Search Results

Search found 24879 results on 996 pages for 'prime number'.

Page 473/996 | < Previous Page | 469 470 471 472 473 474 475 476 477 478 479 480  | Next Page >

  • C++ Filling an 1D array to represent a n-dimensional object based on a straight line segment

    - by Ben
    I'm struggling to find a good way to put this question but here goes. I'm making a system that uses a 1D array implemented as double * parts_ = new double[some_variable];. I want to use this to hold co-ordinates for a particle system that can run in various dimensions. What I want to be able to do is write a generic fill algorithm for filling this in n-dimensions with a common increment in all direction to a variable size. Examples will serve best I think. Consider the case where the number of particles stored by the array is 4 In 1D this produces 4 elements in the array because each particle only has one co-ordinate. 1D: {0, 25, 50, 75}; In 2D this produces 8 elements in the array because each particle has two co-ordinates.. 2D: {0, 0, 0, 25, 25, 0, 25, 25} In 3D this produces 12 elements in the array because each particle now has three co-ordinates {0, 0, 0, 0, 0, 25, 0, 0, 50, ... } These examples are still not quite accurate, but they hopefully will suffice. The way I would do this normally for two dimensions: int i = 0; for(int x = 0; x < parts_size_ / dims_ / dims_ * 25; x += 25) { for(int y = 0; y < parts_size_ / dims_ / dims_ * 25; y += 25) { parts_[i] = x; parts_[i+1] = y; i+=2; // Indentation hates me today .< How can I implement this for n-dimensions where 25 can be any number? The straight line part is because it seems to me logical that a line is a somewhat regular shape in 1D, as is a square in 2D, and a cube in 3D. It seems to me that it would follow that there would be similar shapes in this family that could be implemented for 4D and higher dimensions via a similar fill pattern. This is the shape I wish to set my array to represent.

    Read the article

  • Forcing entry of certain character types in UITextField

    - by cannyboy
    If I have a UITextField which the user is inputing a registration number, which has the format: 11-11-1111 (that is 2 digits, a dash, 2 digits, a dash, four digits) How do I force the user to enter this kind of data only... so they can't enter anything except 0-9 in the first character, and only '-' for the third character etc.

    Read the article

  • Fast inter-process (inter-threaded) communications IPC on large multi-cpu system.

    - by IPC
    What would be the fastest portable bi-directional communication mechanism for inter-process communication where threads from one application need to communicate to multiple threads in another application on the same computer, and the communicating threads can be on different physical CPUs). I assume that it would involve a shared memory and a circular buffer and shared synchronization mechanisms. But shared mutexes are very expensive (and there are limited number of them too) to synchronize when threads are running on different physical CPUs.

    Read the article

  • How to get RSS feed item count?

    - by Adam Kane
    Hello, In C#, .NET 3.5, in a Windows Forms application... How does one get the integer count of the number of items that a given RSS url returns? Example: For my blog at: http://forgefx.blogspot.com/feeds/posts/default The expected result would be: postCount = 25 Thanks!

    Read the article

  • SQL Design Question regarding schema and if Name value pair is the best solution

    - by Aur
    I am having a small problem trying to decide on database schema for a current project. I am by no means a DBA. The application parses through a file based on user input and enters that data in the database. The number of fields that can be parsed is between 1 and 42 at the current moment. The current design of the database is entirely flat with there being 42 columns; some have repeated columns such as address1, address2, address3, etc... This says that I should normalize the data. However, data integrity is not needed at this moment and the way the data is shaped I'm looking at several joins. Not a bad thing but the data is still in a 1 to 1 relationship and I still see a lot of empty fields per row. So my concerns are that this does not allow the database or the application to be very extendable. If they want to add more fields to be parsed (which they do) than I'd need to create another table and add another foreign key to the linking table. The third option is I have a table where the fields are defined and a table for each record. So what I was thinking is to make a table that stores the value and then links to those two tables. The problem is I can picture the size of that table growing large depending on the input size. If someone gives me a file with 300,000 records than 300,000 x 40 = 12 million so I have some reservations. However I think if I get to that point than I should be happy it is being used. This option also allows for more custom displaying of information albeit a bit more work but little rework even if you add more fields. So the problem boils down to: 1. Current design is a flat file which makes extending it hard and it is not normalized. 2. Normalize the tables although no real benefits for the moment but requirements change. 3. Normalize it down into the name value pair and hope size doesn't hurt. There are a large number of inserts, updates, and selects against that table. So performance is a worry but I believe the saying is design now, performance testing later? I'm probably just missing something practical so any comments would be appreciated even if it’s a quick sanity check. Thank you for your time.

    Read the article

  • mysql get last auto increment value

    - by Mick
    Hi I have a field in mySql table called jobnumber which auto increments with each new entry. What I want to do is when a user views my form, get the value of the next 'jobnumber' . But I want to do this before any entry is made to the table. IE so when a user looks at a form it will display something like 'this is job number 6954' I have tried $rr = mysql_insert_id() but this only work after I have made an entry Can anyone help please thanks

    Read the article

  • Reset SQL variable inside SELECT statement

    - by Jason McCreary
    I am trying to number some rows on a bridge table with a single UPDATE/SELECT statement using a counter variable @row. For example: UPDATE teamrank JOIN (SELECT @row := @row + 1 AS position, name FROM members) USING(teamID, memberID) SET rank = position Is something like this possible or do I need to create a cursor? If it helps, I am using MySQL 5.

    Read the article

  • Reading DWORD from binary file

    - by Archcegeloge
    Why these lines of code doesn't work when i try to read a DWORD num = 1880762702 using fread(&num, "file path", 1, FILE*); I get the result = 10574 if I change the num to any other number say 2880762702 only then it works.

    Read the article

  • New table for every user?

    - by SonOfOmer
    Hi everyone, I want to crate new table for each new user on the web site and I assume that there will be many users, I am sure that search performance will be good, but what is with maintenance?? It is MySQL which has no limit in number of tables. Thanks a lot.

    Read the article

  • Image classification: recognizing various features of many buildings from images

    - by el chief
    so, let's say i have the long/lat or address of many buildings can get satellite images, "street view", and perhaps 3d/perspective views of buildings. want to find: height, number of floors, floor area (max building footprint) of the building. about 200k buildings. Is there a library for recognizing buildings from satellite shots or pictures? Kind of like face detection I suppose. Any other suggestions? Thanks!

    Read the article

  • Help with this JET Sql Query [SOLVED]

    - by yae
    Hi: I need help to do this query select. for example I have these fields: idInvoice date amount Depending of the date I need multiply the field "amount" for x number or other one. For example, if the date is less 01/01/2010 to multiply for 20 . But if it is major or equal to multiply for 35 Select idInvoice, date, amount, amount * varNumber from invoices

    Read the article

  • Have an example using the CaliberRM API with C or C++ ?

    - by TridenT
    I'm trying to build a simple tool to gather statistics from a CaliberRM server. I've got the API description with examples for VB and Java, but nothing for C or C++. Does anyone have a simple example to start with ? A kind of : Connect to a database (caliberRM server) get number of requirements ... that's all.

    Read the article

  • have an array of struct in wsdl + php without using NSoap

    - by Shadi
    Hi, I want to have an array of struct (an array of books with their specifications like publication, ISBN number, ...). in wsdl and php. I have searched a little and I have found files that uses Nusoap, However, I dont want to use NuSoap. Is there any solution? I would appreciate if you help me in writing the related wsdl, client and server (php) files. Thank you so much. Best, shadi.

    Read the article

  • I need to modify a program to use arrays and a method call. Should I modify the running file, the data collection file, or both?

    - by g3n3rallyl0st
    I have to have multiple classes for this program. The problem is, I don't fully understand arrays and how they work, so I'm a little lost. I will post my program I have written thus far so you can see what I'm working with, but I don't expect anyone to DO my assignment for me. I just need to know where to start and I'll try to go from there. I think I need to use a double array since I will be working with decimals since it deals with money, and my method call needs to calculate total price for all items entered by the user. Please help: RUNNING FILE package inventory2; import java.util.Scanner; public class RunApp { public static void main(String[] args) { Scanner input = new Scanner( System.in ); DataCollection theProduct = new DataCollection(); String Name = ""; double pNumber = 0.0; double Units = 0.0; double Price = 0.0; while(true) { System.out.print("Enter Product Name: "); Name = input.next(); theProduct.setName(Name); if (Name.equalsIgnoreCase("stop")) { return; } System.out.print("Enter Product Number: "); pNumber = input.nextDouble(); theProduct.setpNumber(pNumber); System.out.print("Enter How Many Units in Stock: "); Units = input.nextDouble(); theProduct.setUnits(Units); System.out.print("Enter Price Per Unit: "); Price = input.nextDouble(); theProduct.setPrice(Price); System.out.print("\n Product Name: " + theProduct.getName()); System.out.print("\n Product Number: " + theProduct.getpNumber()); System.out.print("\n Amount of Units in Stock: " + theProduct.getUnits()); System.out.print("\n Price per Unit: " + theProduct.getPrice() + "\n\n"); System.out.printf("\n Total cost for %s in stock: $%.2f\n\n\n", theProduct.getName(), theProduct.calculatePrice()); } } } DATA COLLECTION FILE package inventory2; public class DataCollection { String productName; double productNumber, unitsInStock, unitPrice, totalPrice; public DataCollection() { productName = ""; productNumber = 0.0; unitsInStock = 0.0; unitPrice = 0.0; } //setter methods public void setName(String name) { productName = name; } public void setpNumber(double pNumber) { productNumber = pNumber; } public void setUnits(double units) { unitsInStock = units; } public void setPrice(double price) { unitPrice = price; } //getter methods public String getName() { return productName; } public double getpNumber() { return productNumber; } public double getUnits() { return unitsInStock; } public double getPrice() { return unitPrice; } public double calculatePrice() { return (unitsInStock * unitPrice); } }

    Read the article

  • show line in exception.message

    - by Crash893
    How would one display what line number caused the error and is this even possible with the way that .net compiles its exes? If not is there an automated way for exception.message to display the sub that crapped out? try { int x = textbox1.text; } catch(exception ex) { messagebox.show(ex.message); }

    Read the article

  • textbox accept only digits

    - by hiba salem
    Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress Dim allowedChars As String = "0123456789$," If allowedChars.IndexOf(e.KeyChar) = -1 Then ' Invalid Character e.Handled = True End If End Sub this code accept only digits and its working like a charm but if i typed a wrong number its not allowing me to use the delete or the backspace on the keyboard how to solve this problem ?

    Read the article

  • Converting a const char* into a double

    - by Koning Baard
    I am trying to convert a const char* to a double precision floating point number: int main(const int argc, const char *argv[]) { int i; double numbers[argc - 1]; for(i = 1; i < argc, i += 1) { /* -- Convert each argv into a double and put it in `number` */ } /* ... */ return 0; } Can anyone help me? Thanks

    Read the article

  • Benchmark of Java Try/Catch Block

    - by hectorg87
    I know that going into a catch block has some significance cost when executing a program, however, I was wondering if entering a try{} block also had any impact so I started looking for an answer in google with many opinions, but no benchmarking at all. Some answers I found were: Java try/catch performance, is it recommended to keep what is inside the try clause to a minimum? Try Catch Performance Java Java try catch blocks However they didn't answer my question with facts, so I decided to try it for myself. Here's what I did. I have a csv file with this format: host;ip;number;date;status;email;uid;name;lastname;promo_code; where everything after status is optional and will not even have the corresponding ; , so when parsing a validation has to be done to see if the value is there, here's where the try/catch issue came to my mind. The current code that in inherited in my company does this: StringTokenizer st=new StringTokenizer(line,";"); String host = st.nextToken(); String ip = st.nextToken(); String number = st.nextToken(); String date = st.nextToken(); String status = st.nextToken(); String email = ""; try{ email = st.nextToken(); }catch(NoSuchElementException e){ email = ""; } and it repeats what it's done for email with uid, name, lastname and promo_code. and I changed everything to: if(st.hasMoreTokens()){ email = st.nextToken(); } and in fact it performs faster. When parsing a file that doesn't have the optional columns. Here are the average times: --- Trying:122 milliseconds --- Checking:33 milliseconds however, here's what confused me and the reason I'm asking: When running the example with values for the optional columns in all 8000 lines of the CSV, the if() version still performs better than the try/catch version, so my question is Does really the try block does not have any performance impact on my code? The average times for this example are: --- Trying:105 milliseconds --- Checking:43 milliseconds Can somebody explain what's going on here? Thanks a lot

    Read the article

  • Hidden features of mod_rewrite

    - by Owen
    There seem to be a decent number of mod_rewrite threads floating around lately with a bit of confusion over how certain aspects of it work. As a result I've compiled a few notes on common functionality, and perhaps a few annoying nuances. What other features / common issues have you run across using mod_rewrite?

    Read the article

  • How to Calculate longest streak in SQL?

    - by VJ
    I have EMPLOYEE-ID,DATE,IsPresent I want to calculate longest streak for a employee presence.The Present bit will be false for days he didnt come..So I want to calculate the longest number of days he came to office for consecutive dates..I have the Date column field is unique...So I tried this way - Select Id,Count(*) from Employee where IsPresent=1 But the above doesnt work...Can anyone guide me towards how I can calculate streak for this?....I am sure people have come across this...I tried searching online but...didnt understand it well...please help me out..

    Read the article

  • sorting array after array_count_values

    - by umermalik
    hi to all! I have an array of products $products = array_count_values($products); now I have an array where $key is product number and $value is how many times I have such a product in the array. I want to sort this new array that product with the least "duplicates" are on the first place, but what ever I use (rsort, krsort,..) i loose product numbers (key). any suggestions? thanks.

    Read the article

< Previous Page | 469 470 471 472 473 474 475 476 477 478 479 480  | Next Page >