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  • Properly populating tables in an Object Relational database

    - by chaosTechnician
    I've got a homework assignment that requires that I use Oracle 10g Express to implement an Object Relational database to track phone billing data. I have a superclass of Communications with subclasses of Call, Text, and Data. I'm hitting a snag with properly populating these tables so that I can find the appropriate data in the various tables. My Types and Tables are declared as such: create type CommunicationType as object ( -- column names here ) not final; create type CallType under CommunicationType ( -- column names here ); create type TextType under CommunicationType ( -- column names here ); create type DataType under CommunicationType ( -- column names here ); create table Communications of CommunicationType ( -- Primary and Foreign key constraints here ); create table Calls of CallType; create table Texts of TextType; create table Datas of DataType; When I try to insert data into one of the subclasses, its entry doesn't appear in the superclass. Likewise if I insert into the superclass, it doesn't show up in the appropriate subclass. For example, insert into Calls values (CallType( -- Values -- )); doesn't show any data in Communications. Nor does insert into Communications values (CallType( -- Values -- )); show anything in Calls. What am I doing wrong?

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  • What is the preferred way in C++ for converting a builtin type (int) to bool?

    - by Martin
    When programming with Visual C++, I think every developer is used to see the warning warning C4800: 'BOOL' : forcing value to bool 'true' or 'false' from time to time. The reason obviously is that BOOL is defined as int and directly assigning any of the built-in numerical types to bool is considered a bad idea. So my question is now, given any built-in numerical type (int, short, ...) that is to be interpreted as a boolean value, what is the/your preferred way of actually storing that value into a variable of type bool? Note: While mixing BOOL and bool is probably a bad idea, I think the problem will inevitably pop up whether on Windows or somewhere else, so I think this question is neither Visual-C++ nor Windows specific. Given int nBoolean; I prefer this style: bool b = nBoolean?true:false; The following might be alternatives: bool b = !!nBoolean; bool b = (nBoolean != 0); Is there a generally preferred way? Rationale? I should add: Since I only work with Visual-C++ I cannot really say if this is a VC++ specific question or if the same problem pops up with other compilers. So it would be interesting to specifically hear from g++ or users how they handle the int-bool case. Regarding Standard C++: As David Thornley notes in a comment, the C++ Standard does not require this behavior. In fact it seems to explicitly allow this, so one might consider this a VC++ weirdness. To quote the N3029 draft (which is what I have around atm.): 4.12 Boolean conversions [conv.bool] A prvalue of arithmetic, unscoped enumeration, pointer, or pointer to member type can be converted to a prvalue of type bool. A zero value, null pointer value, or null member pointer value is converted to false; any other value is converted to true. (...)

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  • .net runtime type casting when using reflection

    - by Mike
    I have need to cast a generic list of a concrete type to a generic list of an interface that the concrete types implement. This interface list is a property on an object and I am assigning the value using reflection. I only know the value at runtime. Below is a simple code example of what I am trying to accomplish: public void EmployeeTest() { IList<Employee> initialStaff = new List<Employee> { new Employee("John Smith"), new Employee("Jane Doe") }; Company testCompany = new Company("Acme Inc"); //testCompany.Staff = initialStaff; PropertyInfo staffProperty = testCompany.GetType().GetProperty("Staff"); staffProperty.SetValue(testCompany, (staffProperty.PropertyType)initialStaff, null); } Classes are defined like so: public class Company { private string _name; public string Name { get { return _name; } set { _name = value; } } private IList<IEmployee> _staff; public IList<IEmployee> Staff { get { return _staff; } set { _staff = value; } } public Company(string name) { _name = name; } } public class Employee : IEmployee { private string _name; public string Name { get { return _name; } set { _name = value; } } public Employee(string name) { _name = name; } } public interface IEmployee { string Name { get; set; } } Any thoughts? I am using .NET 4.0. Would the new covariant or contravariant features help? Thanks in advance.

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  • boost::spirit (qi) decision between float and double

    - by ChrisInked
    I have a parser which parses different data types from an input file. I already figured out, that spirit can decide between short and int, for example: value %= (shortIntNode | longIntNode); with shortIntNode %= (qi::short_ >> !qi::double_) [qi::_val = phoenix::bind(&CreateShortIntNode, qi::_1)]; longIntNode %= (qi::int_ >> !qi::double_) [qi::_val = phoenix::bind(&CreateLongIntNode, qi::_1)]; I used this type of rules to detect doubles as well (from the answers here and here). The parser was able to decide between int for numbers 65535 and short for numbers <= 65535. But, for float_ and double_ it does not work as expected. It just rounds these values to parse it into a float value, if there is a rule like this: value %= (floatNode | doubleFloatNode); with floatNode %= (qi::float_) [qi::_val = phoenix::bind(&CreateFloatNode, qi::_1)]; doubleFloatNode %= (qi::double_) [qi::_val = phoenix::bind(&CreateDoubleFloatNode, qi::_1)]; Do you know if there is something like an option or some other trick to decide between float_ and double_ depending on the data type range? Thank you very much!

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  • Machine leaning algorithm for data classification.

    - by twk
    Hi all, I'm looking for some guidance about which techniques/algorithms I should research to solve the following problem. I've currently got an algorithm that clusters similar-sounding mp3s using acoustic fingerprinting. In each cluster, I have all the different metadata (song/artist/album) for each file. For that cluster, I'd like to pick the "best" song/artist/album metadata that matches an existing row in my database, or if there is no best match, decide to insert a new row. For a cluster, there is generally some correct metadata, but individual files have many types of problems: Artist/songs are completely misnamed, or just slightly mispelled the artist/song/album is missing, but the rest of the information is there the song is actually a live recording, but only some of the files in the cluster are labeled as such. there may be very little metadata, in some cases just the file name, which might be artist - song.mp3, or artist - album - song.mp3, or another variation A simple voting algorithm works fairly well, but I'd like to have something I can train on a large set of data that might pick up more nuances than what I've got right now. Any links to papers or similar projects would be greatly appreciated. Thanks!

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  • Returning large collections from WCF Serivce

    - by Nate Bross
    I'm trying to determine the best approach for building a WCF Service, and the area I'm struggling with most is returning lists of objects. The built-in maxMessageSize of 64k seems pretty high, and I really don't want to bump it up (quick googling finds 100s of places bumping the maxMessageSize up to multi-gigabyte range which seems foolish). But, when I'm returning a collection of objects (~150 items) I am exceeding the default 64k. I'm almost to the point of returning my own class which inherits IEnumerable and has properties for hasNext, hasPrevious and PageSize so that I can implement paging on the client side -- this seems like alot of code. The other option is to jackup the maxMessageSize and hope for the best, but that feels wrong. All other aspects of my service are working great, its just returning large collectiosn where I'm having issues. For background, there are two types of consumers of this service, UI applications which will be primarly web and/or wpf applications, and data processing applications, .NET console apps, and maybe some other non-UI apps. For the UI applications, I would like to keep them responsive and keep the messageSize low, on the console apps it doesn't matter as much as they are just pulling data down to do processing and push it back up to the service.

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  • F# numeric associations

    - by b1g3ar5
    I have a numeric association for a custom type as follows: let DiffNumerics = { new INumeric<Diff> with member op.Zero = C 0.0 member op.One = C 1.0 member op.Add(a,b) = a + b member op.Subtract(a,b) = a - b member op.Multiply(a,b) = a * b member ops.Negate(a) = Diff.negate a member ops.Abs(a) = Diff.abs a member ops.Equals(a, b) = ((=) a b) member ops.Compare(a, b) = Diff.compare a b member ops.Sign(a) = int (Diff.sign a).Val member ops.ToString(x,fmt,fmtprovider) = failwith "not implemented" member ops.Parse(s,numstyle,fmtprovider) = failwith "not implemented" } GlobalAssociations.RegisterNumericAssociation(DiffNumerics) It works fine in f# interactive, but crashes when I run, because .ElementOps is not filled correctly for a matrix of these types. Any ideas why this might be? EDIT: In fsi, the code let A = dmatrix [[Diff.C 1.;Diff.C 2.;Diff.C 3.];[Diff.C 4.;Diff.C 5.;Diff.C 6.]] let B = matrix [[1.;2.;3.];[4.;5.;6.]] gives: > A.ElementOps;; val it : INumeric<Diff> = FSI_0003.NewAD+DiffNumerics@258 > B.ElementOps;; val it : INumeric<float> = Microsoft.FSharp.Math.Instances+FloatNumerics@115 > in the debugger A.ElementOps shows: '(A).ElementOps' threw an exception of type 'System.NotSupportedException' and, for the B matrix: Microsoft.FSharp.Math.Instances+FloatNumerics@115 So somehow the DiffNumerics isn't making it to the compiled program.

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  • database setup for web application

    - by vbNewbie
    I have an application that requires a database and I have already setup tables but not sure if they match the requirements of the app. The app is a crawler which fetches web urls, crawls and stores appropriate urls and posts and all this is based on client requests which are stored as projects. So for each url stored there is one post and for client there are many projects and for each project there are many types of requests. So we get a client with a request and assign them a project name and then use the request to search for content and store the url and post. A request could already exist and should not be duplicated but should be associated with the right client and project and post etc. Here is my schema now: url table: urlId PK queryId FK url post table: postId PK urlId FK post date request table: queryId PK request client table: clientId PK client Name projectId FK project table: projectID PK queryID FK project Does this look right? or does anyone have suggestions. Of course my stored procedures and insert statements will have to be in depth.

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  • How to define multiple elements in XML Schema with the same name and different attribute value allow

    - by David Skyba
    I would like to create XML Schema for this chunk of xml, I would like to restrict the values of "name" attribute, so that in output document on and only one instance of day is allowed for each week day: <a> <day name="monday" /> <day name="tuesday" /> <day name="wednesday" /> </a> I have tried to use this: <xs:complexType name="a"> <xs:sequence> <xs:element name="day" minOccurs="1" maxOccurs="1"> <xs:complexType> <xs:attribute name="name" use="required"> <xs:simpleType> <xs:restriction base="xs:string"> <xs:enumeration value="monday" /> </xs:restriction> </xs:simpleType> </xs:attribute> </xs:complexType> </xs:element> <xs:element name="day" minOccurs="1" maxOccurs="1"> <xs:complexType> <xs:attribute name="name" use="required"> <xs:simpleType> <xs:restriction base="xs:string"> <xs:enumeration value="tuesday" /> </xs:restriction> </xs:simpleType> </xs:attribute> </xs:complexType> </xs:element> </xs:sequence> </xs:complexType> but XML Schema validator in eclipse says error "Multiple elements with name 'day', with different types, appear in the model group.". Is there any other way?

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  • Facebook Stream.Get -- How to access data in array?

    - by user316841
    On stream.get, I try to echo $feeds["posts"][$i]["attachment"]["href"]; It return the URL, but, in the same array scope where "type" is located (which returns string: video, etc), trying $feeds["posts"][$i]["attachment"]["type"] returns nothing at all! Here's an array through PHP's var_dump: http://pastie.org/930475 So, from testing I suppose this is protected by Facebook? Does that makes sense at all? Here it's full: http://pastie.org/930490, but not all attachment/media/types has values. It's also strange, because I can't access through [attachment][media][href] or [attachment][media][type], and if I try [attachment][media][0][type] or href, it gives me a string offset error. ["attachment"]=> array(8) { ["media"]=> array(1) { [0]=> array(5) { ["href"]=> string(55) "http://www.facebook.com/video/video.php?v=1392999461587" ["alt"]=> string(13) "IN THE STUDIO" ["type"]=> string(5) "video" My question is, is this protected by Facebook? Or we can actually access this array position?

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  • How to store data in mysql, to get the fastest performance?

    - by Oden
    Hey, I'm thinking about it, witch of the following two query types would give me the fastest performance for a user messaging module inside my site: The first one i thought about is a multi table setup, witch has a connection table, and a main table. The connection table holds the connection between accounts, and the messaging table. In this case a query would look like following, to get some data of the author, and the messages he has sent: SELECT m.*, a.username FROM messages AS m LEFT JOIN connection_table ON (message_id = m.id) LEFT JOIN accounts AS a ON (account_id = a.id) WHERE m.id = '32341' Inserting into it is a little bit more "complicated". My other idea, and in my thought the better solution of this problem is that i store the data i would use in a connection table in the same table where is store the data of the mail. Sounds like i would get lots of duplicated entries, but no, because i have a field witch has text type and holds user ids like this: *24*32*249* If I want to query them, i use the mysql LIKE method. Deleting is an other problem, but for this i have one more field where i store who has deleted the post. Sad about that i don't know how to join this. So what would you recommend? Are there other ways?

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  • Extending the .NET type system so the compiler enforces semantic meaning of primitive values in cert

    - by Drew Noakes
    I'm working with geometry a bit at the moment and am converting a lot between degrees and radians. Unfortunately, both of these are represented by double, so there's compile time warning/error if I try to pass a value in degrees where radians are expected. I believe F# has a compile-time solution for this (called units of measure.) I'd like to do something similar in C#. As another example, imagine a SQL library that accepts various query parameters as strings. It'd be good to have a way of enforcing that only clean strings were allowed to be passed in at runtime, and the only way to get a clean string was to pass through some SQL injection attack preventing logic. The obvious solution is to wrap the double/string/whatever in a new type to give it the type information the compiler needs. I'm curious if anyone has an alternative solution. If you do think wrapping is the only/best way, then please go into some of the downsides of the pattern (and any upsides I haven't mentioned too.) I'm especially concerned about the performance of abstracted primitive numeric types on my calculations at runtime.

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  • Question about decorator pattern and the abstract decorator class?

    - by es11
    This question was asked already here, but rather than answering the specific question, descriptions of how the decorator pattern works were given instead. I'd like to ask it again because the answer is not immediately evident to me just by reading how the decorator pattern works (I've read the wikipedia article and the section in the book Head First Design Patterns). Basically, I want to know why an abstract decorator class must be created which implements (or extends) some interface (or abstract class). Why can't all the new "decorated classes" simply implement (or extend) the base abstract object themselves (instead of extending the abstract decorator class)? To make this more concrete I'll use the example from the design patterns book dealing with coffee beverages: There is an abstract component class called Beverage Simple beverage types such as HouseBlend simply extend Beverage To decorate beverage, an abstract CondimentDecorator class is created which extends Beverage and has an instance of Beverage Say we want to add a "milk" condiment, a class Milk is created which extends CondimentDecorator I'd like to understand why we needed the CondimentDecorator class and why the class Milk couldn't have simply extended the Beverage class itself and been passed an instance of Beverage in its constructor. Hopefully this is clear...if not I'd simply like to know why is the abstract decorator class necessary for this pattern? Thanks. Edit: I tried to implement this, omitting the abstract decorator class, and it seems to still work. Is this abstract class present in all descriptions of this pattern simply because it provides a standard interface for all of the new decorated classes?

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  • How do you manually set a RadioGroup value in wicket?

    - by Kane
    I'm trying to change the selected radio button in a Wicket RadioGroup during an AjaxEventBehavior but can't figure out how to do so. Specifically when a user types some text in a textbox I want to change the selected radio button to one I specify. How do you do this? Here's what I have so far (it crashes on addComponent): myRadioGroup = new RadioGroup("MyNewGroup", new PropertyModel(getPojo(), "selectedGroup")); Radio internalRadio = new Radio("InternalDirectoryNumber", new Model("Internal")); myRadioGroup .add(internalRadio); Radio externalRadio = new Radio("OtherMobileNumber", new Model("External")); myRadioGroup .add(externalRadio); TextField myTxtField= new TextField("TextBoxPrivateNumber", new PropertyModel(getVoiceItem(), "privateMobilePhone")); myTxtField.add( new AjaxEventBehavior( "onKeyUp" ) { @Override protected void onEvent(AjaxRequestTarget target) { Component component = target.getPage().get("myForm:MyNewGroup").setDefaultModelObject("External"); target.addComponent(component); //this causes an exception } }); myRadioGroup .add(myTxtField); Here is the exception that's thrown. java.lang.IllegalArgumentException: cannot update component that does not have setOutputMarkupId property set to true. Component: [MarkupContainer [Component id = myRadioGroup]] What's the proper way to do this? I'm not finding a whole lot of wicket documentation for this online.

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  • Could I do this blind relative to absolute path conversion (for perforce depot paths) better?

    - by wonderfulthunk
    I need to "blindly" (i.e. without access to the filesystem, in this case the source control server) convert some relative paths to absolute paths. So I'm playing with dotdots and indices. For those that are curious I have a log file produced by someone else's tool that sometimes outputs relative paths, and for performance reasons I don't want to access the source control server where the paths are located to check if they're valid and more easily convert them to their absolute path equivalents. I've gone through a number of (probably foolish) iterations trying to get it to work - mostly a few variations of iterating over the array of folders and trying delete_at(index) and delete_at(index-1) but my index kept incrementing while I was deleting elements of the array out from under myself, which didn't work for cases with multiple dotdots. Any tips on improving it in general or specifically the lack of non-consecutive dotdot support would be welcome. Currently this is working with my limited examples, but I think it could be improved. It can't handle non-consecutive '..' directories, and I am probably doing a lot of wasteful (and error-prone) things that I probably don't need to do because I'm a bit of a hack. I've found a lot of examples of converting other types of relative paths using other languages, but none of them seemed to fit my situation. These are my example paths that I need to convert, from: //depot/foo/../bar/single.c //depot/foo/docs/../../other/double.c //depot/foo/usr/bin/../../../else/more/triple.c to: //depot/bar/single.c //depot/other/double.c //depot/else/more/triple.c And my script: begin paths = File.open(ARGV[0]).readlines puts(paths) new_paths = Array.new paths.each { |path| folders = path.split('/') if ( folders.include?('..') ) num_dotdots = 0 first_dotdot = folders.index('..') last_dotdot = folders.rindex('..') folders.each { |item| if ( item == '..' ) num_dotdots += 1 end } if ( first_dotdot and ( num_dotdots > 0 ) ) # this might be redundant? folders.slice!(first_dotdot - num_dotdots..last_dotdot) # dependent on consecutive dotdots only end end folders.map! { |elem| if ( elem !~ /\n/ ) elem = elem + '/' else elem = elem end } new_paths << folders.to_s } puts(new_paths) end

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  • Unboxing to unknown type

    - by Robert
    I'm trying to figure out syntax that supports unboxing an integral type (short/int/long) to its intrinsic type, when the type itself is unknown. Here is a completely contrived example that demonstrates the concept: // Just a simple container that returns values as objects struct DataStruct { public short ShortVale; public int IntValue; public long LongValue; public object GetBoxedShortValue() { return LongValue; } public object GetBoxedIntValue() { return LongValue; } public object GetBoxedLongValue() { return LongValue; } } static void Main( string[] args ) { DataStruct data; // Initialize data - any value will do data.LongValue = data.IntValue = data.ShortVale = 42; DataStruct newData; // This works if you know the type you are expecting! newData.ShortVale = (short)data.GetBoxedShortValue(); newData.IntValue = (int)data.GetBoxedIntValue(); newData.LongValue = (long)data.GetBoxedLongValue(); // But what about when you don't know? newData.ShortVale = data.GetBoxedShortValue(); // error newData.IntValue = data.GetBoxedIntValue(); // error newData.LongValue = data.GetBoxedLongValue(); // error } In each case, the integral types are consistent, so there should be some form of syntax that says "the object contains a simple type of X, return that as X (even though I don't know what X is)". Because the objects ultimately come from the same source, there really can't be a mismatch (short != long). I apologize for the contrived example, it seemed like the best way to demonstrate the syntax. Thanks.

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  • LEFT OUTER JOIN with a WHERE clause

    - by Wesley
    I have two tables. indRailType contains a list of the names paired with an ID value that I use in other tables to indicate the rail type. WO_BreakerRail contains a date column and a rail code colume that corresponds to the same code in indRailType and some other data. There's a row in WO_BreakerRail for any activity on each rail type, for every date. So I could have 3 rows dated for 3/19/2010, each row indicates a different rail code, and what happened. When I use the following LEFT OUTER JOIN, I get a table with all the types of rail, with nulls in the rows where nothing happened on the 19th. Now, this is only working because I only have one date represented in my WO_BreakerRail table right now, the 19th. When I add more rows with different dates, things will go haywire. This is my SQL statement, which right now gives me exactly the results I want: SELECT WO_BreakerRail.ID, indRailType.RailType, WO_BreakerRail.CreatedPieces, WO_BreakerRail.OutsideSource, WO_BreakerRail.Charged, WO_BreakerRail.Rejected, WO_BreakerRail.RejectedToCrop FROM indRailType LEFT OUTER JOIN WO_BreakerRail ON indRailType.RailCode = WO_BreakerRail.RailCode Now, when I add in a WHERE WO_BreakerRail.Date = @Date clause I lose all the rows in the JOIN which nothing happened. I don't want that. From reading up, it sounds like a FULL OUTER JOIN is what I want, but SQL Server Compact Edition doesn't support FULL OUTER JOINs. Is there a way around this, or am I looking for something else entirely?

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  • Accept templated parameter of stl_container_type<string>::iterator

    - by Rodion Ingles
    I have a function where I have a container which holds strings (eg vector<string>, set<string>, list<string>) and, given a start iterator and an end iterator, go through the iterator range processing the strings. Currently the function is declared like this: template< typename ContainerIter> void ProcessStrings(ContainerIter begin, ContainerIter end); Now this will accept any type which conforms to the implicit interface of implementing operator*, prefix operator++ and whatever other calls are in the function body. What I really want to do is have a definition like the one below which explicitly restricts the amount of input (pseudocode warning): template< typename Container<string>::iterator> void ProcessStrings(Container<string>::iterator begin, Container<string>::iterator end); so that I can use it as such: vector<string> str_vec; list<string> str_list; set<SomeOtherClass> so_set; ProcessStrings(str_vec.begin(), str_vec.end()); // OK ProcessStrings(str_list.begin(), str_list.end()); //OK ProcessStrings(so_set.begin(), so_set.end()); // Error Essentially, what I am trying to do is restrict the function specification to make it obvious to a user of the function what it accepts and if the code fails to compile they get a message that they are using the wrong parameter types rather than something in the function body that XXX function could not be found for XXX class.

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  • Many to many table design question

    - by user169867
    Originally I had 2 tables in my DB, [Property] and [Employee]. Each employee can have 1 "Home Property" so the employee table has a HomePropertyID FK field to Property. Later I needed to model the situation where despite having only 1 "Home Property" the employee did work at or cover for multiple properties. So I created an [Employee2Property] table that has EmployeeID and PropertyID FK fields to model this many 2 many relationship. Now I find that I need to create other many-to-many relationships between employees and properties. For example if there are multiple employees that are managers for a property or multiple employees that perform maintenance work at a property, etc. My questions are: 1) Should I create seperate many-to-many tables for each of these situations or should I just create 1 more table like [PropertyAssociatonType] that lists the types of associations an emploee can have with a property and just add a FK field to [Employee2Property] such a PropertyAssociationTypeID that explains what the association is? I'm curious about the pros/cons or if there's another better way. 2) Am I stupid and going about this all worng? Thanks for any suggestions :)

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  • Function should return float, but it gets messed up!

    - by Andre
    Hi guys, I'm going crazy here. I have a function that should return a float number: - (float) getHue:(UIColor *)original { NSLog(@"getHue"); const CGFloat *componentColors = CGColorGetComponents(original.CGColor); float red = componentColors[0]; float green = componentColors[1]; float blue = componentColors[2]; float h = 0.0f; float maxChannel = fmax(red, fmax(green, blue)); float minChannel = fmin(red, fmin(green, blue)); if (maxChannel == minChannel) h = 0.0f; else if (maxChannel == red) h = 0.166667f * (green - blue) / (maxChannel - minChannel) + 0.000000f; else if (maxChannel == green) h = 0.166667f * (blue - red) / (maxChannel - minChannel) + 0.333333f; else if (maxChannel == blue) h = 0.166667f * (red - green) / (maxChannel - minChannel) + 0.666667f; else h = 0.0f; if (h < 0.0f) h += 1.0f; NSLog(@"getHue results: %f", h); return h; } The NSLog will trace it correctly (i.e: 0.005), but the actual return value of the function is NULL. I've tried getting that value in so many ways and it never works. float originalHue = [self getHue:original]; results in a building error, as it says: "incompatible types in initialization" float *originalHue = [self getHue:original]; results in a null return. I've tried other ways, but it never actually gets the value properly. Any thoughts? Cheers guys, Andre

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  • Simply doing modelType.ToString() isn't sufficient, How can i use it via Activator.CreateInstance?

    - by programmerist
    public class MyController { public object CreateByEnum(DataModelType modeltype) { string enumText = modeltype.ToString(); // will return for example "Company" Type classType = Type.GetType(enumText); // the Type for Company class object t = Activator.CreateInstance(classType); // create an instance of Company class return t; } } public class CompanyView { public static List<Personel> GetPersonel() { MyController controller = new MyController(); _Company company = controller.CreateByEnum(DataModelType.Company) as _Company; return company.GetPersonel(); } } public enum DataModelType { xyz, klm, tucyz, Company } Yes, I agree Activator.CreateInstance() is very useful. Unfortunately, I need to pass in the correct type. That means building the correct string to pass to Type.GetType(). If I trace through the call to Controller.CreatebyEnum() in the code I posted above, simply doing modelType.ToString() isn't sufficient, even for the case of DataModelType.Company. My solution'll be maintenance bottleneck. What would be better is something that takes the results of modelType.ToString() and then recursively searches through all the types found in all the assemblies loaded in the current AppDomain. According to MSDN, Type.GetType() only searches the current calling assembly, and mscorlib.dll. How can i do that? . i need best performance?

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  • Setting up Inversion of Control (IoC) in ASP.NET MVC with Castle Windsor

    - by Lirik
    I'm going over Sanderson's Pro ASP.NET MVC Framework and in Chapter 4 he discusses Creating a Custom Controller Factory and it seems that the original method, AddComponentLifeStyle or AddComponentWithLifeStyle, used to register controllers is deprecated now: public class WindsorControllerFactory : DefaultControllerFactory { IWindsorContainer container; public WindsorControllerFactory() { container = new WindsorContainer(new XmlInterpreter(new ConfigResource("castle"))); // register all the controller types as transient var controllerTypes = from t in Assembly.GetExecutingAssembly().GetTypes() where typeof(IController).IsAssignableFrom(t) select t; //[Obsolete("Use Register(Component.For<I>().ImplementedBy<T>().Named(key).Lifestyle.Is(lifestyle)) instead.")] //IWindsorContainer AddComponentLifeStyle<I, T>(string key, LifestyleType lifestyle) where T : class; foreach (Type t in controllerTypes) { container.Register(Component.For<IController>().ImplementedBy<???>().Named(t.FullName).LifeStyle.Is(LifestyleType.Transient)); } } // Constructs the controller instance needed to service each request protected override IController GetControllerInstance(Type controllerType) { return (IController)container.Resolve(controllerType); } } The new suggestion is to use Register(Component.For<I>().ImplementedBy<T>().Named(key).Lifestyle.Is(lifestyle)), but I can't figure out how to present the implementing controller type in the ImplementedBy<???>() method. I tried ImplementedBy<t>() and ImplementedBy<typeof(t)>(), but I can't find the appropriate way to pass int he implementing type. Any ideas?

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  • Array of templated structs

    - by Jakub Mertlik
    I have structs templated by int derived from a Base struct. struct Base { int i; double d; }; template< int N > struct Derv : base { static const int mN = N; }; I need to make an array of Derv< N where N can vary for each struct in that array. I know C/C++ does not allow arrays of objects of different types, but is there a way around this? I was thinking of separating the type information somehow (hints like pointers to Base struct or usage of union spring to my mind, but with all of these I don't know how to store the type information of each array element for usage DURING COMPILE TIME). As you can see, the memory pattern of each Derv< N is the same. I need to access the type of each array element for template specialization later in my code. The general aim of this all is to have a compile-time dispatch mechanism without the need to do a runtime "type switch" somewhere in the code. Thank you.

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  • Java inheritance and super() isn't working as expected

    - by dwwilson66
    For a homework assignment, I'm working with the following. It's an assigned class structure, I know it's not the best design by a long shot. Class | Extends | Variables -------------------------------------------------------- Person | None | firstName, lastName, streetAddress, zipCode, phone CollegeEmployee | Person | ssn, salary,deptName Faculty | CollegeEmployee | tenure(boolean) Student | person | GPA,major So in the Faculty class... public class Faculty extends CollegeEmployee { protected String booleanFlag; protected boolean tenured; public Faculty(String firstName, String lastName, String streetAddress, String zipCode, String phoneNumber,String ssn, String department,double salary) { super(firstName,lastName,streetAddress,zipCode,phoneNumber, ssn,department,salary); String booleanFlag = JOptionPane.showInputDialog (null, "Tenured (Y/N)?"); if(booleanFlag.equals("Y")) tenured = true; else tenured = false; } } It was my understanding that super() in Faculty would allow access to the variables in CollegeEmployee as well as Person. With the code above, it compiles fine when I ONLY include the Person variables. As soon as I try to use ssn, department, or salary I get the following compile errors. Faculty.java:15: error: constructor CollegeEmployee in class CollegeEmployee can not be applied to the given types: super(firstName,lastName,streetAddress,zipCode,phoneNumber,ssn,department,salary); ^ Required: String,String,String,String,String Found: String,String,String,String,String,String,String,String reason: actual and formal argument lists differ in length I'm completely confused by this error...which is the actual and formal? Person has five arguments, CollegeEmployee has 3, so my guess is that something's funky with how the parameters are being passed...but I'm not quite sure where to begin fixing it. What am I missing?

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  • Detection of negative integers using bit operations

    - by Nawaz
    One approach to check if a given integer is negative or not, could be this: (using bit operations) int num_bits = sizeof(int) * 8; //assuming 8 bits per byte! int sign_bit = given_int & (1 << (num_bits-1)); //sign_bit is either 1 or 0 if ( sign_bit ) { cout << "given integer is negative"<<endl; } else { cout << "given integer is positive"<<endl; } The problem with this solution is that number of bits per byte couldn't be 8, it could be 9,10, 11 even 16 or 40 bits per byte. Byte doesn't necessarily mean 8 bits! Anyway, this problem can be easily fixed by writing, //CHAR_BIT is defined in limits.h int num_bits = sizeof(int) * CHAR_BIT; //no assumption. It seems fine now. But is it really? Is this Standard conformant? What if the negative integer is not represented as 2's complement? What if it's representation in a binary numeration system that doesn't necessitate only negative integers to have 1 in it's most significant bit? Can we write such code that will be both portable and standard conformant? Related topics: Size of Primitive data types Why is a boolean 1 byte and not 1 bit of size?

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