Search Results

Search found 15137 results on 606 pages for 'mean filter'.

Page 515/606 | < Previous Page | 511 512 513 514 515 516 517 518 519 520 521 522  | Next Page >

• Is a confirmation screen necessary for an order form?

  - by abeger

  In a discussion about how to streamline an order form on our site, the idea of eliminating the confirmation screen. So, instead of filling out the form, clicking "Submit", seeing a summary on a confirmation screen and clicking "Confirm", the user would simply fill out the form, hit "Submit", and the order's done. The theory is that fewer clicks and fewer screens means less time to order and therefore the ordering experience is easier. The opposing opinion says that without the confirmation screen, user error increases and people just end up canceling/changing orders after the fact. I'm looking for more input from the SO community. Have you ever done this? How has it worked out, compared to a traditional confirmation screen setup? Are there examples of a true "one click and done" setup on the web (does Amazon's 1-click have a confirmation screen? I've never been courageous enough to try it)? EDIT: Just to clarify, when I say "confirmation screen", I mean a second step where the customer reviews the order before placing it. Even if we did do away with it, the user would still receive a message saying "your order has been placed".

  Read the article

• Find & Replace - using a Regex for this?

  - by Jack W-H

  Hey folks. Regexs make me cry, so, I came here for help. I'm looking for some tips on Find & Replace in Panic's Coda. I know the F&R is pretty advance but I'm just looking for the best way to do this. I'm trying to rewrite a 'template engine' (very basic) I have going on with a webapp I'm coding in PHP (CodeIgniter). Currently I'm calling my template like so: $this->load->view('subviews/template/headerview'); $this->load->view('subviews/template/menuview'); $this->load->view('subviews/template/sidebar'); $this->load->view('The-View-I-Want-To-Load'); // This is the important line $this->load->view('subviews/template/footerview'); However it's inefficient using five lines of code every time I want to load up a different page, in every different controller. So I rewrote it like this: $data['view'] = 'The-View-I-Want-To-Load'; $this->load->view('template',$data); That way if I need to make any major changes to the design it can easily be done from the template.php view file (which contains the header, menu, sidebar views etc. etc.). However I use the previous 5-lines all over the place in many different controllers and functions. So, my question is --- How can I find and replace the old template engine (5 lines of code) for the new one - substituting in the name of the view in the important, unique line for the one in $data['view]? Does that make any sense?! If not I'll try and rephrase! I mean, is there a way of doing this via a Regex or something? Or am I on completely the wrong lines here? Thanks for your help Jack

  Read the article

• nhibernate - mapping with contraints

  - by Tobias Müller

  Hello everybody, I am having a Problem with my nhibernate-mapping and I can't find a solution by searching on stackoverflow/google/documentation. The database I am using has (amongst others) two tables. One is unit with the following fields: id enduring_id starts ends damage_enduring_id [...] The other one is damage, which has the following fields: id enduring_id starts ends [...] The units are assigned to a damage and one damage can have zero, one or more units working on it. Every time a unit moves to annother damage, the dataset is copied. The field "ends" of the old record and "starts" of the new record are set to the current time stamp, enduring_id stays the same. So if I want to know which units were working on a damage at a certain time, I do the following select: select * from unit join damage on damage.enduring_id = unit.damage_enduring_id where unit.starts <= 'time' and unit.ends = 'time' (This is not an actualy query from the database, I made it up to make clear what I mean. The the real database is a little more complex) Now I want to map it that way, so I can load all the damages which are valid at one time (starts <= wanted time <= ends) and that each of them has a Bag with all the attached units at that time (again starts <= wanted time <= ends). Is this possible within the mapping? Sorry if this is a stupid question, but I am pretty new to nhibernate and I have no clue how to do it. Thanks a lot for reading my post! Bye, Tobias

  Read the article

• Inside what the TexBox value is posted back? ViewState or post back data?

  - by burak ozdogan

  In one article I was reading on ViewState, I saw a sentence saying that I should not fall into a mistake to believe that the value of a TextBox is stored in ViewState; it is stored in PostBack data. From here what I understand is when I post back a web form, the input controls values are stored in HTTP Request body. Not in the Viewstate. But as far as I know ViewState values are stored in an hidden field called __VIEWSTATE anyway. Then does it mean that __VIEVSTATE value is not posted in HTTP POST Request body as a postback data? Sounds nonesense to me. In another words, basically if I say the ViewState mechanism for such scenerio works like this, am I seeing it right or skipping something: You enter a value on an empty TextBox and submit the page The value of text box is posted back inside POST HTTP Request body. Nothing inside __VIEWSTATE at this point from the TextBox On the server side, the TextBox is created with the default value on OnInit method of the page The TrackChange property of ViewState is set to true. The posted back data of TextBox is loaded. Because it is different than the TextBox defalut value(because the user entered something), the ViewState of this text box is marked as DIRTY. The new value of the textbox is written into __VIEWSTATE hidden field From now on __VIEWSTATE hiddenfeild contains the last given value of the TextBox The page is sent to the user's browser having the __VIEWSTATE hidden field. But this time containing the last value entered by user which will be ready to be rendered Thanks guys! burak ozdogan

  Read the article

• SQL Alchemy MVC and cross controller joins

  - by Khorkrak

  When using SQL Alchemy for abstracting your data access layer and using controllers as the way to access objects from that abstraction layer, how should joins be handled? So for example, say you have an Orders controller class that manages Order objects such that it provides getOrder, saveOrder, etc methods and likewise a similar controller for User objects. First of all do you even need these controllers? Should you instead just treat SQL Alchemy as "the" thing for handling data access. Why bother with object oriented controller stuff there when you instead have a clean declarative way to obtain and persist objects without having to write SQL directly either. Well one reason could be that perhaps you may want to replace SQL Alchemy with direct SQL or Storm or whatever else. So having controller classes there to act as an intermediate layer helps limit what would need to change then. Anyway - back to the main question - so assuming you have these two controllers, now lets say you want the list of orders for a certain set of users meeting some criteria. How do you go about doing this? Generally you don't want the controllers crossing domains - the Orders controllers knows only about Orders and the User controller just about Users - they don't mess with each other. You also don't want to go fetch all the Users that match and then feed a big list of user ids to the Orders controller to go find the matching Orders. What's needed is a join. Here's where I'm stuck - that seems to mean either the controllers must cross domains or perhaps they should be done away with altogether and you simply do the join via SQL Alchemy directly and get the resulting User and / or Order objects as needed. Thoughts?

  Read the article

• R: How to remove outliers from a smoother in ggplot2?

  - by John

  I have the following data set that I am trying to plot with ggplot2, it is a time series of three experiments A1, B1 and C1 and each experiment had three replicates. I am trying to add a stat which detects and removes outliers before returning a smoother (mean and variance?). I have written my own outlier function (not shown) but I expect there is already a function to do this, I just have not found it. I've looked at stat_sum_df("median_hilow", geom = "smooth") from some examples in the ggplot2 book, but I didn't understand the help doc from Hmisc to see if it removes outliers or not. Is there a function to remove outliers like this in ggplot, or where would I amend my code below to add my own function? library (ggplot2) data = data.frame (day = c(1,3,5,7,1,3,5,7,1,3,5,7,1,3,5,7,1,3,5,7,1,3,5,7,1,3,5,7,1,3,5,7,1,3,5,7), od = c( 0.1,1.0,0.5,0.7 ,0.13,0.33,0.54,0.76 ,0.1,0.35,0.54,0.73 ,1.3,1.5,1.75,1.7 ,1.3,1.3,1.0,1.6 ,1.7,1.6,1.75,1.7 ,2.1,2.3,2.5,2.7 ,2.5,2.6,2.6,2.8 ,2.3,2.5,2.8,3.8), series_id = c( "A1", "A1", "A1","A1", "A1", "A1", "A1","A1", "A1", "A1", "A1","A1", "B1", "B1","B1", "B1", "B1", "B1","B1", "B1", "B1", "B1","B1", "B1", "C1","C1", "C1", "C1", "C1","C1", "C1", "C1", "C1","C1", "C1", "C1"), replicate = c( "A1.1","A1.1","A1.1","A1.1", "A1.2","A1.2","A1.2","A1.2", "A1.3","A1.3","A1.3","A1.3", "B1.1","B1.1","B1.1","B1.1", "B1.2","B1.2","B1.2","B1.2", "B1.3","B1.3","B1.3","B1.3", "C1.1","C1.1","C1.1","C1.1", "C1.2","C1.2","C1.2","C1.2", "C1.3","C1.3","C1.3","C1.3")) > data day od series_id replicate 1 1 0.10 A1 A1.1 2 3 1.00 A1 A1.1 3 5 0.50 A1 A1.1 4 7 0.70 A1 A1.1 5 1 0.13 A1 A1.2 6 3 0.33 A1 A1.2 7 5 0.54 A1 A1.2 8 7 0.76 A1 A1.2 9 1 0.10 A1 A1.3 10 3 0.35 A1 A1.3 11 5 0.54 A1 A1.3 12 7 0.73 A1 A1.3 13 1 1.30 B1 B1.1 This is what I have so far and is working nicely, but outliers are not removed: r <- ggplot(data = data, aes(x = day, y = od)) r + geom_point(aes(group = replicate, color = series_id)) + # add points geom_line(aes(group = replicate, color = series_id)) + # add lines geom_smooth(aes(group = series_id)) # add smoother, average of each replicate

  Read the article

• Development/runtime Licensing mechanism for a C# class library?

  - by Darryl

  I'm developing a .Net class library (a data provider) and I'm starting to think about how I would handle licensing the library to prospective purchasers. By licensing, I mean the mechanics of trying to prevent my library from being used by those who haven't purchased it, not the software license (i.e., Apache, Gnu, etc). I've never dealt with licensing, and in the past, I've always developed apps, not libraries. I don't want to make things difficult for my customers; know it is not possible to make it ironclad. Just some mechanism that gives me decent protection without making the customer jump through hoops or gnash their teeth. I think the mechanism would check for a valid license when the class is being used in development mode, and not in runtime mode (when the customer's software is released to their customers). I think libraries are typically sold per developer, but I'm not sure how that could be accomplished without making the mechanism odious for my customers; maybe that gets left to the honor system. I Googled this and found many approaches. Ideally, I'd like to do something that is generally accepted and common, the "right" way class libraries are licensed, if that exists, rather than making my customers deal with yet another license mechanism. A firm push in the right direction will be greatly appreciated!

  Read the article

• JavaScript: count minimal length of characters in text, ignoring special codes inside

  - by ilnur777

  I want to ignore counting the length of characters in the text if there are special codes inside in textarea. I mean not to count the special codes characters in the text. I use special codes to define inputing smileys in the text. I want to count only the length of the text ignoring special code. Here is my approximate code I tried to write, but can't let it work: // smileys // ======= function smileys(){ var smile = new Array(); smile[0] = "[:rolleyes:]"; smile[1] = "[:D]"; smile[2] = "[:blink:]"; smile[3] = "[:unsure:]"; smile[4] = "[8)]"; smile[5] = "[:-x]"; return(smile); } // symbols length limitation // ========================= function minSymbols(field){ var get_smile = smileys(); var text = field.value; for(var i=0; i<get_smile.length; i++){ for(var j=0; j<(text.length); j++){ if(get_smile[i]==text[j]){ text = field.value.replace(get_smile[i],""); } } } if(text.length < 50){ document.getElementById("saveB").disabled=true; } else { document.getElementById("saveB").disabled=false; } } How the script should be in order to let it work? Thank you!

  Read the article

• Caching sitemaps in django

  - by michuk

  I implemented a simple sitemap class using django's default sitemap app. As it was taking a long time to execute, I added manual caching: class ShortReviewsSitemap(Sitemap): changefreq = "hourly" priority = 0.7 def items(self): # try to retrieve from cache result = get_cache(CACHE_SITEMAP_SHORT_REVIEWS, "sitemap_short_reviews") if result!=None: return result result = ShortReview.objects.all().order_by("-created_at") # store in cache set_cache(CACHE_SITEMAP_SHORT_REVIEWS, "sitemap_short_reviews", result) return result def lastmod(self, obj): return obj.updated_at The problem is that memcache allows only max 1MB object. This one was bigger that 1MB, so storing into cache failed: >7 SERVER_ERROR object too large for cache The problem is that django has an automated way of deciding when it should divide the sitemap file into smalled ones. According to the docs (http://docs.djangoproject.com/en/dev/ref/contrib/sitemaps/): You should create an index file if one of your sitemaps has more than 50,000 URLs. In this case, Django will automatically paginate the sitemap, and the index will reflect that. What do you think would be the best way to enable caching sitemaps? - Hacking into django sitemaps framework to restrict a single sitemap size to, let's say, 10,000 records seems like the best idea. Why was 50,000 chosen in the first place? Google advice? random number? - Or maybe there is a way to allow memcached store bigger files? - Or perhaps onces saved, the sitemaps should be made available as static files? This would mean that instead of caching with memcached I'd have to manually store the results in the filesystem and retrieve them from there next time when the sitemap is requested (perhaps cleaning the directory daily in a cron job). All those seem very low level and I'm wondering if an obvious solution exists...

  Read the article

• Code bacteria: evolving mathematical behavior

  - by Stefano Borini

  It would not be my intention to put a link on my blog, but I don't have any other method to clarify what I really mean. The article is quite long, and it's in three parts (1,2,3), but if you are curious, it's worth the reading. A long time ago (5 years, at least) I programmed a python program which generated "mathematical bacteria". These bacteria are python objects with a simple opcode-based genetic code. You can feed them with a number and they return a number, according to the execution of their code. I generate their genetic codes at random, and apply an environmental selection to those objects producing a result similar to a predefined expected value. Then I let them duplicate, introduce mutations, and evolve them. The result is quite interesting, as their genetic code basically learns how to solve simple equations, even for values different for the training dataset. Now, this thing is just a toy. I had time to waste and I wanted to satisfy my curiosity. however, I assume that something, in terms of research, has been made... I am reinventing the wheel here, I hope. Are you aware of more serious attempts at creating in-silico bacteria like the one I programmed? Please note that this is not really "genetic algorithms". Genetic algorithms is when you use evolution/selection to improve a vector of parameters against a given scoring function. This is kind of different. I optimize the code, not the parameters, against a given scoring function.

  Read the article

• Refining data stored in SQLite - how to join several contacts?

  - by Krab

  Problem background Imagine this problem. You have a water molecule which is in contact with other molecules (if the contact is a hydrogen bond, there can be 4 other molecules around my water). Like in the following picture (A, B, C, D are some other atoms and dots mean the contact). A B . . O / \ H H . . C D I have the information about all the dots and I need to eliminate the water in the center and create records describing contacts of A-C, A-D, A-B, B-C, B-D, and C-D. Database structure Currently, I have the following structure in the database: Table atoms: "id" integer PRIMARY KEY, "amino" char(3) NOT NULL, (HOH for water or other value) other columns identifying the atom Table contacts: "acceptor_id" integer NOT NULL, (the atom near to my hydrogen, here C or D) "donor_id" integer NOT NULL, (here A or B) "directness" char(1) NOT NULL, (this should be D for direct and W for water-mediated) other columns about the contact, such as the distance Current solution (insufficient) Now, I'm going through all the contacts which have donor.amino = "HOH". In this sample case, this would select contacts from C and D. For each of these selected contacts, I look up contacts having the same acceptor_id as is the donor_id in the currently selected contact. From this information, I create the new contact. At the end, I delete all contacts to or from HOH. This way, I am obviously unable to create C-D and A-B contacts (the other 4 are OK). If I try a similar approach - trying to find two contacts having the same donor_id, I end up with duplicate contacts (C-D and D-C). Is there a simple way to retrieve all six contacts without duplicates? I'm dreaming about some one page long SQL query which retrievs just these six wanted rows. :-) It is preferable to conserve information about who is donor where possible, but not strictly necessary. Big thanks to all of you who read this question to this point.

  Read the article

• Does this mimic perfectly a function template specialization?

  - by zeroes00

  Since the function template in the following code is a member of a class template, it can't be specialized without specializing the enclosing class. But if the compiler's full optimizations are on (assume Visual Studio 2010), will the if-else-statement in the following code get optimized out? And if it does, wouldn't it mean that for all practical purposes this IS a function template specialization without any performance cost? template<typename T> struct Holder { T data; template<int Number> void saveReciprocalOf(); }; template<typename T> template<int Number> void Holder<T>::saveReciprocalOf() { //Will this if-else-statement get completely optimized out if(Number == 0) data = (T)0; else data = (T)1 / Number; } //----------------------------------- void main() { Holder<float> holder; holder.saveReciprocalOf<2>(); cout << holder.data << endl; }

  Read the article

• Calculating bounding box a certain distance away from a lat/long coordinate in Java

  - by Bryce Thomas

  Given a coordinate (lat, long), I am trying to calculate a square bounding box that is a given distance (e.g. 50km) away from the coordinate. So as input I have lat, long and distance and as output I would like two coordinates; one being the south-west (bottom-left) corner and one being the north-east (top-right) corner. I have seen a couple of answers on here that try to address this question in Python, but I am looking for a Java implementation in particular. Just to be clear, I intend on using the algorithm on Earth only and so I don't need to accommodate a variable radius. It doesn't have to be hugely accurate (+/-20% is fine) and it'll only be used to calculate bounding boxes over small distances (no more than 150km). So I'm happy to sacrifice some accuracy for an efficient algorithm. Any help is much appreciated. Edit: I should have been clearer, I really am after a square, not a circle. I understand that the distance between the center of a square and various points along the square's perimeter is not a constant value like it is with a circle. I guess what I mean is a square where if you draw a line from the center to any one of the four points on the perimeter that results in a line perpendicular to a side of the perimeter, then those 4 lines have the same length.

  Read the article

• using paypals html api is safe?

  - by ajsie

  im trying out paypals html api where you specify price, item_name, customer information and so on in the html: <form action="https://www.paypal.com/cgi-bin/webscr" method="post" id="payPalForm"> <input type="hidden" name="cmd" value="_cart" /> <input type="hidden" name="upload" value="1" /> <input type="hidden" name="no_note" value="1" /> <input type="hidden" name="business" value="[email protected]" /> <input type="hidden" name="currency_code" value="SEK" /> <input type="hidden" name="return" value="http://freelanceswitch.com/payment-complete/" /> <input type="hidden" name="tax_rate" value="25" /> <input type="hidden" name="item_name_1" value="Apple Macpro" /> <input type="hidden" name="item_number_1" value="01 - Product 1" /> <input type="hidden" name="amount_1" value="25000" /> <input type="hidden" name="item_name_2" value="Apple Macbook" /> <input type="hidden" name="item_number_2" value="02 - Product 2" /> <input type="hidden" name="amount_2" value="12500" /> <input type="hidden" name="item_name_3" value="Apple Macbook Air" /> <input type="hidden" name="item_number_3" value="03 - Product 3" /> <input type="hidden" name="amount_3" value="12500" /> <input type="submit" name="Submit" value="Submit" /> </form> when the user clicks submit it takes him/her to paypals payment page. but doesn't this mean that a hacker could change the order by manipulating the html code? i can´t figure out how paypal prevents this security problem.

  Read the article

• html - selection range - getting the range + starting node + ending node + distance

  - by sugar

  From my previous question for selecting specific html text, I have gone through this link to understand range in html string. Actually I am confused here very much. My question is as follows. For selecting a specific text on html page. We need to follow this steps. assumed html <h4 id="entry1196"><a href="http://radar.oreilly.com/archives/2007/03/call_for_a_blog_1.html" class="external">Call for a Blogger's Code of Conduct</a></h4> <p>Tim O'Reilly calls for a Blogger Code of Conduct. His proposals are:</p> <ol> <li>Take responsibility not just for your own words, but for the comments you allow on your blog.</li> <li>Label your tolerance level for abusive comments.</li> <li>Consider eliminating anonymous comments.</li> </ol> java script to make selection by range var range = document.createRange(); // create range var startPar = [the p node]; // starting parameter var endLi = [the second li node]; // ending parameter range.setStart(startPar,13); // distance from starting parameter. range.setEnd(endLi,17); // distance from ending parameter range.select(); // this statement will make selection I want to do this in invert way. I mean, assume that selection is done by user on browser (safari). My question is that How can we get starting node ( as we have 'the p node' here ) & ending node ( as we have 'the second li node' here ) and the range as well (as we have 13,17 here) ? Please help me. Thanks in advance for sharing your great knowledge. Sagar

  Read the article

• Preferred way of application initialization

  - by lisak

  Do you guys have your own little framework for project startups ? I mean, every time one needs to do the same things at the beginning: Context initialization - ideally after arguments are processed. Sometimes without interactive user input, sometimes with input reader. Sometimes we need to load properties, sometimes not. Then we need to get a class out of context and run its method. Programming....programming until writing shell script to place everything on classpath. It's true that it differs according to the actual needs. But it seems to me, that I'm doing always almost the same, again and again from the scratch. Sometimes I realize that I'm postponing my work just because I don't want to do these annoying startups. It would be great if there was some kind of universal Main class doing reflection to specified bean, context initialization, argument parsing, interactive user input reading and have the programmer do the important things...All setup might be done via spring configuration. I think I'll have to do it by myself. I'd appreciate your ideas

  Read the article

• Would it be possible to have a UTF-8-like encoding limited to 3 bytes per character?

  - by dan04

  UTF-8 requires 4 bytes to represent characters outside the BMP. That's not bad; it's no worse than UTF-16 or UTF-32. But it's not optimal (in terms of storage space). There are 13 bytes (C0-C1 and F5-FF) that are never used. And multi-byte sequences that are not used such as the ones corresponding to "overlong" encodings. If these had been available to encode characters, then more of them could have been represented by 2-byte or 3-byte sequences (of course, at the expense of making the implementation more complex). Would it be possible to represent all 1,114,112 Unicode code points by a UTF-8-like encoding with at most 3 bytes per character? If not, what is the maximum number of characters such an encoding could represent? By "UTF-8-like", I mean, at minimum: The bytes 0x00-0x7F are reserved for ASCII characters. Byte-oriented find / index functions work correctly. You can't find a false positive by starting in the middle of a character like you can in Shift-JIS.

  Read the article

• Do [sprite stopActionByTag: kTag]; working differently for different CCActions ?

  - by srikanth rongali

  //prog 1 -(void)gameLogic:(ccTime)dt { id actionMove = [CCMoveTo actionWithDuration:1.0 position:ccp(windowSize.width/2-400, actualY)]; [actionMove setTag:6]; [self schedule:@selector(update:)]; [hitBullet runAction:actionMove]; } -(void)update:(ccTime)dt { if ( (CGRectIntersectsRect(hitRect, playerRect)) ) { [[[self getActionByTag:6] retain] autorelease]; [hitBullet stopActionByTag: 6]; } } //prog 2 -(void)gameLogic:(ccTime)dt { id actionMove = [CCMoveTo actionWithDuration:1.0 position:ccp(windowSize.width/2-400, actualY)]; id hitBulletAction = [CCSequence actionWithDuration:(intervalforEnemyshoot)]; id hitBulletSeq = [CCSequence actions: hitBulletAction, actionMove, nil]; [hitBulletSeq setTag:5]; [self schedule:@selector(update:)]; [hitBullet runAction:hitBulletSeq]; } -(void)update:(ccTime)dt { if ( (CGRectIntersectsRect(hitRect, playerRect)) ) { [[[self getActionByTag:5] retain] autorelease]; [hitBullet stopActionByTag: 5]; } } While prog1 is working prog2 is not working ? I think the both are same. But why the two stopActions are working differently in two prog1 and prog2 ? I mean the actions are stopped in prog1 but the actions are not stopping in prog2 ? thank You.

  Read the article

• How do ASP.NET MVC Routes work?

  - by Pure.Krome

  Hi folks, imagine i have the following route setup... public static void RegisterRoutes(RouteCollection routes) { routes.IgnoreRoute("{resource}.axd/{*pathInfo}"); routes.MapRoute( "Default", "{controller}/{action}/{id}", new { controller = "Home", action = "Index", id = "" } ); // Added custom route here! routes.MapRoute( "CatchAll", "{*catchall}," new { controller = "Error", action = "NotFound" } ); } nothing new - that's the default ASP.NET MVC1 RegisterRoutes method, with one custom route added. Now, if I goto the following url, i get a 404... http://whatever/Home/MissingActionMethod So there's no ActionMethod called MissingActionMethod in the HomeController. So, does this mean, if i goto the 1st route defined, above .. and fail to find an action .. do I then come back and try the second route? rinse-repeat? Or once i match a route, i then try and execute that route .. and if i fail (ie, find the action is missing) .. then .. bad luck? boomski? cheers!

  Read the article

• Use of var keyword in C#

  - by kronoz

  After discussion with colleagues regarding the use of the 'var' keyword in C# 3 I wondered what people's opinions were on the appropriate uses of type inference via var? For example I rather lazily used var in questionable circumstances, e.g.:- foreach(var item in someList) { // ... } // Type of 'item' not clear. var something = someObject.SomeProperty; // Type of 'something' not clear. var something = someMethod(); // Type of 'something' not clear. More legitimate uses of var are as follows:- var l = new List<string>(); // Obvious what l will be. var s = new SomeClass(); // Obvious what s will be. Interestingly LINQ seems to be a bit of a grey area, e.g.:- var results = from r in dataContext.SomeTable select r; // Not *entirely clear* what results will be here. It's clear what results will be in that it will be a type which implements IEnumerable, however it isn't entirely obvious in the same way a var declaring a new object is. It's even worse when it comes to LINQ to objects, e.g.:- var results = from item in someList where item != 3 select item; This is no better than the equivilent foreach(var item in someList) { // ... } equivilent. There is a real concern about type safety here - for example if we were to place the results of that query into an overloaded method that accepted IEnumerable<int> and IEnumerable<double> the caller might inadvertently pass in the wrong type. Edit - var does maintain strong typing but the question is really whether it's dangerous for the type to not be immediately apparent on definition, something which is magnified when overloads mean compiler errors might not be issued when you unintentionally pass the wrong type to a method. Related Question: http://stackoverflow.com/questions/633474/c-do-you-use-var

  Read the article

• Should I use formal methods on my software project?

  - by Michael

  Our client wants us to build a web-based, rich internet application for gathering software requirements. Basically it's a web-based case tool that follows a specific process for getting requirements from stakeholders. I'm the project manager and we're still in the early phases of the project. I've been thinking about using formal methods to help clarify the requirements for the tool for both my client and the developers. By formal methods I mean some form of modeling, possibly something mathematically-based. Some of the things I've read about and are considering include Z (http://en.wikipedia.org/wiki/Z_notation), state machines, UML 2.0 (possibly with extensions such as OCL), Petri nets, and some coding-level stuff like contracts and pre and post conditions. Is there anything else I should consider? The developers are experienced but depending on the formalism used they may have to learn some math. I'm trying to determine whether it's worth while for me to use formal methods on this project and if so, to what extent. I know "it depends" so the most helpful answers for me is a yes/no and supporting arguments. Would you use formal methods if you were on this project?

  Read the article

• Enumerating a string

  - by JamesB

  I have a status which is stored as a string of a set length, either in a file or a database. I'm looking to enumerate the possible status' I have the following type to define the possible status' Type TStatus = (fsNormal = Ord('N'),fsEditedOnScreen = Ord('O'), fsMissing = Ord('M'),fsEstimated = Ord('E'),fsSuspect = Ord('s'), fsSuspectFromOnScreen = Ord('o'),fsSuspectMissing = Ord('m'), fsSuspectEstimated = Ord('e')); Firstly is this really a good idea? or should I have a seperate const array storing the char conversions? That would mean more than one place to update. Now convert a string to a status array I have the following, but how can I check if a char is valid without looping through the enumeration? Function StrToStatus(Value : String):TStatusArray; var i: Integer; begin if Trim(Value) = '' then begin SetLength(Result,0); Exit; end; SetLength(Result,Length(Value)); for i := 1 to Length(Value) do begin Result[i] := TStatus(Value[i]); // I don't think this line is safe. end; end; AFAIK this should be fine for converting back again. Function StatusToStr(Value : TStatusArray):String; var i: Integer; begin for i := 0 to Length(Value) - 1 do Result := Result + Chr(Ord(Value[i])) end; I'm using Delphi 2007

  Read the article

• What is a Windows scripting language that: does not rely on .NET and offers the most OOP support and

  - by jJack

  What is a Windows scripting language that: does not rely on .NET and offers the most OOP support and has simplest deployment? It doesn't necessarily need to be a scripting language; It can be in the form of a compiled executable, however it needs to be self contained--only ONE file, no DLL's and it cannot be declared to "include" other files. I cannot rely on the user having any .NET installed and it needs to be able to run on Windows 7 64 bit. By "most OOP support", I basically mean anything that has better OOP support than VBScript. A little context: Everything I have done thus far is in VBScript and writes a bunch of data into an .html file, which in the end is to be viewed by Internet Explorer. It also zips up a bunch of directories and files. It heavily relies on accessing the registry, file-system, and WMI (I can probably do without accessing WMI though, as long as I have good registry access). I can bring myself to code in any language so long as it meets me ridonkulous requirements stated above. I look forward to some good answers from those more experienced than I.

  Read the article

• Using a class within a class?

  - by Josh

  I built myself a MySQL class which I use in all my projects. I'm about to start a project that is heavily based on user accounts and I plan on building my own class for this aswell. The thing is, a lot of the methods in the user class will be MySQL queries and methods from the MySQL class. For example, I have a method in my user class to update someone's password: class user() { function updatePassword($usrName, $newPass) { $con = mysql_connect('db_host', 'db_user', 'db_pass'); $sql = "UPDATE users SET password = '$newPass' WHERE username = '$userName'"; $res = mysql_query($sql, $con); if($res) return true; mysql_close($con); } } (I kind of rushed this so excuse any syntax errors :) ) As you can see that would use MySQL to update a users password, but without using my MySQL class, is this correct? I see no way in which I can use my MySQL class within my users class without it seeming dirty. Do I just use it the normal way like $DB = new DB();? That would mean including my mysql.class.php somewhere too... I'm quite confused about this, so any help would be appreciated, thanks.

  Read the article

• Optimizing processing and management of large Java data arrays

  - by mikera

  I'm writing some pretty CPU-intensive, concurrent numerical code that will process large amounts of data stored in Java arrays (e.g. lots of double[100000]s). Some of the algorithms might run millions of times over several days so getting maximum steady-state performance is a high priority. In essence, each algorithm is a Java object that has an method API something like: public double[] runMyAlgorithm(double[] inputData); or alternatively a reference could be passed to the array to store the output data: public runMyAlgorithm(double[] inputData, double[] outputData); Given this requirement, I'm trying to determine the optimal strategy for allocating / managing array space. Frequently the algorithms will need large amounts of temporary storage space. They will also take large arrays as input and create large arrays as output. Among the options I am considering are: Always allocate new arrays as local variables whenever they are needed (e.g. new double[100000]). Probably the simplest approach, but will produce a lot of garbage. Pre-allocate temporary arrays and store them as final fields in the algorithm object - big downside would be that this would mean that only one thread could run the algorithm at any one time. Keep pre-allocated temporary arrays in ThreadLocal storage, so that a thread can use a fixed amount of temporary array space whenever it needs it. ThreadLocal would be required since multiple threads will be running the same algorithm simultaneously. Pass around lots of arrays as parameters (including the temporary arrays for the algorithm to use). Not good since it will make the algorithm API extremely ugly if the caller has to be responsible for providing temporary array space.... Allocate extremely large arrays (e.g. double[10000000]) but also provide the algorithm with offsets into the array so that different threads will use a different area of the array independently. Will obviously require some code to manage the offsets and allocation of the array ranges. Any thoughts on which approach would be best (and why)?

  Read the article

< Previous Page | 511 512 513 514 515 516 517 518 519 520 521 522  | Next Page >