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Search found 63 results on 3 pages for 'equivalence'.

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  • Equivalence Classes

    - by orcik
    I need to write a program for equivalence classes and get this outputs... (equiv '((a b) (a c) (d e) (e f) (c g) (g h))) => ((a b c g h) (d e f)) (equiv '((a b) (c d) (e f) (f g) (a e))) => ((a b e f g) (c d)) Basically, A set is a list in which the order doesn't matter, but elements don't appear more than once. The function should accept a list of pairs (elements which are related according to some equivalence relation), and return a set of equivalence classes without using iteration or assignment statements (e.g. do, set!, etc.). However, set utilities such as set-intersection, set-union and a function which eliminates duplicates in a list and built-in functions union, intersection, and remove-duplicates are allowed. Thanks a lot! By the way, It's not a homework question. A friend of mine need this piece of code to solve smilar questions.

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  • Equivalence Classes LISP

    - by orcik
    I need to write a program for equivalence classes and get this outputs... (equiv '((a b) (a c) (d e) (e f) (c g) (g h))) => ((a b c g h) (d e f)) (equiv '((a b) (c d) (e f) (f g) (a e))) => ((a b e f g) (c d)) Basically, A set is a list in which the order doesn't matter, but elements don't appear more than once. The function should accept a list of pairs (elements which are related according to some equivalence relation), and return a set of equivalence classes without using iteration or assignment statements (e.g. do, set!, etc.). However, set utilities such as set-intersection, set-union and a function which eliminates duplicates in a list and built-in functions union, intersection, and remove-duplicates are allowed. Thanks a lot!

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  • The SQL of Membership: Equivalence Classes & Cliques

    It is awkward to do 'Graph databases' in SQL to explore the sort of relationships and memberships in social networks because equivalence relations are classes (a set of sets) rather than sets. However one can explore graphs in SQL if the relationship has all three of the mathematical properties needed for an equivalence relationship. FREE eBook – "45 Database Performance Tips for Developers"Improve your database performance with 45 tips from SQL Server MVPs and industry experts. Get the eBook here.

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  • Python many-to-one mapping (creating equivalence classes)

    - by Adam Matan
    Hi, I have a project of converting one database to another. One of the original database columns defines the row's category. This coulmn should be mapepd to a new category in the new databse. For example, let's assume the original categories are:parrot, spam, cheese_shop, Cleese, Gilliam, Palin Now that's a little verbose for me, And I want to have these rows categorized as sketch, actor - That is, define all the sketches and all the actors as two equivalence classes. >>> monty={'parrot':'sketch', 'spam':'sketch', 'cheese_shop':'sketch', 'Cleese':'actor', 'Gilliam':'actor', 'Palin':'actor'} >>> monty {'Gilliam': 'actor', 'Cleese': 'actor', 'parrot': 'sketch', 'spam': 'sketch', 'Palin': 'actor', 'cheese_shop': 'sketch'} That's quite awkward- I would prefer having something like: monty={ ('parrot','spam','cheese_shop'): 'sketch', ('Cleese', 'Gilliam', 'Palin') : 'actors'} But this, of course, sets the entire tuple as a key: >>> monty['parrot'] Traceback (most recent call last): File "<pyshell#29>", line 1, in <module> monty['parrot'] KeyError: 'parrot' Any ideas how to create an elegant many-to-one dictionary in Python? Thanks, Adam

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  • Resolving equivalence relations

    - by Luca Cerone
    I am writing a function to label the connected component in an image (I know there are several libraries outside, I just wanted to play with the algorithm). To do this I label the connected regions with different labels and create an equivalence table that contain information on the labels belonging to the same connected component. As an example if my equivalence table (vector of vector) looks something like: 1: 1,3 2: 2,3 3: 1,2,3 4: 4 It means that in the image there are 2 different regions, one made of elements that are labelled 1,2,3 and an other made of elements labelled 4. What is an easy and efficient way to resolve the equivalences and end up with something that looks like: 1: 1,2,3 2: 4 that I can use to "merge" the different connected regions belonging to the same connected component? Thanks a lot for the help!

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  • C#: Oracle Data Type Equivalence with OracleDbType

    - by Partial
    Situation: I am creating an app in C# that uses Oracle.DataAccess.Client (11g) to do certain operations on a Oracle database with stored procedures. I am aware that there is a certain enum (OracleDbType) that contains the Oracle data types, but I am not sure which one to use for certain types. Questions: What is the equivalent Oracle PL/SQL data type for each enumerated type in the OracleDbType enumeration? There are three types of integer (Int16, Int32, Int64) in the OracleDbType... how to know which one to use or are they all suppose to work?

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  • How to use lists in equivalence partitioning?

    - by KhDonen
    I have read that equivalence partitioning can be used typically for intervals or lists, e.g. I assume it can be used for every set of inputs. Anyway if the requirement says that allowed colors are (RED,BLUE,BLACK, GREEN), I cannot treat them like a list, right? I mean, testing one of them would not be enough because developers most likely used some switch-case and thus it is not real "set" where one could represent also the others. So how it is meant with lists? Also what is not that clear to me, I do not think it is always possible to do the initial partioning and then design the test cases. What about checking two lines intersection: Y=MX+C. (two inputs) 1) The lines are paraller. M1=M1 but C1 must be different from C2. 2) Lines are intersecting. M1 must be different from M2. 3) Coincident. The are the same. How can I use partitioning here? THis is actually taken from a book and it says that these sets are eq.classes.

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  • Entity Framework equivalence for NHibernte SchemaExport

    - by jbandi
    Is there an equivalence in Entity Framework to NHibernate SchemaExport? Given I have a working Entity-Model, I would like to programmatically initialize a database. I would like to use this functionality in the setup of my integration tests. Creating the matching DDL for an Entity-Model would also suffice.

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  • Python's equivalence?

    - by user304014
    Is there anyway to transform the following code in Java to Python's equivalence? public class Animal{ public enum AnimalBreed{ Dog, Cat, Cow, Chicken, Elephant } private static final int Animals = AnimalBreed.Dog.ordinal(); private static final String[] myAnimal = new String[Animals]; private static Animal[] animal = new Animal[Animals]; public static final Animal DogAnimal = new Animal(AnimalBreed.Dog, "woff"); public static final Animal CatAnimal = new Animal(AnimalBreed.Cat, "meow"); private AnimalBreed breed; public static Animal myDog (String name) { return new Animal(AnimalBreed.Dog, name); } }

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  • Code equivalence between Javascript and PHP

    - by xdevel2000
    I'm trying to learn PHP and I wish to know if there are some function equivalence constructs: In JS I can do: var t = function() {}; t(); myObj.DoStuff = function() {} // here I add a method at run-time myObj.DoStuff(); myObj["DoStuff"](); var j = myObj.DoStuff; j(); and so other things with function evaluation. In Js objects are associative arrays so every properties is accessible with the subscript notation... Can I add a method at run-time to a class template so next its object instances can have it? In JS I can do that via a prototype function property.

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  • Core dump equivalence for Java

    - by m3rLinEz
    So far I have learned about generating thread dump and heap dump using jstack and and jmap respectively. However, jstack thread dump contains only texts describing the stack on each thread. And opening heap dump (.hprof file) with Java VisualVM only shows the objects allocated in the heap. What I actually want is to be able see the stack, to switch to particular stack frame, and watch local variables. This kind of post-mortem debugging can be done normally with tools like WinDbg, gdb and a core file (for a native C++ program.) I wonder if such 'core' file (which will allow me to debug in non-live environment) exists in Java?

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  • Is there an equivalence to CDOSYS AutoGenerateTextBody in .NET

    - by AnthonyWJones
    I'm porting some VBScript code which generates emails using the standard CDOSYS Message object. The Message oject has a property AutoGenerateTextBody which when true will cause it to automatically create the TextBody property value when you assign HTML to the HTMLBody property. Hence creating the typical text/plain and text/html alternatives in the message body. However .NET appears to be missing this function. The MailMessage object does have the ability to create alternative views but there doesn't appear to be a way to easily create the text body content from the HTML content. I'm not necessarily looking for an auto-magic option but I do need a solution to taking what is an HTML string and converting it to a reasonable plain text representation. Just dropping all the HTML markup doesn't cut it. Is there a tool buried somewhere in the existing .NET framework that can do this?

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  • Equivalence of boolean expressions

    - by Iulian Serbanoiu
    Hello, I have a problem that consist in comparing boolean expressions ( OR is +, AND is * ). To be more precise here is an example: I have the following expression: "A+B+C" and I want to compare it with "B+A+C". Comparing it like string is not a solution - it will tell me that the expressions don't match which is of course false. Any ideas on how to compare those expressions? Any ideas about how can I tackle this problem? I accept any kind of suggestions but (as a note) the final code in my application will be written in C++ (C accepted of course). An normal expression could contain also parenthesis: (A * B * C) + D or A+B*(C+D)+X*Y Thanks in advance, Iulian

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  • Formal Equivalence between programming languages

    - by Ketan
    Hello We have 2 languages which are (informally) semantically equivalent but syntactically different. One is xml and another is script based. How can I go about formally proving that both languages are in fact equivalent. Script approach is just a convenient way to write a same program that would be tedious to write in xml. Thanks Ketan

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  • Comparing two Objects which implement the same interface for equality / equivalence - Design help

    - by gav
    Hi All, I have an interface and two objects implementing that interface, massively simplied; public interface MyInterface { public int getId(); public int getName(); ... } public class A implements MyInterface { ... } public class B implements MyInterface { ... } We are migrating from using one implementation to the other but I need to check that the objects of type B that are generated are equivalent to those of type A. Specifically I mean that for all of the interface methods an object of Type A and Type B will return the same value (I'm just checking my code for generating this objects is correct). How would you go about this? Map<String, MyInterface> oldGeneratedObjects = getOldGeneratedObjects(); Map<String, MyInterface> newGeneratedObjects = getNewGeneratedObjects(); // TODO: Establish that for each Key the Values in the two maps return equivalent values. I'm looking for good coding practices and style here. I appreciate that I could just iterate through one key set pulling out both objects which should be equivalent and then just call all the methods and compare, I'm just thinking there may be a cleaner, more extensible way and I'm interested to learn what options there might be. Would it be appropriate / possible / advised to override equals or implement Comparable? Thanks in advance, Gavin

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  • Typedef equivalence in function arguments

    - by Warren Seine
    Hi guys, The question is kind of hard to ask without an example so here it is: #include <vector> struct O { }; struct C { template <typename T> void function1(void (C::*callback)(const O*)); template <typename T> void function2(void (C::*callback)(const typename T::value_type)); void print(const O*); }; int main() { C c; c.function1< std::vector<O*> >(&C::print); // Success. c.function2< std::vector<O*> >(&C::print); // Fail. } The error that I am given is: error: no matching function for call to ‘C::function2(void (C::*)(const O*))’. Basically, the only difference between calls is that in function2, I'm more generic since I use the typedef std::vector<O*>::value_type which should resolve to O*, hence similar to function1. I'm using G++ 4.2.1 (I know it's old), but Comeau confirms I'm wrong. Why does the compilation fail?

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  • Is there equivalences between Microsoft and Oracle/Sun technologies?

    - by Junior Mayhé
    Hello is it possible to say what are the Microsoft equivalents technologies compared to Sun? For example: Microsoft | Sun --------------------------------------------------------------- Visual Studio | Eclipse? IIS | Apache? ASP.NET | JSP, JSF ? SQL Server | Java DB ? ADO.NET Entity Data Model | ??? ASP.NET MVC | ??? Windows Presentation Foundation | Java FX? Windows Communication Foundation | ??? ASP.NET AJAX Toolkit | ??? Reporting Services/RDLC | ??? LINQ to SQL Classes | ??? Windows Forms | ???

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  • In C and C++, what methods can prevent accidental use of the assignment(=) where equivalence(==) is needed?

    - by DeveloperDon
    In C and C++, it is very easy to write the following code with a serious error. char responseChar = getchar(); int confirmExit = 'y' == tolower(responseChar); if (confirmExit = 1) { exit(0); } The error is that the if statement should have been: if (confirmExit == 1) As coded, it will exit every time, because the assignment of the confirmExit variable occurs, then confirmExit is used as the result of the expression. Are there good ways to prevent this kind of error?

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  • Which is more important in a web application code promotion hierarchy? production environment to repo equivalence or unidirectional propagation?

    - by ghbarratt
    Lets say you have a code promotion hierarchy consisting of several environments, (the polar end) two of which are development (dev) and production (prod). Lets say you also have a web application where important (but not developer controlled) files are created (and perhaps altered) in the production environment. Lets say that you (or someone above you) decided that the files which are controlled/created/altered/deleted in the production environment needed to go into the repository. Which of the following two sets of practice / approaches do you find best: Committing these non-developed file modifications made in the production environment so that the repository reflects the production environment as closely and as often as possible. Generally ignoring the non-developed production environment alterations, placing confidence in backups to restore the production environment should it be harmed, and keeping a resolution to avoid pushing developments through the promotion hierarchy in the reverse direction (avoiding pushing from prod to dev), only committing the files found in the production environment if they were absolutely necessary in other environments for development. So, 1 or 2, and why? PS - I am currently slightly biased toward maintaining production environment to repository equivalence (option 1), but I keep an open mind and would accept an answer supporting either.

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