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• WPF input datagrid?

  - by SAD

  I would like to create an input DataGrid - an empty set of rows with the column headers that can be filled with data by a user and then saved to a database. The DataGrid will not be therefore used to display data but acts like an input field. The behaviour would be similar to the one of Excell. The problem is that if the DataGrid has no data provided for it, it is not visible in the application and the user cannot enter anything. Is the DataGrid a good choice? How can this sort of functionality be implemented with a different control? I would prefer to use the DataGrid tough. Thanks a lot for any help on this.

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• Solving the problem of finding parts which work well with each other

  - by dotnetdev

  Hi, I have a database of items. They are for cars and similar parts (eg cam/pistons) work better than others in different combinations (eg one product will work well with another, while another combination of 2 parts may not). There are so many possible permutations, what solutions apply to this problem? So far, I feel that these are possible approaches (Where I have question marks, something tells me these are solutions but I am not 100% confident they are). Neural networks (?) Collection-based approach (selection of parts in a collection for cam, and likewise for pistons in another collection, all work well with each other) Business rules engine (?) What are good ways to tackle this sort of problem? Thanks

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• c# error when using the Database.cs files

  - by Kumu

  Inconsistent accessibility: parameter type 'FoolballLeague.FootballLeagueDatabase' is less accessible than method 'FoolballLeague.MainMenu.MainMenu(FoolballLeague.FootballLeagueDatabase)' C:\Users\achini\Desktop\FootballLeague\FootballLeague\MainMenu.cs I have got this error when I insert this part to the code //public MainMenu(FootballLeagueDatabase footballLeagueDatabaseIn) //{ //InitializeComponent(); //footballLeagueDatabase = footballLeagueDatabaseIn; //} The whole code of the first part is as following, But I dont know what do I need to do to sort out this error. public partial class MainMenu : Form { FootballLeagueDatabase footballLeagueDatabase; Game game; Login login; public MainMenu() { InitializeComponent(); changePanel(1); } //public MainMenu(FootballLeagueDatabase footballLeagueDatabaseIn) //{ //InitializeComponent(); //footballLeagueDatabase = footballLeagueDatabaseIn; //} If you have any idea please let me know, I need this part to the system.

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• C - fork() and sharing memory

  - by Ben

  I need my parent and child process to both be able to read and write the same variable (of type int) so it is "global" between the two processes. I'm assuming this would use some sort of cross-process communication and have one variable on one process being updated. I did a quick google and IPC and various techniques come up but I don't know which is the most suitable for my situation. So what technique is best and could you provide a link to a noobs tutorial for it. Thanks.

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• Will an optimizing compiler remove calls to a method whose result will be multiplied by zero?

  - by Tim R.

  Suppose you have a computationally expensive method, Compute(p), which returns some float, and another method, Falloff(p), which returns another float from zero to one. If you compute Falloff(p) * Compute(p), will Compute(p) still run when Falloff(p) returns zero? Or would you need to write a special case to prevent Compute(p) from running unnecessarily? Theoretically, an optimizing compiler could determine that omitting Compute when Falloff returns zero would have no effect on the program. However, this is kind of hard to test, since if you have Compute output some debug data to determine whether it is running, the compiler would know not to omit it because of that debug info, resulting in sort of a Schrodinger's cat situation. I know the safe solution to this problem is just to add the special case, but I'm just curious.

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• Profiling help required

  - by Mick

  I have a profiling issue - imagine I have the following code... void main() { well_written_function(); badly_written_function(); } void well_written_function() { for (a small number) { highly_optimised_subroutine(); } } void badly_written_function() { for (a wastefully and unnecessarily large number) { highly_optimised_subroutine(); } } void highly_optimised_subroutine() { // lots of code } If I run this under vtune (or other profilers) it is very hard to spot that anything is wrong. All the hotspots will appear in the section marked "// lots of code" which is already optimised. The badly_written_function() will not be highlighted in any way even though it is the cause of all the trouble. Is there some feature of vtune that will help me find the problem? Is there some sort of mode whereby I can find the time taken by badly_written_function() and all of its sub-functions?

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• After grouping by, can I refer to the elements of the original IEnumerable in a LINQ query?

  - by michielvoo

  Example: from OriginalObject in ListOfOriginalObjects group new CustomObject { X = OriginalObject.A, Y = OriginalObject.B } by OriginalObject.Z into grouping select new GroupOfCustomObjects { Z = grouping.Key, C = OriginalObject.C, group = grouping } In the select part of the query, I'd like to add a property (OriginalObject.C) to the type GroupOfCustomObjects. But it seems that OriginalObject is out of scope in that part of the query. I can sort of understand why, since I am not grouping on that property and I am also not making that property part of CustomObject that I'm grouping. One workaround is to add a property C to CustomObject and the in the GroupOfCustomObjects read the value of the first CustomObject in the grouping. My issue with that is that I'm adding a property to an object that doesn't need it (CustomObject), just to be able to add it to the GroupOfCustomObjects. I hope I have explained this properly! Is there a way to refer to the OriginalObject that the query starts with? Thanks!

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• Avoiding try/catch hell in my web pages

  - by Shaun_web

  I am writing an ASP.NET website, which is a new framework for me. I find that I have a try/catch block in literally every method of my codebehind. All these try/catch blocks do is catch the exception and then pop-up an error message to the user. Isn't there some sort of global error handler in ASP.NET? It's worth noting that my error handling is within control (ASCX) pages, and I would like a way to simply get each ASCX to handle its own errors without forcing all error handling just to a single master page or a redirect...

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• Design patter for extending Android's activities?

  - by Carl

  While programming on Android, I end up writing a parent activity which is extended by several others. A bit like ListActivity. My parent activity extends Activity. if I intend to use a Map or a List, I can't use my parent activity as superclass - the child activity can only extend one activity obviously. As such I end up writing my parent activities with the same logic for Activity, ListActivity, MapActivity and so forth. What am I looking for is some sort of trait functionality/design pattern which would help in this case. Any suggestions?

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• What Should be the Structure of a C++ Project?

  - by Ell

  I have recently started learning C++ and coming from a Ruby environment I have found it very hard to structure a project in a way that it still compiles correctly, I have been using Code::Blocks which is brilliant but a downside is that when I add a new header file or c++ source file, it will generate some code and even though it is only a mere 3 or 4 lines, I do not know what these lines do. First of all I would like to ask this question: What do these lines do? #ifndef TEXTGAME_H_INCLUDED #define TEXTGAME_H_INCLUDED #endif // TEXTGAME_H_INCLUDED My second question is, do I need to #include both the .h file and the .cpp file, and in which order. My third question is where can I find the GNU GCC Compiler that, I beleive, was packaged with Code::Blocks and how do I use it without Code::Blocks? I would rather develop in a notepad++ sort of way because that is what I'm used to in Ruby but since C++ is compiled, you may think differently (please give advice and views on that as well) Thanks in advance, ell.

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• How do I order by foreign attribute for belongs_to reference where there are 2 keys to foreign table

  - by Will

  I have a Model which has a belongs_to association with another Model as follows class Article belongs_to :author, :class_name => "User" end If I wanted to find all articles for a particular genre ordered by author I would do something like the following articles = Article.all(:includes => [:author], :order => "users.name") However if Article happens to have two references to User how can I sort on :author? class Article belongs_to :editor, :class_name => "User" belongs_to :author, :class_name => "User" end I have tried articles = Article.all(:includes => [:author], :order => "users.name") #=> incorrect results articles = Article.all(:includes => [:author], :order => "authors.name") #=> Exception Thrown

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• How should I deal with sqlite errors?

  - by Dustin

  I have a long running application written in a mix of C and C++ that stores data in sqlite. While I am confident that committed data will remain available (barring mechanical failure) and uncommitted data will not be, it's not clear to me what I can do with this sort of middle state. I do a large number of inserts in a transaction and then commit it. When an error occurs on a given statement, I can schedule it to be attempted at some point in the future. It sounds like some errors might implicitly rollback my transaction (which would be undesirable if true). A larger problem is what happens when my commit itself fails. Currently, I'm just going to continue to retry it until it works. I would expect that whatever would cause my commit to fail may very well also cause a rollback to fail. What is the recommended mechanism for error handling in such a situation?

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• Password protected web content-- basic question

  - by nickpish

  I'm looking to create a password-protected section of my website that requires user login, and I'm wondering what approach would provide the simplest solution. For the most part, the site will be very simple and static-- i.e. no real requirement for a database/backend-- with the protected content contained in a single directory, which I've already configured on my server via htaccess. I guess I'm wondering ultimately if it's possible to use a script of some sort that will enable access to this protected directory via a form and thereby bypass the need for configuring a mySQL/PHP solution? Furthermore, this protected content is not exactly hyper-sensitive, but private nonetheless. Thanks much for any direction here.

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• PHP: include inside include

  - by Karem

  In dbc.php I have where the connection to the mysql db gets made, and all my functions is there. dbc.php is included on all my files. Now all functions are in dbc.php and i would like to sort out alittle. I was thinking about putting all form_*() functions to form_api.php, and then include it in dbc.php. But will this work? Can i just include inside a file i included? Or should i use require/include_once ? help me out thank you

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• Retrieving Large Lists of Objects Using Java EE

  - by hallidave

  Is there a generally-accepted way to return a large list of objects using Java EE? For example, if you had a database ResultSet that had millions of objects how would you return those objects to a (remote) client application? Another example -- that is closer to what I'm actually doing -- would be to aggregate data from hundreds of sources, normalize it, and incrementally transfer it to a client system as a single "list". Since all the data cannot fit in memory, I was thinking that a combination of a stateful SessionBean and some sort of custom Iterator that called back to the server would do the trick. How have you successfully solved this problem in the past?

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• How to peform an external request in Kohana 3?

  - by alex

  I've always used cURL for this sort of stuff, but this article got me thinking I could request another page easily using the Request object in Kohana 3. $url = 'http://www.example.com'; $update = Request::factory($url); $update->method = 'POST'; $update->post = array( 'key' => 'value' ); $update->execute(); echo $update->response; However I get the error Accessing static property Request::$method as non static From this I can assume it means that the method method is static, but that doesn't help me much. I also copied and pasted the example from that article and it threw the same error. Basically, I'm trying to POST to a new page on an external server, and do it the Kohana way. So, am I doing this correctly, or should I just use cURL (or file_get_contents() with context)?

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• MySQL - Counting rows in preparation for greatest-n-per-group not working?

  - by John M

  Referring to SO and other sites have given me examples of how to use MySQL to create a 'greatest-n-per-group' query. My variant on this would be to have a query that returns the first 3 rows of each category. As the basis for this I need to sort my data into a usable sequence and that is where my problems start. Running just the sequence query with row numbering shows that changes in category are mostly ignored. I should have 35 categories returning rows but only 5 do so. My query: set @c:=0; set @a:=0; SELECT IF(@c = tdg, @a:=@a+1, @a:=1) AS rownum, (@c:=tdg) , julian_day, sequence, complete, year, tdg FROM tsd WHERE complete = 0 order by tdg, year, julian_day, sequence Do I have a syntax mistake with this query?

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• How to match data between columns to do the comparasion

  - by NCC

  I do not really know how to explain this in a clear manner. Please see attached image I have a table with 4 different columns, 2 are identical to each other (NAME and QTY). The goal is to compare the differences between the QTY, however, in order to do it. I must: 1. sort the data 2. match the data item by item This is not a big deal with small table but with 10 thousand rows, it takes me a few days to do it. Pleas help me, I appreciate. My logic is: 1. Sorted the first two columns (NAME and QTY) 2. For each value of second two columns (NAME and QTY), check if it match with first two column. If true, the insert the value. 3. For values are not matched, insert to new rows with offset from the rows that are in first two columns but not in second two columns

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• How do I use python wx:Config to access the Windows registry?

  - by GreenAsJade

  I've read http://wxpython.org/docs/api/wx.ConfigBase-class.html I've done some basic things like the appended. What I can see is that Config.Create() returns me some sort of configuration object, which has information about python in it. But clearly that's not what I'm looking for: I seem to be missing the magic to say "give me a Config that is the Windows Registry"... Thanks! GaJ import wx from wx import Config app=wx.App(False) config=Config.Create() config.HasGroup("HKEY_CURRENT_USER") False config.GetFirstEntry() (0, u'', -1) config.GetFirstGroup() (1, u'PythonCore', 1) config.GetNextGroup(1) (0, u'', -1) config.GetNumberOfGroups() 1 config.GetPath() u'' config.HasEntry("PythonCore") False config.GetFirstGroup() (1, u'PythonCore', 1)

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• From Fraction to Decimal and Back?

  - by CC

  Hi folks... Is it possible to store a fraction like 3/6 in a variable of some sort? When I try this it only stores the numbers before the /. I know that I can use 2 variables and divide them, but the input is from a single text field. Is this at all possible? I want to do this because I need to calculate the fractions to decimal odds. A bonus question ;) - Is there an easy way to calculate a decimal value to a fraction? Thanks..

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• accessing variable sheet ranges within Google spreadsheet?

  - by Daniel Harvey

  I've been trying to keep this little project entirely within Google docs, but I may have hit a wall. The spreadsheet is being used as a way for multiple users to record individual events with a Template they duplicate. I want to be able to compile a list of names of those attended onto a "report" sheet from all of the unique sheets, which should be after a certain sheet index [3] to [infinite]. Is this sort of variable sheet range possible in Google spreadsheets or do I need to go to the API to get this accomplished?

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• best method for creating a universal extention/plugin

  - by rashcroft44

  Hi, I'm looking to create an extension for the leading browsers (firefox, safari and ie). Its rather simple, and I'm looking for the most efficient way to go about this. I need to get the hostname of the current site the user is on, and if it matches a certain parameter(eg, mysite.org), I'll need to append to the link some extra data and refresh to the new link. What is the simplest way to go about this? (I don't want to go in the direction of a bookmarklet - since this would require the user to click. I'd like this to happen automatically) sort of something like this: if(window.location.hostname == 'mysite.org') { location.replace(document.location.href + '/&mystuff=xyz'); } Thanks!

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• Counting variables per observation per month in Sas.

  - by John

  Hey guys, a quick question, I have data of the following sort: Ticker _ Date _ Fem Analyst (dummy 1 if true) AA _ 04/2001 _ 1 AA _ 04/2001 _ 1 AA _ 04/2001 _ 1 AA _ 05/2002 _ 1 AA _ 05/2002 _ 1 AA _ 07/2002 _ 0 AA _ 04/2003 _ 1 and so on.. What I want to receive is the following: Ticker _ Date _ Number of fem analyst AA _ 04/2001 _ 3 AA _ 05/2002 _ 2 AA _ 07/2002 _ 0 AA _ 04/2003 _ 1 So an easy counting algorithm that allows me to count for the number of analysts per company per month (the date is in 01/04/2002 format but I also have a month count variable which can be used too) Any ideas?

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• Take input through Buttons in java

  - by stash211

  I understand that the title might not be descriptive enough, but I'm making a magic square game in Java and basically, I'm trying to replicate user input as found in the sudoku game here: http://www.websudoku.com/. What I have is a n x n grid of Buttons (not JButton) as the board and what I want the user to be able to do is when the user clicks on one of the buttons, similar to the game above, it allows the user to type in his guess in the button itself instead of popping up a dialog box with an input field of some sort. I don't know where to start, I am a beginner in Java (not very beginner, but my knowledge with the various Java APIs is very limited), so I'm trying to find out if this would be possible and if it is, how would I go about doing it? Thanks for any help.

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• Hadoop Map Reduce job never finishes

  - by rohanbk

  I am running a Hadoop Map Reduce job using a Python Mapper and Reducer script, and Hadoop Streaming. Both my Map and Reduce jobs run till they are both 100%, but the job doesn't end. I know that when things go sour, Hadoop will terminate the job, but in this case, both stages reach a 100% and just never end. Has anyone else encountered anything similar? Also, how do I debug my program to figure out where things are going wrong? If I use a smaller input file, and I just run something like: $> cat input_file | mapper.py | sort | reduce.py >> output_file everything works perfectly fine. However, when I use Hadoop, things don't work out.

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