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• I'm having an issue to use GLshort for representing Vertex, and Normal.

  - by Xylopia

  As my project gets close to optimization stage, I notice that reducing Vertex Metadata could vastly improve the performance of 3D rendering. Eventually, I've dearly searched around and have found following advices from stackoverflow. Using GL_SHORT instead of GL_FLOAT in an OpenGL ES vertex array How do you represent a normal or texture coordinate using GLshorts? Advice on speeding up OpenGL ES 1.1 on the iPhone Simple experiments show that switching from "FLOAT" to "SHORT" for vertex and normal isn't tough, but what troubles me is when you're to scale back verticies to their original size (with glScalef), normals are multiplied by the reciprocal of the scale. Natural remedy for this is to multiply the normals w/ scale before you submit to GPU. Then, my short normals almost become 0, because the scale factor is usually smaller than 0. Duh! How do you use "short" for both vertex and normal at the same time? I've been trying this and that for about a full day, but I could only go for "float vertex w/ byte normal" or "short vertex w/ float normal" so far. Your help would be truly appreciated.

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• MUD (game) design concept question about timed events.

  - by mudder

  I'm trying my hand at building a MUD (multiplayer interactive-fiction game) I'm in the design/conceptualizing phase and I've run into a problem that I can't come up with a solution for. I'm hoping some more experienced programmers will have some advice. Here's the problem as best I can explain it. When the player decides to perform an action he sends a command to the server. the server then processes the command, determines whether or not the action can be performed, and either does it or responds with a reason as to why it could not be done. One reason that an action might fail is that the player is busy doing something else. For instance, if a player is mid-fight and has just swung a massive broadsword, it might take 3 seconds before he can repeat this action. If the player attempts to swing again to soon, the game will respond indicating that he must wait x seconds before doing that. Now, this I can probably design without much trouble. The problem I'm having is how I can replicate this behavior from AI creatures. All of the events that are being performed by the server ON ITS OWN, aka not as an immediate reaction to something a player has done, will have to be time sensitive. Some evil monster has cast a spell on you but must wait 30 seconds before doing it again... I think I'll probably be adding all these events to some kind of event queue, but how can I make that event queue time sensitive?

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• Iterating through Event Log Entry Collection, IndexOutOutOfBoundsException

  - by fjdumont

  Hello, in a service application I am iterating through the Windows application event log to parse Events in order react depanding on the entry message. In the case that the event log is full (Windows usually makes sure there is enough space by deleting old entries - this is configurable in the eventvwr.exe settings), the service always runs into an IndexOutOfBoundsException while iterating through the EventLog.Entries collection. No matter how I iterate (for-loop, using the collections enumerator, copying the collection into an array, ...), I can't seem to get rid of this ´bug´. Currently, I ensure that the log is not full in order to keep the service running by regularly deleting the last few item by parsing the event log file and deleting the last few nodes (Don't beat me up, I couldn't find a better alternative...). How can I iterate through the collection without trying to access already deleted entries? Is there probably a more elegant method? I am only trying to acces the logs written during the last x seconds (even LINQ failed to select those when the log is full - same exception), could this help? Thanks for any advice and hints Frank Edit: I forgot to mention that my assumption is the loops are accessing entries which are being deleted during iteration by Windows. Basically that is why I tried to clone the collection. Is there perhaps a way to lock the collection for a small amount of time for just my application?

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• Reservation Solution for RealEstate integrating with Joomla

  - by Pennf0lio

  Hi, My client needs a Property (Just Land NO Houses) Reservation solution for their existing website (It runs in Joomla). I need some advice/Tips on what approach should I use. I'm looking for an Opensource solution that I can customize to my need. The Scenario: A buyer reserves a lot, A form appears gathers his details after that he/she pays for the reservation. FrontEnd: I need a form builder extension in Joomla that I could build custom form in gathering information (name, email, contact info, address...) from the buyer or the person who is reserving it. After I gather the info I need another extension that will handle the payment for reserving it. This is kinda shopping cart type approach, you see a product and the buy it. But would just need extra details. Backend: I can see all the details of the buyer from their name to the time they paid for a reservation. Thanks! P.S. I'm open to all Ideas. I'm not sure of this approach. Please let me know If you have some good Ideas or example.

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• How can I redirect directory using htaccess including files with spaces in the names

  - by James

  Hi, I am dealing with a situation where someone has handed me a bunch of old files on the server which already have a lot of incoming links directly to them (mostly pdf files). I now have the files organized but in a different directory. Before it was 'domain/manuals/file' now it is 'domain/media/manual/file'. I am trying to resolve this issue using an htaccess file. Many of the files have spaces in the names (not something I can control) and because they already have links to them I can't just go through renaming them. I have found that I can redirect files individually when they have spaces in the names by using quotes such as: redirect 301 "/manuals/file 123.pdf" "http://www.domain.com/manuals/file 123.pdf" However, there are loads of these files and I wondered if there is a way to create a regular expression that will handle spaces in file names that I could use to redirect the entire directory. I should add that some files contain decent file names with no spaces in, some have one space and others more than one space. It's not pretty. If you've encountered this problem before I would really appreciate hearing your advice, I'm running out of ideas. Thanks.

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• routing mvc on the web

  - by generic_noob

  Hi, I was wondering if anyone could possibly provide me some advice on how i could improve the routing (and/or architecture) to each 'section' of my application. (I'm writing in PHP5, and trying to use strict MVC) Basically, I have a generic index page for the app, and that will spew out boilerplate stuff like jquery and the css etc. and it also generates the main navidation for the entire site, but i'm unsure about the best approach to connect the 'main menu' items(hyperlinks) with their associated controllers. Up until now I have been appending strings into the url and using a 'switch' statement to branch to the correct controller(and view) by extracting the strings back out of '$GET[]' to let it execute the code for the corrosponding action. for instance if i had a basic crud system for customer data, the url to edit a customers details would look like 'www.example.com/index.php?page=customer&action=edit&id=4'. I'm worried that there is a security concern by doing it this way, and i'm not sure of an alternative to branch the main 'index.php' file to the correct controller for each action once the user has clicked the link. Would it be better to use mod_rewrite to disguise the controllers names? or to create a similar system to the ASP MVC framework, where there is a seperate routing system where each url is filtered to get the associated controller? Cheers!

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• How safe and reliable are C++ String Literals?

  - by DoctorT

  So, I'm wanting to get a better grasp on how string literals in C++ work. I'm mostly concerned with situations where you're assigning the address of a string literal to a pointer, and passing it around. For example: char* advice = "Don't stick your hands in the toaster."; Now lets say I just pass this string around by copying pointers for the duration of the program. Sure, it's probably not a good idea, but I'm curious what would actually be going on behind the scenes. For another example, let's say we make a function that returns a string literal: char* foo() { // function does does stuff return "Yikes!"; // somebody's feeble attempt at an error message } Now lets say this function is called very often, and the string literal is only used about half the time it's called: // situation #1: it's just randomly called without heed to the return value foo(); // situation #2: the returned string is kept and used for who knows how long char* retVal = foo(); In the first situation, what's actually happening? Is the string just created but not used, and never deallocated? In the second situation, is the string going to be maintained as long as the user finds need for it? What happens when it isn't needed anymore... will that memory be freed up then (assuming nothing points to that space anymore)? Don't get me wrong, I'm not planning on using string literals like this. I'm planning on using a container to keep my strings in check (probably std::string). I'm mostly just wanting to know if these situations could cause problems either for memory management or corrupted data.

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• PHP/Javascript limiting amount of checkboxes

  - by Carl294

  Hi everyone Im trying to limit the amount of checkboxes that can be checked, in this case only 3 can be checked. When using plain HTML this works fine. The code can be seen below. HTML example <td ><input type=checkbox name=ckb value=2 onclick='chkcontrol()';></td><td>Perl</td> Javascript Function <script type="text/javascript"> function chkcontrol(j) { var total=0; for(var i=0; i < document.form1.ckb.length; i++){ if(document.form1.ckb[i].checked){ total =total +1;} if(total > 3){ alert("Please Select only three") document.form1.ckb[j].checked = false; return false; } } } </script> The problem appears when replacing the fixed HTML values with values from a MYSQL database. All the information appears correctly, and can be posted to another page via a submit button. However, it seems like the 'value' assigned to each record from the database is not making its way too the javascript function. <td><input name="checkbox[]" type="checkbox" value="<?php echo $rows['TCA_QID'];?>" onclick="chkcontrol();"></td> I have tried changed the name in the javascript function to match the 'checkbox' name.Any advice would be greatly appreciated Thanks

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• Web pages that a long time to load keep on reloading, just on vista on my work n/w...

  - by Ralpharama

  I have a curious problem at work which I've been struggling with since the advent of Windows Vista. We send our own email newsletter out to 40,000+ people once a week. The sending code has been in place for years, it's in classic ASP/VBscript called through a browser and simply loops through each email address, sending it to them. The page takes 40 mins or more to run, so has a big timeout value to allow it to do so. All well and good, suddenly, after Windows Vista is installed on the work PCs, the email sending page behaved oddly - after a period of time it seems to reload the page, endlessly, so the first 20% of our users get multiple copies of the newsletter until we kill the process! If we run the code on an XP machine in the on the same office network, it works fine. If we run it on Vista outside the office, so, say, on my own ISP, then it also works fine! Note, same effect in IE and FF... So, something about my office network and Vista is causing this... I recently re-wrote the newsletter code so it would split the task into chunks of 100 users at a time, hoping this would fix it, but my most recent test shows that the office n/w vista machine once again reloads the same page over any over, even though it takes 1/10th of the time to run... Does anyone have any ideas what it might be, how I can prove it, or, better, how I can get round it? Thanks for your advice :)

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• String literal recognition problem

  - by helicera

  Hello! I'm trying to recognize string literal by reading string per symbol. Here is a sample code: #region [String Literal (")] case '"': // {string literal ""} { // skipping '"' ChCurrent = Line.ElementAtOrDefault<Char>(++ChPosition); while(ChCurrent != '"') { Value.Append(ChCurrent); ChCurrent = Line.ElementAtOrDefault<Char>(++ChPosition); if(ChCurrent == '"') { // "" sequence only acceptable if(Line.ElementAtOrDefault<Char>(ChPosition + 1) == '"') { Value.Append(ChCurrent); // skip 2nd double quote ChPosition++; // move position next ChCurrent = Line.ElementAtOrDefault<Char>(++ChPosition); } } else if(default(Char) == ChCurrent) { // message: unterminated string throw new ScanningException(); } } ChPosition++; break; } #endregion When I run test: [Test] [ExpectedException(typeof(ScanningException))] public void ScanDoubleQuotedStrings() { this.Scanner.Run(@"""Hello Language Design""", default(System.Int32)); this.Scanner.Run(@"""Is there any problems with the """"strings""""?""", default(System.Int32)); this.Scanner.Run(@"""v#:';?325;.<>,|+_)""(*&^%$#@![]{}\|-_=""", default(System.Int32)); while(0 != this.Scanner.TokensCount - 1) { Assert.AreEqual(Token.TokenClass.StringLiteral, this.Scanner.NextToken.Class); } } It passes with success.. while I'm expecting to have an exception according to unmatched " mark in this.Scanner.Run(@"""v#:';?325;.<>,|+_)""(*&^%$#@![]{}\|-_=""", default(System.Int32)); Can anyone explain where is my mistake or give an advice on algorithm.

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• Is the REST support in Spring 3's MVC Framework production quality yet?

  - by glenjohnson

  Hi all, Since Spring 3 was released in December last year, I have been trying out the new REST features in the MVC framework for a small commercial project involving implementing a few RESTful Web Services which consume XML and return XML views using JiBX. I plan to use either Hibernate or JDBC Templates for the data persistence. As a Spring 2.0 developer, I have found Spring 3's (and 2.5's) new annotations way of doing things quite a paradigm shift and have personally found some of the new MVC annotation features difficult to get up to speed with for non-trivial applications - as such, I am often having to dig for information in forums and blogs that is not apparent from going through the reference guide or from the various Spring 3 REST examples on the web. For deadline-driven production quality and mission critical applications implementing a RESTful architecture, should I be holding off from Spring 3 and rather be using mature JSR 311 (JAX-RS) compliant frameworks like RESTlet or Jersey for the REST layer of my code (together with Spring 2 / 2.5 to tie things together)? I had no problems using RESTlet 1.x in a previous project and it was quite easy to get up to speed with (no magic tricks behind the scenes), but when starting my current project it initially looked like the new REST stuff in Spring 3's MVC Framework would make life easier. Do any of you out there have any advice to give on this? Does anyone know of any commercial / production-quality projects using, or having successfully delivered with, the new REST stuff in Spring 3's MVC Framework. Many thanks Glen

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• How to read time from recorded surveillance camera video?

  - by stressed_geek

  I have a problem where I have to read the time of recording from the video recorded by a surveillance camera. The time shows up on the top-left area of the video. Below is a link to screen grab of the area which shows the time. Also, the digit color(white/black) keeps changing during the duration of the video. http://i55.tinypic.com/2j5gca8.png Please guide me in the direction to approach this problem. I am a Java programmer so would prefer an approach through Java. EDIT: Thanks unhillbilly for the comment. I had looked at the Ron Cemer OCR library and its performance is much below our requirement. Since the ocr performance is less than desired, I was planning to build a character set using the screen grabs for all the digits, and using some image/pixel comparison library to compare the frame time with the character-set which will show a probabilistic result after comparison. So I was looking for a good image comparison library(I would be OK with a non-java library which I can run using the command-line). Also any advice on the above approach would be really helpful.

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• Javascript XMLHttpRequest Post method

  - by user535617

  Hey So I have a question about posting using an XMLHttpRequest. In theory, if I am to post a username and password to an https domain (which I have yet to get working, unfortunately) would the responseText then change to the next website, or should the text fields become filled in? What normally happens is you navigate to this page via browser, enter a username and password, and it uses a POST method when the submit button is clicked, doing some authentication under the hood and returning a different page. I feel like maybe the responseText should even stay exactly the same (which is what happens now), but I don't know as I have no experience with this kind of thing. this.requests[1].open("POST", "https://" + this.address, true); var query = "target=%2Fcgi-bin%2FStatusConfig.cgi%3FPage%3Dindex&userfile=&username=user&password=pass&log+in=Log+in"; this.requests[1].setRequestHeader("Content-Type", "application/x-www-form-urlencoded"); this.requests[1].setRequestHeader("Content-length", query.length); this.requests[1].setRequestHeader("Keep-Alive", 115); this.requests[1].setRequestHeader("Connection", "keep-alive"); this.requests[1].setRequestHeader("Host", this.address); this.requests[1].send(query); this.requests[1].onreadystatechange = onReadyStateChange1; Then basically onReadyStateChange1 displays the responseText when ready. Any light that could be shed on what SHOULD be happening with the post and responseText would be very appreciated. As would any advice in getting the new, logged into page. For further clarification, what I'm trying to do is log in and then return the new page, because the login page displays only log in information/functionality and the page after logging in has a lot of relevant information. I'm not trying to check the credentials as much as I'm trying to get it (the script) to log in so it can access the next page. Granted, the credentials will have to be valid for that. Thanks all.

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• Extract data from PostgreSQL DB without using pg_dump

  - by John Horton

  There is a PostgreSQL database on which I only have limited access (e.g, I can't use pg_dump). I am trying to create a local "mirror" by exporting certain tables from the database. I do not have the permissions needed to just dump a table as SQL from within psql. Right now, I just have a Python script that iterates through my table_names, selects all fields and then exports them as a CSV: for table_name, file_name in zip(table_names, file_names): cmd = """echo "\\\copy (select * from %s)" to stdout WITH CSV HEADER | psql -d remote_db | gzip > ./%s/%s.gz"""%(table_name,dir_name,file_name) os.system(cmd) I would like to not use CSV if possible, as I lose the field types and the encoding can get messed up. First best would probably be some way of getting the generating SQL code for the table using \copy. Next best would be XML, ideally with some way of preserving the field types. If that doesn't work, I think the final option might be two queries---one to get the field data types, the other to get the actual data. Any thoughts or advice would be greatly appreciated - thanks!

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• Is XSLT worth investing time in and are there any actual alternatives?

  - by Keeno

  I realize this has been a few other questions on this topic, and people are saying use your language of choice to manipulate the XML etc etc however, not quite fit my question exactly. Firstly, the scope of the project: We want to develop platform independent e-learning, currently, its a bunch of HTML pages but as they grow and develop they become hard to maintain. The idea: Generate up an XML file + Schema, then produce some XSLT files that process the XML into the eLearning modiles. XML to HTML via XSLT. Why: We would like the flexibilty to be able to easy reformat the content (I realize CSS is a viable alternative here) If we decide to alter the pages layout or functionality in anyway, im guessing altering the "shared" XSLT files would be easier than updating the HTML files. So far, we have about 30 modules, with up to 10-30 pages each Depending on some "parameters" we could output drastically different page layouts/structures, above and beyond what CSS can do Now, all this has to be platform independent, and to be able to run "offline" i.e. without a server powering the HTML Negatives I've read so far for XSLT: Overhead? Not exactly sure why...is it the compute power need to convert to HTML? Difficult to learn Better alternatives Now, what I would like to know exactly is: are there actually any viable alternatives for this "offline"? Am I going about it in the correct manner, do you guys have any advice or alternatives. Thanks!

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• Trait, FunctionN, or trait-inheriting-FunctionN in Scala?

  - by Willis Blackburn

  I have a trait in Scala that has a single method. Call it Computable and the single method is compute(input: Int): Int. I can't figure out whether I should Leave it as a standalone trait with a single method. Inherit from (Int = Int) and rename "compute" to "apply." Just get rid of Computable and use (Int = Int). A factor in favor of it being a trait is that I could usefully add some additional methods. But of course if they were all implemented in terms of the compute method then I could just break them out into a separate object. A factor in favor of just using the function type is simplicity and the fact that the syntax for an anonymous function is more concise than that for an anonymous Computable instance. But then I've no way to distinguish objects that are actually Computable instances from other functions that map Int to Int but aren't meant to be used in the same context as Computable. How do other people approach this type of problem? No right or wrong answers here; I'm just looking for advice.

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• Load PEM encoded private RSA key in Crypto++

  - by 01100110

  Often times, user will have PEM encoded RSA private keys. Crypto++ requires that these keys be in DER format to load. I've been asking people to manually convert their PEM files to DER beforehand using openssl like this: openssl pkcs8 -in in_file.pem -out out_file.der -topk8 -nocrypt -outform der That works fine, but some people don't understand how to do that nor do they want to. So I would like to convert PEM files to DER files automatically within the program. Is it as simple as striping the "-----BEGIN CERTIFICATE-----" and "-----END CERTIFICATE-----" from the PEM or is some other transformation required as well? I've been told that between those markers that it's just b64 encoded DER. Here's some code that demonstrates the issue: // load the private key CryptoPP::RSA::PrivateKey PK; CryptoPP::ByteQueue bytes; try { CryptoPP::FileSource File( rsa.c_str(), true, new CryptoPP::Base64Decoder() ); File.TransferTo( bytes ); bytes.MessageEnd(); // This line Causes BERDecodeError when a PEM encoded file is used PK.Load( bytes ); } catch ( CryptoPP::BERDecodeErr ) { // Convert PEM to DER and try to load the key again } I'd like to avoid making system calls to openssl and do the transformation entirely in Crypto++ so that users can provide either format and things "just work". Thanks for any advice.

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• Mysql Performance Question - Essentially about normalizing efficiency

  - by freqmode

  Hi there. Just a quick question about database performance. I'll outline my site purpose below as background. I'm creating a dictionary site that saves the words users define to a database. What I'm wondering is whether or not to create a words table for each user or to keep one massive words table. This site will be used for entire schools so the single words table would be massive! The database structure is as follows: A user table with: User_ID PRIMARY KEY Username First Last Password Email Country Research Standings SendInfo Donated JoinedOn LastLogin Logins Correct Attempts Admin Active And one word table with: User_ID PRIMARY KEY Word Vocab Spell Defined DefinedAttempted Spelled SpelledAttempted Sentenced SentencedAttempted So what I'm asking is , performance-wise, should I create a new table for each user when they join the site - each user could have hundreds or thousands of words over time? Or is it better to have one massive table with thousands and thousands of records and filter by User_ID. I don't think I'll perform many table joins. My gut feeling is to create a new table for each user, but I thought I'd ask for expert advice! Thanks in advance.

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• Wrong date with ruby Date.today and DateTime.now

  - by Rob

  I've installed ruby-1.8.6-p383 with RVM. System ruby is 1.9.1_p378-1 I'm getting the wrong date from Date.today and DateTime.now when using ruby 1.8.. Whereas Time.now is correct: irb(main):002:0> DateTime.now.to_s => "2126--1-10618T11:23:43+00:00" irb(main):004:0> Date.today.to_s => "2126--1-10618" irb(main):005:0> Time.now => Thu Jan 28 11:55:27 +0000 2010 All is well if I switch to ruby 1.9: irb(main):003:0> DateTime.now.to_s => "2010-01-28T11:58:51+00:00" irb(main):004:0> Date.today.to_s => "2010-01-28" irb(main):005:0> Time.now => 2010-01-28 11:59:05 +0000 Any advice on how to get DateTime to work properly in ruby 1.8 would be most appreciated!

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• Timer appears to be pausing when screen becomes inactive

  - by elchuppa

  So I have a very simple android activity that starts a timer when you hit a button. Timer timer = new Timer(); timer.schedule(new TimerTask() { @Override public void run() { doStuff(); } }, 15 * 60 * 1000); So this worked reasonably well for me when I was testing but as it turns out when the screen becomes inactive so does the timer. I was a bit surprised by this. I understand you need to create a service to have anything running in the background but I hadn't realized this is required for an activity in the foreground when the phone has inactivated the screen due to lack of activity. What confuses me is I think this worked as I expected originally and just in the last few weeks or so has the timer been affected by the phone saving power. I could be wrong though.. So basically my questions are: am I seeing expected behavior? Do I need to create all timers as services or somehow disallow powersaving? thanks for any advice, Patrick

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• CakePHP Routes: Messing With The MVC

  - by thesunneversets

  So we have a real-estate-related site that has controller/action pairs like "homes/view", "realtors/edit", and so forth. From on high it has been deemed a good idea to refactor the site so that URLS are now in the format "/realtorname/homes/view/id", and perhaps also "/admin/homes/view/id" and/or "/region/..." As a mere CakePHP novice I'm finding it difficult to achieve this in routes.php. I can do the likes of: Router::connect('/:filter/h/:id', array('controller'=>'homes','action'=>'view')); Router::connect('/admin/:controller/:action/:id'); But I'm finding that the id is no longer being passed simply and elegantly to the actions, now that controller and action do not directly follow the domain. Therefore, questions: Is it a stupid idea to play fast and loose with the /controller/action format in this way? Is there a better way of stating these routes so that things don't break egregiously? Would we be better off going back to subdomains (the initial method of achieving this type of functionality, shot down on potentially spurious SEO-related grounds)? Many thanks for any advice! I'm sorry that I'm such a newbie that I don't know whether I'm asking stupid questions or not....

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• C# "Rename" Property in Derived Class

  - by Eric

  When you read this you'll be awfully tempted to give advice like "this is a bad idea for the following reason..." Bear with me. I know there are other ways to approach this. This question should be considered trivia. Lets say you have a class "Transaction" that has properties common to all transactions such as Invoice, Purchase Order, and Sales Receipt. Let's take the simple example of Transaction "Amount", which is the most important monetary amount for a given transaction. public class Transaction { public double Amount { get; set; } public TxnTypeEnum TransactionType { get; set; } } This Amount may have a more specific name in a derived type... at least in the real world. For example, the following values are all actually the same thing: Transaction - Amount Invoice - Subtotal PurchaseOrder - Total Sales Receipt - Amount So now I want a derived class "Invoice" that has a Subtotal rather than the generically-named Amount. Ideally both of the following would be true: In an instance of Transaction, the Amount property would be visible. In an instance of Invoice, the Amount property would be hidden, but the Subtotal property would refer to it internally. Invoice looks like this: public class Invoice : Transaction { new private double? Amount { get { return base.Amount; } set { base.Amount = value; } } // This property should hide the generic property "Amount" on Transaction public double? SubTotal { get { return Amount; } set { Amount = value; } } public double RemainingBalance { get; set; } } But of course Transaction.Amount is still visible on any instance of Invoice. Thanks for taking a look!

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• Which is faster for large "for" loop: function call or inline coding?

  - by zaplec

  Hi, I have programmed an embedded software (using C of course) and now I'm considering ways to improve the running time of the system. The most important single module in my system is one very large nested for loop module. That module consists of two nested for loops that loops max 122500 times. That's not very much yet, but the problem is that inside that nested for loop I have a function call to a function that is in another source file. That specific function consists mostly of two another nested for loops which loops always 22500 times. So now I have to make a function call 122500 times. I have made that function that is to be called a lot lighter and shorter (yet still works as it should) and now I started to think that would it be faster to rip off that function call and write that process directly inside those first two for loops? The processor in that system is ARM7TDMI and its frequency is 55MHz. The system itself isn't very time critical so it doesn't have to be real time capable. However the faster it can process its duties the better. Also would it be also faster to use while loops instead of fors? And any piece of advice about how to improve the running time is appreciated. -zaplec

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• Significance in R

  - by Gemsie

  Ok, this is quite hard to explain, but I'm at a complete loss what to do. I'm a relative newcomer to R and although I can completely admire how powerful it is, I'm not too good at actually using it.... Basically, I have some very contrived data that I need to analyse (it wasn't me who chose this, I can assure you!). I have the right and left hand lengths of lots of people, as well as some numeric data that shows their sociability. Now I would like to know if people who have significantly different lengths of hand are more or less sociable than those who have the same (leading into the research that 'symmetrical' people are more sociable and intelligent, etc. I have got as far as loading the data into R, then I have no idea where to go from there. How on Earth do I start to separate those who are close to symmetrical to those who aren't to then start to do the analysis? Ok, using Sasha's great advice, I did the cor.test and got the following: Pearson's product-moment correlation data: measurements$l.hand - measurements$r.hand and measurements$sociable t = 0.2148, df = 150, p-value = 0.8302 alternative hypothesis: true correlation is not equal to 0 95 percent confidence interval: -0.1420623 0.1762437 sample estimates: cor 0.01753501 I have never used this test before, so am unsure how to intepret it...you wouldn't think I was on my fourth Scientific degree would you?! :(

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• Python Speeding Up Retrieving data from extremely large string

  - by Burninghelix123

  I have a list I converted to a very very long string as I am trying to edit it, as you can gather it's called tempString. It works as of now it just takes way to long to operate, probably because it is several different regex subs. They are as follow: tempString = ','.join(str(n) for n in coords) tempString = re.sub(',{2,6}', '_', tempString) tempString = re.sub("[^0-9\-\.\_]", ",", tempString) tempString = re.sub(',+', ',', tempString) clean1 = re.findall(('[-+]?[0-9]*\.?[0-9]+,[-+]?[0-9]*\.?[0-9]+,' '[-+]?[0-9]*\.?[0-9]+'), tempString) tempString = '_'.join(str(n) for n in clean1) tempString = re.sub(',', ' ', tempString) Basically it's a long string containing commas and about 1-5 million sets of 4 floats/ints (mixture of both possible),: -5.65500020981,6.88999986649,-0.454999923706,1,,,-5.65500020981,6.95499992371,-0.454999923706,1,,, The 4th number in each set I don't need/want, i'm essentially just trying to split the string into a list with 3 floats in each separated by a space. The above code works flawlessly but as you can imagine is quite time consuming on large strings. I have done a lot of research on here for a solution but they all seem geared towards words, i.e. swapping out one word for another. EDIT: Ok so this is the solution i'm currently using: def getValues(s): output = [] while s: # get the three values you want, discard the 3 commas, and the # remainder of the string v1, v2, v3, _, _, _, s = s.split(',', 6) output.append("%s %s %s" % (v1.strip(), v2.strip(), v3.strip())) return output coords = getValues(tempString) Anyone have any advice to speed this up even farther? After running some tests It still takes much longer than i'm hoping for. I've been glancing at numPy, but I honestly have absolutely no idea how to the above with it, I understand that after the above has been done and the values are cleaned up i could use them more efficiently with numPy, but not sure how NumPy could apply to the above. The above to clean through 50k sets takes around 20 minutes, I cant imagine how long it would be on my full string of 1 million sets. I'ts just surprising that the program that originally exported the data took only around 30 secs for the 1 million sets

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