Search Results

Search found 17940 results on 718 pages for 'algorithm design'.

Page 125/718 | < Previous Page | 121 122 123 124 125 126 127 128 129 130 131 132  | Next Page >

• Design review - do you think I'm doing this the right way? First commercial project for me!

  - by Sergio Tapia

  I'm tasked with designing an application that will allow a person to scan a legal document, save that associated with a Name and save it to a database. Now, inside of the Organization, there are many departments, and each department can have many sub departments. Problem lies in that some larger organizations will have many departments and smallers ones will only have 1 or two. I've though about creating a Department table and a Supdepartment table to create associations, etc. That way it's extensible and users can dynamically create departments to fit my program to their organizational scheme. Am I approaching this the right way? As I said, this is my first commercial application so I want to do it right and set a name for myself for delivering things on time and good code for other to expand upon.

  Read the article

• What resources will help me understand the fundamentals of Relational Database Design.

  - by Rachel

  This are few of the fundamental database questions which has always given me trouble. I have tried using google and wiki but I somehow I miss out on understanding the functionality rather than terminology. If possible would really appreciate if someone can share more insights on this questions using some visual representative examples. What is a key? A candidate key? A primary key? An alternate key? A foreign key? What is an index and how does it help your database? What are the data types available and when to use which ones?

  Read the article

• Given a number of rectangles that can be rotated, find an enclosing rectangle of minimum area

  - by efficiencyIsBliss

  So, I'm trying to implement an algorithm that takes in a number of rectangles as input and tries to pack them into a rectangle of minimum area. The rectangles can all be rotated by 90 degrees. I realize that this is similar to the bin packing problem, but I am unable to find a good algorithm that accounts for the rotation. I found a paper that discusses this at length here and while I understand the article itself, I was hoping to find something simpler. Any suggestions? -Edit- I think I misstated the problem earlier. We are given a number of rectangles, such that each can be rotated by 90 degrees. We need to find a rectangle that fits all the given rectangles such that no two rectangles overlap, while minimizing the area of the enclosing rectangle. The problem I face here is that we are asked to find the minimum, as opposed to being given an enclosing rectangle and checking if the given rectangles fit or something of that sort.

  Read the article

• MVC design in Cocoa - are all 3 always necessary? Also: naming conventions, where to put Controller

  - by Nektarios

  I'm new to MVC although I've read a lot of papers and information on the web. I know it's somewhat ambiguous and there are many different interpretations of MVC patterns.. but the differences seem somewhat minimal My main question is - are M, V, and C always going to be necessary to be doing this right? I haven't seen anyone address this in anything I've read. Examples (I'm working in Cocoa/Obj-c although that shouldn't much matter).. 1) If I have a simple image on my GUI, or a text entry field that is just for a user's convenience and isn't saved or modified, these both would be V (view) but there's no M (no data and no domain processing going on), and no C to bridge them. So I just have some aspects that are "V" - seems fine 2) I have 2 different and visible windows that each have a button on them labeled as "ACTIVATE FOO" - when a user clicks the button on either, both buttons press in and change to say "DEACTIVATE FOO" and a third window appears with label "FOO". Clicking the button again will change the button on both windows to "ACTIVATE FOO" and will remove the third "FOO" window. In this case, my V consists of the buttons on both windows, and I guess also the third window (maybe all 3 windows). I definitely have a C, my Controller object will know about these buttons and windows and will get their clicks and hold generic states regarding windows and buttons. However, whether I have 1 button or 10 button, my window is called "FOO" or my window is called "BAR", this doesn't matter. There's no domain knowledge or data here - just control of views. So in this example, I really have "V" and "C" but no "M" - is that ok? 3) Final example, which I am running in to the most. I have a text entry field as my View. When I enter text in this, say a number representing gravity, I keep it in a Model that may do things like compute physics of a ball while taking in to account my gravity parameter. Here I have a V and an M, but I don't understand why I would need to add a C - a controller would just accept the signals from the View and pass it along to the Model, and vice versa. Being as the C is just a pure passthrough, it's really "junk" code and isn't making things any more reusable in my opinion. In most situations, when something changes I will need to change the C and M both in nearly identical ways. I realize it's probably an MVC beginner's mistake to think most situations call for only V and M.. leads me in to next subject 4) In Cocoa / Xcode / IB, I guess my Controllers should always be an instantiated object in IB? That is, I lay all of my "V" components in IB, and for each collection of View objects (things that are related) I should have an instantiated Controller? And then perhaps my Models should NOT be found in IB, and instead only found as classes in Xcode that tie in with Controller code found there. Is this accurate? This could explain why you'd have a Controller that is not really adding value - because you are keeping consistent.. 5) What about naming these things - for my above example about FOO / BAR maybe something that ends in Controller would be the C, like FancyWindowOpeningController, etc? And for models - should I suffix them with like GravityBallPhysicsModel etc, or should I just name those whatever I like? I haven't seen enough code to know what's out there in the wild and I want to get on the right track early on Thank you in advance for setting me straight or letting me know I'm on the right track. I feel like I'm starting to get it and most of what I say here makes sense, but validation of my guessing would help me feel confident..

  Read the article

• A simple algorithm for polygon intersection

  - by Elazar Leibovich

  I'm looking for a very simple algorithm for computing the polygon intersection/clipping. That is, given polygons P, Q, I wish to find polygon T which is contained in P and in Q, and I wish T to be maximal among all possible polygons. I don't mind the run time (I have a few very small polygons), I can also afford getting an approximation of the polygons' intersection (that is, a polygon with less points, but which is still contained in the polygons' intersection). But it is really important for me that the algorithm will be simple (cheaper testing) and preferably short (less code). edit: please note, I wish to obtain a polygon which represent the intersection. I don't need only a boolean answer to the question of whether the two polygons intersect.

  Read the article

• Fastest way of converting a quad to a triangle strip?

  - by Tina Brooks

  What is the fastest way of converting a quadrilateral (made up of foyr x,y points) to a triangle strip? I'm well aware of the general triangulation algorithms that exist, but I need a short, well optimized algorithm that deals with quadrilaterals only. My current algorithm does this, which works for most quads but still gets the points mixed up for some: #define fp(f) bounds.p##f /* Sort four points in ascending order by their Y values */ point_sort4_y(&fp(1), &fp(2), &fp(3), &fp(4)); /* Bottom two */ if (fminf(-fp(1).x, -fp(2).x) == -fp(2).x) { out_quad.p1 = fp(2); out_quad.p2 = fp(1); } else { out_quad.p1 = fp(1); out_quad.p2 = fp(2); } /* Top two */ if (fminf(-fp(3).x, -fp(4).x) == -fp(3).x) { out_quad.p3 = fp(3); out_quad.p4 = fp(4); } else { out_quad.p3 = fp(4); out_quad.p4 = fp(3); }

  Read the article

• PHP OOP Design Patterns: Should I Create two seperate classes for registration and form validation?

  - by Joshua Poshua

  So here's my problem: I have two types of registration, registration A and registration B, each will have some of the same fields and some different fields. I was going to create abstract class registration and both A and B would have their own classes that extend from registration. My question is, should I create a seperate Validation class with seperate A and B validation classes that extend? or is there a better pattern to use for something like this? Thanks

  Read the article

• UX Design Question: Should a multi step wizard save the form contents when the user clicks 'go back'

  - by Ashwin Prabhu

  I am developing a web application that collects data over multiple steps through a wizard. Steps are generally not interdependent, in that data input at each step has little or no effect on the consequent steps. However each step may have a set of validations which determine whether the user can progress to the next step by clicking 'continue' What should be the behavior when the user clicks previous? a Quickly move to the previous page, thus losing all the unsaved data in the form. Prompting the user with a warning is an option, but it can become irritating quite soon. b Move to the previous page saving all the data in the current step - without triggering validations, so that when the user comes back she sees the form in the same state that she left it in. c any other behaviour All opinions are welcome :)

  Read the article

• c++ Design pattern for CoW, inherited classes, and variable shared data?

  - by krunk

  I've designed a copy-on-write base class. The class holds the default set of data needed by all children in a shared data model/CoW model. The derived classes also have data that only pertains to them, but should be CoW between other instances of that derived class. I'm looking for a clean way to implement this. If I had a base class FooInterface with shared data FooDataPrivate and a derived object FooDerived. I could create a FooDerivedDataPrivate. The underlying data structure would not effect the exposed getters/setters API, so it's not about how a user interfaces with the objects. I'm just wondering if this is a typical MO for such cases or if there's a better/cleaner way? What peeks my interest, is I see the potential of inheritance between the the private data classes. E.g. FooDerivedDataPrivate : public FooDataPrivate, but I'm not seeing a way to take advantage of that polymorphism in my derived classes. class FooDataPrivate { public: Ref ref; // atomic reference counting object int a; int b; int c; }; class FooInterface { public: // constructors and such // .... // methods are implemented to be copy on write. void setA(int val); void setB(int val); void setC(int val); // copy constructors, destructors, etc. all CoW friendly private: FooDataPrivate *data; }; class FooDerived : public FooInterface { public: FooDerived() : FooInterface() {} private: // need more shared data for FooDerived // this is the ???, how is this best done cleanly? };

  Read the article

• Support-function in the GJK-algorithm.

  - by Marcus Johansson

  I am trying to implement the GJK-algorithm but I got stuck instantly. The problem is to implement the Support-function that isn't O(n^2). As it is now I'm computing the complete Minkowski difference, and then there is really no point in doing the GJK-algorithm. (or is it?) What I mean by Support-function is the function that returns the point in the Minkowski difference that is furthest away in a specified direction. I assume this shouldn't be O(n^2) as it is in my current implementation.

  Read the article

• Which design pattern should be used to create an emulator?

  - by Facon

  I have programmed an emulator, but I have some doubts about how to organizate it properly, because, I see that it has some problems about classes connection (CPU <- Machine Board). For example: I/O ports, interruptions, communication between two or more CPU, etc. I need for the emulator to has the best performance and good understanding of the code. PD: Sorry for my bad English. EDITED - Asking for multiple patterns.

  Read the article

• Database table design vs. ease of use.

  - by Gastoni

  I have a table with 3 fields: color, fruit, date. I can pick 1 fruit and 1 color, but I can do this only once each day. examples: red, apple, monday red, mango, monday blue, apple, monday blue, mango, monday red, apple, tuesday The two ways in which I could build the table are: 1.- To have color, fruit and date be a composite primary key (PK). This makes it easy to insert data into the table because all the validation needed is done by the database. PK color PK fruit PK date 2.- Have and id column set as PK and then all the other fields. Many say thats the way it should be, because composite PKs are evil. For example, CakePHP does no support them. PK id color fruit date Both have advantages. Which would be the 'better' approach?

  Read the article

• Should I design the application or model (database) first?

  - by YonahW

  I am getting ready to start building a new web project in my spare time to bring to fruition an idea that has been bouncing around my head for a while. I have never gotten down whether I am better off first building the model and then the consuming application or the other way around. What are the best practices? What would you build first and why? I imagine that in general the application should generally drive the model, however the application like many websites really doesn't do much without the model. For some reason I find it easier at times to think in terms of the model since the application is really just actions on the model. Is this a poor way of thinking about things? What advantages/disadvantages does each option have?

  Read the article

• Is Perl code mainly written in object-oriented-design?

  - by sid_com

  Since there is for almost everything a module and it is repeatedly said that we should not reinvent the wheel and since I do not write modules for cpan I have no need to use OO. But my question is, is professional Perlcode mainly written in OO-style?

  Read the article

• Measuring the performance of classification algorithm

  - by Silver Dragon

  I've got a classification problem in my hand, which I'd like to address with a machine learning algorithm ( Bayes, or Markovian probably, the question is independent on the classifier to be used). Given a number of training instances, I'm looking for a way to measure the performance of an implemented classificator, with taking data overfitting problem into account. That is: given N[1..100] training samples, if I run the training algorithm on every one of the samples, and use this very same samples to measure fitness, it might stuck into a data overfitting problem -the classifier will know the exact answers for the training instances, without having much predictive power, rendering the fitness results useless. An obvious solution would be seperating the hand-tagged samples into training, and test samples; and I'd like to learn about methods selecting the statistically significant samples for training. White papers, book pointers, and PDFs much appreciated!

  Read the article

• Why increase pointer by two while finding loop in linked list, why not 3,4,5?

  - by GG

  I had a look at question already which talk about algorithm to find loop in a linked list. I have read Floyd's cycle-finding algorithm solution, mentioned at lot of places that we have to take two pointers. One pointer( slower/tortoise ) is increased by one and other pointer( faster/hare ) is increased by 2. When they are equal we find the loop and if faster pointer reaches null there is no loop in the linked list. Now my question is why we increase faster pointer by 2. Why not something else? Increasing by 2 is necessary or we can increase it by X to get the result. Is it necessary that we will find a loop if we increment faster pointer by 2 or there can be the case where we need to increment by 3 or 5 or x.

  Read the article

• What is the best Design/Way to keep user connected ?

  - by Fasih Hansmukh

  Am working on a POC for self learning in which I want to keep my user connected in LIVE pattern. For example, A game in which 4 user can play at a time , here I need to keep this user connected to my game . M not good at Socket type of programming and love to do that in Services way.What i wana know is 'What is the best way of doing this'. According to my initial Brain Storming, I have decided that I will use SilverLight(In Browser Or Out of Browser) as Front end [I have no issue in that]. I m more concern in back end. Either I make an handler or make a WCF service or use full duplex service and use pooling mechanism for that. As a random thought I come up with a Timer type logic that will fire every after 10 seconds at clients end and get status like Is it now Its turn to roll a dice Home many user left (in case if some of them left) What are connected user status in game like there score/points ect and update game view according to this at his end Kindly place your best answers here that will help me to learn this. Regards and thanks in Advance EDIT: Starting Bounty as i need more feedback. FH

  Read the article

• True or False: Good design calls for every table to have a primary key, if nothing else, a running i

  - by Velika

  Consider a grocery store scenario (I'm making this up) where you have FACT records that represent a sale transaction, where the columns of the Fact table include SaleItemFact Table ------------------ CustomerID ProductID Price DistributorID DateOfSale Etc Etc Etc Even if there are duplicates in the table when you consider ALL the keys, I would contend that a surrogate running numeric key (i.e. identity column) should be made up, e.g., TransactionNumber of type Integer. I can see someone arguing that a Fact table might not have a unique key (though I'd invent one and waste the 4 bytes, but how about a dimension table?

  Read the article

• How to design a command line program reusable for a future development of a GUI?

  - by systempuntoout

  What are some best practices to keep in mind when developing a script program that could be integrated with a GUI, probably by somebody else, in the future? Possible scenario: i develop a fancy python CLI program that scrapes every unicorn images from the web i decide to publish it on github a unicorn fan programmer decides to take the sources and build a GUI on them. he\she gives up because my code is not reusable How do i avoid step four and let unicorn fan programmer build his\her GUI without hassle?

  Read the article

• Pure functional bottom up tree algorithm

  - by Axel Gneiting

  Say I wanted to write an algorithm working on an immutable tree data structure that has a list of leaves as its input. It needs to return a new tree with changes made to the old tree going upwards from those leaves. My problem is that there seems to be no way to do this purely functional without reconstructing the entire tree checking at leaves if they are in the list, because you always need to return a complete new tree as the result of an operation and you can't mutate the existing tree. Is this a basic problem in functional programming that only can be avoided by using a better suited algorithm or am I missing something?

  Read the article

• Quality Design for Asynchronous WCF Services Calls in a Middle-Tier and Returning Data to UI Tier

  - by Perplexed

  I have a WPF application with a group of asynchronous WCF service calls all mashed into the code behind, complete with event handlers and everything, that I have to refactor to productionize and maintain. I want to separate concerns here for maintainability and all the other good reasons to do this, but I'm not sure exactly how to achieve this. Anybody have any good ideas on how to do this, or at least some links to put me in the right direction? My thinking: Create an "infrastructure" layer and reference the services there. Move the asynchronous event handlers into this layer. When an update is called, I will bubble up my own event with my own derivation of the EventArgs class that contains the data the UI will need. I'll have a fairly coupled hooking of the UI to the infrastructure layer as it will consume events I fire off upon completion of an asynchronous data call.

  Read the article

• What design pattern should be used to create an emulator?

  - by Facon

  I have programmed an emulator, but I have some doubts about how to organizate it properly, because, I see that it has some problems about classes connection (CPU <- Machine Board). For example: I/O ports, interruptions, communication between two or more CPU, etc. I need for the emulator to has the best performance and good understanding of the code. PD: Sorry for my bad English.

  Read the article

• Icons: How does a developer with no design skill make his/her application icons look pretty?

  - by Martin

  I probably spend far too much time trying to make my visual interfaces look good, and while I'm pretty adept at finding the right match between usability and style one area I am hopeless at is making nice looking icons. How do you people overcome this (I'm sure common) problem? I'm thinking of things like images on buttons and perhaps most important of all, the actual application icon. Do you rely on third party designers, in or out of house? Or do you know of some hidden website that offers lots of icons for us to use? I've tried Google but I seem to find either expensive packages that are very specific, millions of Star Trek icons or icons that look abysmal at 16x16 which is my preferred size on in-application buttons. Any help/advice appreciated.

  Read the article

• C optimization breaks algorithm

  - by Halpo

  I am programming an algorithm that contains 4 nested for loops. The problem is at at each level a pointer is updated. The innermost loop only uses 1 of the pointers. The algorithm does a complicated count. When I include a debugging statement that logs the combination of the indexes and the results of the count I get the correct answer. When the debugging statement is omitted, the count is incorrect. The program is compiled with the -O3 option on gcc. Why would this happen?

  Read the article

• optimized grid for rectangular items

  - by peterchen

  I have N rectangular items with an aspect ratio Aitem (X:Y). I have a rectangular display area with an aspect ratio Aview The items should be arranged in a table-like layout (i.e. r rows, c columns). what is the ideal grid rows x columns, so that individual items are largest? (rows * colums = N, of course - i.e. there may be "unused" grid places). A simple algorithm could iterate over rows = 1..N, calculate the required number of columns, and keep the row/column pair with the largest items. I wonder if there's a non-iterative algorithm, though (e.g. for Aitem = Aview = 1, rows / cols can be approximated by sqrt(N)).

  Read the article

< Previous Page | 121 122 123 124 125 126 127 128 129 130 131 132  | Next Page >