable enough (e.g. class names aren't changing) -- running it manually doesn't bother me as much. If you'd like to see an example, feel free to browse the pom.xml files I'm using [github]. UPDATE 2 - from benchmarks I've seen, Daniel Spiewak is right that buildr's faster than Maven (and, if one is doing incremental changes, Maven's 10 second latency gets annoying), so if one can craft a compatible build file, then it's probably worth it...

  Read the article

• How can I make the C# compiler infer these type parameters automatically?

  - by John Feminella

  I have some code that looks like the following. First I have some domain classes and some special comparators for them. public class Fruit { public int Calories { get; set; } public string Name { get; set; } } public class FruitEqualityComparer : IEqualityComparer<Fruit> { // ... } public class BasketEqualityComparer : IEqualityComparer<IEnumerable<Fruit>> { // ... } Next, I have a helper class called ConstraintChecker. It has a simple BaseEquals method that makes sure some simple base cases are considered: public static class ConstraintChecker { public static bool BaseEquals(T lhs, T rhs) { bool sameObject = l == r; bool leftNull = l == null; bool rightNull = r == null; return sameObject && !leftNull && !rightNull; } There's also a SemanticEquals method which is just a BaseEquals check and a comparator function that you specify. public static bool SemanticEquals<T>(T lhs, T rhs, Func<T, T, bool> f) { return BaseEquals(lhs, rhs) && f(lhs, rhs); } And finally there's a SemanticSequenceEquals method which accepts two IEnumerable<T> instances to compare, and an IEqualityComparer instance that will get called on each pair of elements in the list via Enumerable.SequenceEquals. public static bool SemanticSequenceEquals<T, U, V>(U lhs, U rhs, V comparator) where U : IEnumerable<T> where V : IEqualityComparer<T> { return SemanticEquals(lhs, rhs, (l, r) => lhs.SequenceEqual(rhs, comparator)); } } // end of ConstraintChecker The point of SemanticSequenceEquals is that you don't have to define two comparators whenever you want to compare both IEnumerable<T> and T instances; now you can just specify an IEqualityComparer<T> and it will also handle lists when you invoke SemanticSequenceEquals. So I could get rid of the BasketEqualityComparer class, which would be nice. But there's a problem. The C# compiler can't figure out the types involved when you invoke SemanticSequenceEquals: return ConstraintChecker.SemanticSequenceEquals(lhs, rhs, new FruitEqualityComparer()); If I specify them explicitly, it works: return ConstraintChecker.SemanticSequenceEquals< Fruit, IEnumerable<Fruit>, IEqualityComparer<Fruit> > (lhs, rhs, new FruitEqualityComparer()); What can I change here so that I don't have to write the type parameters explicitly?

  Read the article

• Unlocking a mutex from a different thread (C++)

  - by dan

  I'm using the C++ boost::thread library, which in my case means I'm using pthreads. Officially, a mutex must be unlocked from the same thread which locks it, and I want the effect of being able to lock in one thread and then unlock in another. There are many ways to accomplish this. One possibility would be to write a new mutex class which allows this behavior. For example: class inter_thread_mutex{ bool locked; boost::mutex mx; boost::condition_variable cv; public: void lock(){ boost::unique_lock<boost::mutex> lck(mx); while(locked) cv.wait(lck); locked=true; } void unlock(){ { boost::lock_guard<boost::mutex> lck(mx); if(!locked) error(); locked=false; } cv.notify_one(); } // bool try_lock(); void error(); etc. } I should point out that the above code doesn't guarantee FIFO access, since if one thread calls lock() while another calls unlock(), this first thread may acquire the lock ahead of other threads which are waiting. (Come to think of it, the boost::thread documentation doesn't appear to make any explicit scheduling guarantees for either mutexes or condition variables). But let's just ignore that (and any other bugs) for now. My question is, if I decide to go this route, would I be able to use such a mutex as a model for the boost Lockable concept. For example, would anything go wrong if I use a boost::unique_lock< inter_thread_mutex for RAII-style access, and then pass this lock to boost::condition_variable_any.wait(), etc. On one hand I don't see why not. On the other hand, "I don't see why not" is usually a very bad way of determining whether something will work. The reason I ask is that if it turns out that I have to write wrapper classes for RAII locks and condition variables and whatever else, then I'd rather just find some other way to achieve the same effect.

  Read the article

• Adding NavigationControl to a TabBar Application containing UITableViews

  - by kungfuslippers

  Hi, I'm new to iPhone dev and wanted to get advice on the general design pattern / guide for putting a certain kind of app together. I'm trying to build a TabBar type application. One of the tabs needs to display a TableView and selecting a cell from within the table view will do something else - maybe show another table view or a web page. I need a Navigation Bar to be able to take me back from the table view/web page. The approach I've taken so far is to: Create an app based around UITabBarController as the rootcontroller i.e. @interface MyAppDelegate : NSObject <UIApplicationDelegate> { IBOutlet UIWindow *window; IBOutlet UITabBarController *rootController; } Create a load of UIViewController derived classes and associated NIBs and wire everything up in IB so when I run the app I get the basic tabs working. I then take the UIViewController derived class and modify it to the following: @interface MyViewController : UIViewController<UITableViewDataSource, UITableViewDelegate> { } and I add the delegate methods to the implementation of MyViewController - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { return 2; } - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @"Cell"; UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; if (cell == nil) { cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease]; } if (indexPath.row == 0) { cell.textLabel.text = @"Mummy"; } else { cell.textLabel.text = @"Daddy"; } return cell; } Go back to IB , open MyViewController.xib and drop a UITableView onto it. Set the Files Owner to be MyViewController and then set the delegate and datasource of the UITableView to be MyViewController. If I run the app now, I get the table view appearing with mummy and daddy working nicely. So far so good. The question is how do I go about incorporating a Navigation Bar into my current code for when I implement: - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath() { // get row selected NSUInteger row = [indexPath row]; if (row == 0) { // Show another table } else if (row == 1) { // Show a web view } } Do I drop a NavigationBar UI control onto MyControllerView.xib ? Should I create it programmatically? Should I be using a UINavigationController somewhere ? I've tried dropping a NavigationBar onto my MyControllerView.xib in IB but its not shown when I run the app, only the TableView is displayed.

  Read the article

• array data taking XML value is not taking css value in as3

  - by Sagar S. Ranpise

  I have xml structure all data comes here inside CDATA I am using css file in it to format text and classes are mentioned in xml Below is the code which shows data but does not format with CSS. Thanks in advance! var myXML:XML = new XML(); var myURLLoader:URLLoader = new URLLoader(); var myURLRequest:URLRequest = new URLRequest("test.xml"); myURLLoader.load(myURLRequest); //////////////For CSS/////////////// var myCSS:StyleSheet = new StyleSheet(); var myCSSURLLoader:URLLoader = new URLLoader(); var myCSSURLRequest:URLRequest = new URLRequest("test.css"); myCSSURLLoader.load(myCSSURLRequest); myCSSURLLoader.addEventListener(Event.COMPLETE,processXML); var i:int; var textHeight:int = 0; var textPadding:int = 10; var txtName:TextField = new TextField(); var myMov:MovieClip = new MovieClip(); var myMovGroup:MovieClip = new MovieClip(); var myArray:Array = new Array(); function processXML(e:Event):void { myXML = new XML(myURLLoader.data); trace(myXML.person.length()); var total:int = myXML.person.length(); trace("total" + total); for(i=0; i<total; i++) { myArray.push({name: myXML.person[i].name.toString()}); trace(myArray[i].name); } processCSS(); } function processCSS():void { myCSS.parseCSS(myCSSURLLoader.data); for(i=0; i<myXML.person.length(); i++) { myMov.addChild(textConvertion(myArray[i].name)); myMov.y = textHeight; textHeight += myMov.height + textPadding; trace("Text: "+myXML.person[i].name); myMovGroup.addChild(myMov); } this.addChild(myMovGroup); } function textConvertion(textConverted:String) { var tc:TextField = new TextField(); tc.htmlText = textConverted; tc.multiline = true; tc.wordWrap = true; tc.autoSize = TextFieldAutoSize.LEFT; tc.selectable = true; tc.y = textHeight; textHeight += tc.height + textPadding; tc.styleSheet = myCSS; return tc; }

  Read the article

• idiomatic property changed notification in scala?

  - by Jeremy Bell

  I'm trying to find a cleaner alternative (that is idiomatic to Scala) to the kind of thing you see with data-binding in WPF/silverlight data-binding - that is, implementing INotifyPropertyChanged. First, some background: In .Net WPF or silverlight applications, you have the concept of two-way data-binding (that is, binding the value of some element of the UI to a .net property of the DataContext in such a way that changes to the UI element affect the property, and vise versa. One way to enable this is to implement the INotifyPropertyChanged interface in your DataContext. Unfortunately, this introduces a lot of boilerplate code for any property you add to the "ModelView" type. Here is how it might look in Scala: trait IDrawable extends INotifyPropertyChanged { protected var drawOrder : Int = 0 def DrawOrder : Int = drawOrder def DrawOrder_=(value : Int) { if(drawOrder != value) { drawOrder = value OnPropertyChanged("DrawOrder") } } protected var visible : Boolean = true def Visible : Boolean = visible def Visible_=(value: Boolean) = { if(visible != value) { visible = value OnPropertyChanged("Visible") } } def Mutate() : Unit = { if(Visible) { DrawOrder += 1 // Should trigger the PropertyChanged "Event" of INotifyPropertyChanged trait } } } For the sake of space, let's assume the INotifyPropertyChanged type is a trait that manages a list of callbacks of type (AnyRef, String) = Unit, and that OnPropertyChanged is a method that invokes all those callbacks, passing "this" as the AnyRef, and the passed-in String). This would just be an event in C#. You can immediately see the problem: that's a ton of boilerplate code for just two properties. I've always wanted to write something like this instead: trait IDrawable { val Visible = new ObservableProperty[Boolean]('Visible, true) val DrawOrder = new ObservableProperty[Int]('DrawOrder, 0) def Mutate() : Unit = { if(Visible) { DrawOrder += 1 // Should trigger the PropertyChanged "Event" of ObservableProperty class } } } I know that I can easily write it like this, if ObservableProperty[T] has Value/Value_= methods (this is the method I'm using now): trait IDrawable { // on a side note, is there some way to get a Symbol representing the Visible field // on the following line, instead of hard-coding it in the ObservableProperty // constructor? val Visible = new ObservableProperty[Boolean]('Visible, true) val DrawOrder = new ObservableProperty[Int]('DrawOrder, 0) def Mutate() : Unit = { if(Visible.Value) { DrawOrder.Value += 1 } } } // given this implementation of ObservableProperty[T] in my library // note: IEvent, Event, and EventArgs are classes in my library for // handling lists of callbacks - they work similarly to events in C# class PropertyChangedEventArgs(val PropertyName: Symbol) extends EventArgs("") class ObservableProperty[T](val PropertyName: Symbol, private var value: T) { protected val propertyChanged = new Event[PropertyChangedEventArgs] def PropertyChanged: IEvent[PropertyChangedEventArgs] = propertyChanged def Value = value; def Value_=(value: T) { if(this.value != value) { this.value = value propertyChanged(this, new PropertyChangedEventArgs(PropertyName)) } } } But is there any way to implement the first version using implicits or some other feature/idiom of Scala to make ObservableProperty instances function as if they were regular "properties" in scala, without needing to call the Value methods? The only other thing I can think of is something like this, which is more verbose than either of the above two versions, but is still less verbose than the original: trait IDrawable { private val visible = new ObservableProperty[Boolean]('Visible, false) def Visible = visible.Value def Visible_=(value: Boolean): Unit = { visible.Value = value } private val drawOrder = new ObservableProperty[Int]('DrawOrder, 0) def DrawOrder = drawOrder.Value def DrawOrder_=(value: Int): Unit = { drawOrder.Value = value } def Mutate() : Unit = { if(Visible) { DrawOrder += 1 } } }

  Read the article

• Checking if an int is prime more efficiently

  - by SipSop

  I recently was part of a small java programming competition at my school. My partner and I have just finished our first pure oop class and most of the questions were out of our league so we settled on this one (and I am paraphrasing somewhat): "given an input integer n return the next int that is prime and its reverse is also prime for example if n = 18 your program should print 31" because 31 and 13 are both prime. Your .class file would then have a test case of all the possible numbers from 1-2,000,000,000 passed to it and it had to return the correct answer within 10 seconds to be considered valid. We found a solution but with larger test cases it would take longer than 10 seconds. I am fairly certain there is a way to move the range of looping from n,..2,000,000,000 down as the likely hood of needing to loop that far when n is a low number is small, but either way we broke the loop when a number is prime under both conditions is found. At first we were looping from 2,..n no matter how large it was then i remembered the rule about only looping to the square root of n. Any suggestions on how to make my program more efficient? I have had no classes dealing with complexity analysis of algorithms. Here is our attempt. public class P3 { public static void main(String[] args){ long loop = 2000000000; long n = Integer.parseInt(args[0]); for(long i = n; i<loop; i++) { String s = i +""; String r = ""; for(int j = s.length()-1; j>=0; j--) r = r + s.charAt(j); if(prime(i) && prime(Long.parseLong(r))) { System.out.println(i); break; } } System.out.println("#"); } public static boolean prime(long p){ for(int i = 2; i<(int)Math.sqrt(p); i++) { if(p%i==0) return false; } return true; } } ps sorry if i did the formatting for code wrong this is my first time posting here. Also the output had to have a '#' after each line thats what the line after the loop is about Thanks for any help you guys offer!!!

  Read the article

• How to initiate chatting between two clients and two clients only, using applets and servlets?

  - by mithun1538

  Hello everyone, I first need to apologize for my earlier questions. (You can check my profile for them)They seemed to ask more questions than give answers. Hence, I am laying down the actual question that started all them absurd questions. I am trying to design a chat applet. Till now, I have coded the applet, servlet and communication between the applet and the servlet. The code in the servlet side is such that I was able to establish chatting between clients using the applets, but the code was more like a broadcast all feature, i.e. all clients would be chatting with each other. That was my first objective when I started designing the chat applet. The second step is chatting between only two specific users, much like any other chat application we have. So this was my idea for it: I create an instance of the servlet that has the 'broadcast-all' code. I then pass the address of this instance to the respective clients. 2 client applets use the address to then chat. Technically the code is 'broadcast-all', but since only 2 clients are connected to it, it gives the chatting between two clients feature. Thus, groups of 2 clients have different instances of the same servlet, and each instance handles chatting between two clients at a max. However, as predicted, the idea didn't materialize! I tried to create an instance of the servlet but the only solution for that was using sessions on the servlet side, and I don't know how to use this session for later communications. I then tried to modify my broadcast-all code. In that code, I was using classes that implemented Observer and Observable interfaces. So the next idea that I got was: Create a new object of the Observable class(say class_1). This object be common to 2 clients. 2 clients that wish to chat will use same object of the class_1. 2 other clients will use a different object of class_1. But the problem here lies with the class that implements the Observer interface(say class_2). Since this has observers monitoring the same type of class, namely class_1, how do I establish an observer monitoring one object of class_1 and another observer monitoring another object of the same class class_1 (Because notifyObservers() would notify all the observers and I can't assign a particular observer to a particular object)? I first decided to ask individual problems, like how to create instances of servlets, using objects of observable and observer and so on in stackoverflow... but I got confused even more. Can anyone give me an idea how to establish chatting between two clients only?(I am using Http and not sockets or RMI). Regards, Mithun. P.S. Thanks to all who replied to my previous (absurd) queries. I should have stated the purpose earlier so that you guys could help me better.

  Read the article

• Android - Transforming widgets within transformed widgets and the resulting usability issues.

  - by Ben Rose

  Hello. I'm new to Android application development and I'm currently experimenting with various UI ideas. In the image below, you can see a vertically scrolling list of horizontally scrolling galleries (and also textviews as you can see). I'm also doing some matrix and camera transformations which I will come to in a minute. For the background of the list elements, I use green. Blue is the background of the galleries, and red is the background for the images. These are just for my benefit of learning. The galleries being used are extended classes where I overrode the drawChild method to perform a canvas scale operation in order for the image closest to the center (width) to be larger than the others. The list view going vertically, I overrode the drawChild method and used the camera rotations from lack of depth dimension in the canvas functionality. The items in the list are scaled down and rotated relative to their position's proximity to the center (height). I understood that scrolling and clicking would not necessarily follow along with the image transforms, but it appears as though the parent Gallery class's drawing is constrained to the original coordinates as well (see photo below). I would love to hear any insight any of you have regarding how I can change the coordinates of the galleries in what is rendered via gallery scroll and the touch responsiveness of said gallery. Images in the gallery are not same dimensions, so don't let that throw you in looking at the image below Thanks in advance! Ben link to image (could not embed) -- Update: I was using my test application UI and noticed that when I got the UI to the point of the linked image and then I touched the top portion of the next row in the list, the gallery updated to display the proper representation. So, I added a call to clearFocus() in the drawChild method and that resulted in more accurate drawing. It does seem a tad slower, and since I'm on the Incredible, I'm worried it is a bloated solution. In any event, I would still appreciate any thoughts you have regarding the best way to have the views display properly and how to translate the touch events in the gallery's new displayed area to its touchable coordinates so that scrolling on the actual images works when the gallery has moved. Thanks!

  Read the article

• When using delegates, need better way to do sequential processing

  - by Padawan

  I have a class WebServiceCaller that uses NSURLConnection to make asynchronous calls to a web service. The class provides a delegate property and when the web service call is done, it calls a method webServiceDoneWithXXX on the delegate. There are several web service methods that can be called, two of which are say GetSummary and GetList. The classes that use WebServiceCaller initially need both the summary and list so they are written like this: -(void)getAllData { [webServiceCaller getSummary]; } -(void)webServiceDoneWithGetSummary { [webServiceCaller getList]; } -(void)webServiceDoneWithGetList { ... } This works but there are at least two problems: The calls are split across delegate methods so it's hard to see the sequence at a glance but more important it's hard to control or modify the sequence. Sometimes I want to call just GetSummary and not also GetList so I would then have to use an ugly class-level state variable that tells webServiceDoneWithGetSummary whether to call GetList or not. Assume that GetList cannot be done until GetSummary completes and returns some data which is used as input to GetList. Is there a better way to handle this and still get asynchronous calls? Update based on Matt Long's answer: Using notifications instead of a delegate, it looks like I can solve problem #2 by setting a different selector depending on whether I want the full sequence (GetSummary+GetList) or just GetSummary. Both observers would still use the same notification name when calling GetSummary. I would have to write two separate methods to handle GetSummaryDone instead of using a single delegate method (where I would have needed some class-level variable to tell whether to then call GetList). -(void)getAllData { [[NSNotificationCenter defaultCenter] addObserver:self              selector:@selector(getSummaryDoneAndCallGetList:)                  name:kGetSummaryDidFinish object:nil];     [webServiceCaller getSummary]; } -(void)getSummaryDoneAndCallGetList { [NSNotificationCenter removeObserver] //process summary data [[NSNotificationCenter defaultCenter] addObserver:self              selector:@selector(getListDone:)                  name:kGetListDidFinish object:nil];     [webServiceCaller getList]; } -(void)getListDone { [NSNotificationCenter removeObserver] //process list data } -(void)getJustSummaryData { [[NSNotificationCenter defaultCenter] addObserver:self              selector:@selector(getJustSummaryDone:) //different selector but                  name:kGetSummaryDidFinish object:nil]; //same notification name     [webServiceCaller getSummary]; } -(void)getJustSummaryDone { [NSNotificationCenter removeObserver] //process summary data } I haven't actually tried this yet. It seems better than having state variables and if-then statements but you have to write more methods. I still don't see a solution for problem 1.

  Read the article

• UITableViewCell outlets not set during bundle load (possibly very elementary question)

  - by Jan Zich

  What are the most common reasons for an outlet (a class property) not being set during a bundle load? I'm sorry; most likely I'm not using the correct terms. It's my first steps with iPhone OS development and Objective-C, so please bear with me. Here is more details. Basically, I'm trying to create a table view based form with a fixed number of static rows. I followed this example: http://developer.apple.com/iphone/library/documentation/userexperience/conceptual/TableView_iPhone/TableViewCells/TableViewCells.html Scroll down to The Technique for Static Row Content please. I have one nib file with one table view, three table cells and all connections set as in the example. The problem is that the corresponding cell properties in my controller are never initialised. I get an exception in cellForRowAtIndexPath complaining that the returned cell is nil: UITableView dataSource must return a cell from tableView:cellForRowAtIndexPath. Here are the relevant parts from the implementation of the controller: @synthesize cellA; @synthesize cellB; @synthesize cellC; - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView { return 1; } - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { return 3; } - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { switch (indexPath.row) { case 0: return cellA; break; case 1: return cellB; break; case 2: return cellC; break; default: return nil; } } And here is the interface part: @interface AssociatePhoneViewController : UITableViewController { UITableViewCell *cellA; UITableViewCell *cellB; UITableViewCell *cellB; } @property (nonatomic, retain) IBOutlet UITableViewCell *cellA; @property (nonatomic, retain) IBOutlet UITableViewCell *cellB; @property (nonatomic, retain) IBOutlet UITableViewCell *cellC; @end This must be possibly one of the the most embarrassing questions on StackOverflow. It looks like the most basic example code. Is is possible that the cells are not instantiated with the nib file? I have them on the same level before the tabula view in the nib file. I tried to move them after the table view, but it did not make any difference. Are table cells in some way special? Do I need to set some flag or some property on them in the nib file? I was under the impression that all classes (views, windows, controllers …) listed in a nib file are simply instantiated (and linked using the provided connections). Could it possibly be some memory issue? The cell properties in my controller are not defined in any special way.

  Read the article

• Killing Mysql prcoesses staying in sleep command.

  - by Shino88

  Hey I am connecting a MYSQL database through hibernate and i seem to have processes that are not being killed after they are finished in the session. I have called flush and close on each session but when i check the server the last processes are still there with a sleep command. This is a new problem which i am having and was not the case yesterday. Is there any way i can ensure the killng of theses processes when i am done with a session. Below is an example of one of my classes. public JSONObject check() { //creates a new session needed to add elements to a database Session session = null; //holds the result of the check in the database JSONObject check = new JSONObject(); try{ //creates a new session needed to add elements to a database SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory(); session = sessionFactory.openSession(); if (justusername){ //query created to select a username from user table String hquery = "Select username from User user Where username = ? "; //query created Query query = session.createQuery(hquery); //sets the username of the query the values JSONObject contents query.setString(0, username); // executes query and adds username string variable String user = (String) query.uniqueResult(); //checks to see if result is found (null if not found) if (user == null) { //adds false to Jobject if not found check.put("indatabase", "false"); } else { check.put("indatabase", "true"); } //adds check to Jobject to say just to check username check.put("justusername", true); } else { //query created to select a username and password from user table String hquery = "Select username from User user Where username = :user and password = :pass "; Query query = session.createQuery(hquery); query.setString("user", username); query.setString("pass", password); String user = (String) query.uniqueResult(); if(user ==null) { check.put("indatabase", false); } else { check.put("indatabase", true); } check.put("justusername", false); } }catch(Exception e){ System.out.println(e.getMessage()); //logg.log(Level.WARNING, " Exception", e.getMessage()); }finally{ // Actual contact insertion will happen at this step session.flush(); session.close(); } //returns Jobject return check; }

  Read the article

• Executing a .NET Managed Assembly from SQL Server 2008 - Pro's, Con's & Recommendations

  - by RPM1984

  Hi guys, looking for opinions/recommendations/links for the following scenario im currently facing. The Platform: .NET 4.0 Web Application SQL Server 2008 The Task: Overhaul a component of the system that performs (fairly) complex mathematical operations based on a specific user activity, and updates numerous tables in the database. A common user activity might be "Bob" decides to post a forum topic. This results in (the end-solution) needing to look at various factors (about the post he did), then after doing some math based on lookup values/ratios as well as other data in the database, inserting some other data as a result of these operations. The Options: Ok - so here's what im thinking. Although it would be much easier to do this in C# (LINQ-SQL) it doesnt make much sense as the majority of the computations are based on values in the db, and it will get difficult to control/optimize/debug the LINQ over time. Hence, im leaning towards created a managed assembly (C# Class Library) that contains the lookup values (constants) as well as leveraging the math classes in the existing .NET BCL. Basically i'd expose a few methods that can be called by the T-SQL Stored Procedures. This to me has the following advantages: Simplicity of math. Do complex math in .NET vs complex math in T-SQL. No brainer. =) Abstraction of computatations, configurable "lookup" values and business logic from raw T-SQL. T-SQL only needs to care about the data, simplifying the stored procedures and making it easier to maintain. When it needs to do math it delegates off to the managed assembly. So, having said that - ive never done this before (call .NET assmembly from T-SQL), and after some googling the best site i could come up with is here, which is useful but outdated. So - what am i asking? Well, firstly - i need some better references on how to actually do this. "This" being how to call a C# .NET 4 Assembly from within T-SQL Stored Procedures in SQL Server 2008. Secondly, who out there has done this, what problems (if any) did you face? Realize this may be difficult to provide a "correct answer", so ill try to give it to whoever gives me the answer with a combination of good links and a list of pro's/con's/problems with this implementation. Cheers!

  Read the article

• Isn't the C++ standard library backward-compatible?

  - by Chris Metzler

  Hi. I'm working on a 64-bit Linux system, trying to build some code that depends on third-party libraries for which I have binaries. During linking, I get a stream of undefined reference errors for one of the libraries, indicating that the linker couldn't resolve references to standard C++ functions/classes, e.g.: librxio.a(EphReader.o): In function `gpstk::EphReader::read_fic_data(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)': EphReader.cpp:(.text+0x27c): undefined reference to `std::basic_ostream<char, std::char_traits<char> >& std::__ostream_insert<char, std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char const*, long)' EphReader.cpp:(.text+0x4e8): undefined reference to `std::basic_ostream<char, std::char_traits<char> >& std::__ostream_insert<char, std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char const*, long)' I'm not really a C++ programmer, but this looks to me like it can't find the standard library. Doing some more research, I got the following when I looked at librxio's dependency for the standard library: $ ldd librxio.so.16.0 ./librxio.so.16.0: /usr/lib64/libstdc++.so.6: version `GLIBCXX_3.4.9' not found (required by ./librxio.so.16.0) libm.so.6 => /lib64/libm.so.6 (0x00002aaaaad45000) libstdc++.so.6 => /usr/lib64/libstdc++.so.6 (0x00002aaaaafc8000) libgcc_s.so.1 => /lib64/libgcc_s.so.1 (0x00002aaaab2c8000) libc.so.6 => /lib64/libc.so.6 (0x00002aaaab4d7000) /lib64/ld-linux-x86-64.so.2 (0x0000555555554000) So I read that as saying that librxio (one of the third-party libraries) requires at least v3.4.9 of the standard library. But the version I have installed is 4.1.2: $ rpm -qa | grep libstdc compat-libstdc++-33-3.2.3-61.x86_64 libstdc++-devel-4.1.2-14.el5.i386 libstdc++-devel-4.1.2-14.el5.x86_64 libstdc++-4.1.2-14.el5.x86_64 libstdc++-4.1.2-14.el5.i386 Shouldn't this work? The shared object major number is 6, same as for v3.4.9. At this level, shouldn't this be backward compatible? It seems like the third-party library is looking for an earlier version of the standard library than what I have installed; but isn't there backward compatibility between versions with the same major number for the shared library? Again, I'm not really a C++ programmer; but I don't see what the problem is. Any advice greatly appreciated. Thanks.

  Read the article

• NHibernate : delete error

  - by MadSeb

  Hi, Model: I have a model in which one Installation can contain multiple "Computer Systems". Database: The table Installations has two columns Name and Description. The table ComputerSystems has three columsn Name, Description and InstallationId. Mappings: I have the following mapping for Installation: <?xml version="1.0" encoding="utf-8"?> <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="myProgram.Core" namespace="myProgram"> <class name="Installation" table="Installations" lazy="true"> <id name="Id" column="Id" type="int"> <generator class="native" /> </id> <property name="Name" column="Name" type="string" not-null="true" /> <property name="Description" column="Description" type="string" /> <bag name="ComputerSystems" inverse="true" lazy="true" cascade="all-delete-orphan"> <key column="InstallationId" /> <one-to-many class="ComputerSystem" /> </bag> </class> </hibernate-mapping> I have the following mapping for ComputerSystem: <?xml version="1.0" encoding="utf-8"?> <id name="Id" column="ID" type="int"> <generator class="native" /> </id> <property name="Name" column="Name" type="string" not-null="true" /> <property name="Description" column="Description" type="string" /> <many-to-one name="Installation" column="InstallationID" cascade="save-update" not-null="true" /> Classes: The Installation class is: public class Installation { public virtual String Description { get; set; } public virtual String Name { get; set; } public virtual IList<ComputerSystem> ComputerSystems { get { if (_computerSystemItems== null) { lock (this) { if (_computerSystemItems== null) _computerSystemItems= new List<ComputerSystem>(); } } return _computerSystemItems; } set { _computerSystemItems= value; } } protected IList<ComputerSystem> _computerSystemItems; public Installation() { Description = ""; Name= ""; } } The ComputerSystem class is: public class ComputerSystem { public virtual String Name { get; set; } public virtual String Description { get; set; } public virtual Installation Installation { get; set; } } The issue is that I get an error when trying to delete an installation that contains a ComputerSystem. The error is: "deleted object would be re-saved by cascade (remove deleted object from associations)". Can anyone help ? Regards, Seb

  Read the article

< Previous Page | 352 353 354 355 356 357 358 359 360 361 362 363  | Next Page >