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  • How to keep track of TextPointer in WPF RichTextBox?

    - by Alan Spark
    I'm trying to get my head around the TextPointer class in a WPF RichTextBox. I would like to be able to keep track of them so that I can associate information with areas in the text. I am currently working with a very simple example to try and figure out what is going on. In the PreviewKeyDown event I am storing the caret position and then in the PreviewKeyUp event I am creating a TextRange based on the before and after caret positions. Here is a code sample that illustrates what I am trying to do: // The caret position before typing private TextPointer caretBefore = null; private void rtbTest_PreviewKeyDown(object sender, KeyEventArgs e) { // Store caret position caretBefore = rtbTest.CaretPosition; } private void rtbTest_PreviewKeyUp(object sender, KeyEventArgs e) { // Get text between before and after caret positions TextRange tr = new TextRange(caretBefore, rtbTest.CaretPosition); MessageBox.Show(tr.Text); } The problem is that the text that I get is blank. For example, if I type the character 'a' then I would expect to find the text "a" in the TextRange. Does anyone know what is going wrong? It could be something very simple but I've spent an afternoon getting nowhere. I am trying to embrace the new WPF technology but find that the RichTextBox in particular is so complicated that it makes even doing simple things like this difficult. If anyone has any links that do a good job of explaining the TextPointer, I would appreciate it if you can let me know.

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  • Objective-C : Sorting NSMutableArray containing NSMutableArrays

    - by Dough
    Hi ! I'm currently using NSMutableArrays in my developments to store some data taken from an HTTP Servlet. Everything is fine since now I have to sort what is in my array. This is what I do : NSMutableArray *array = [[NSMutableArray arrayWithObjects:nil] retain]; [array addObject:[NSArray arrayWithObjects: "Label 1", 1, nil]]; [array addObject:[NSArray arrayWithObjects: "Label 2", 4, nil]]; [array addObject:[NSArray arrayWithObjects: "Label 3", 2, nil]]; [array addObject:[NSArray arrayWithObjects: "Label 4", 6, nil]]; [array addObject:[NSArray arrayWithObjects: "Label 5", 0, nil]]; First column contain a Label and 2nd one is a score I want the array to be sorted descending. Is the way I am storing my data a good one ? Is there a better way to do this than using NSMutableArrays in NSMutableArray ? I'm new to iPhone dev, I've seen some code about sorting but didn't feel good with that. Thanks in advance for your answers !

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  • Store comparison in variable (or execute comparison when it's given as an string)

    - by BorrajaX
    Hello everyone. I'd like to know if the super-powerful python allows to store a comparison in a variable or, if not, if it's possible calling/executing a comparison when given as an string ("==" or "!=") I want to allow the users of my program the chance of giving a comparison in an string. For instance, let's say I have a list of... "products" and the user wants to select the products whose manufacturer is "foo". He could would input something like: Product.manufacturer == "foo" and if the user wants the products whose manufacturer is not "bar" he would input Product.manufacturer != "bar" If the user inputs that line as an string, I create a tree with an structure like: != / \ manufacturer bar I'd like to allow that comparison to run properly, but I don't know how to make it happen if != is an string. The "manufacturer" field is a property, so I can properly get it from the Product class and store it (as a property) in the leaf, and well... "bar" is just an string. I'd like to know if I can something similar to what I do with "manufacturer": storing it with a 'callable" (kind of) thing: the property with the comparator: != I have tried with "eval" and it may work, but the comparisons are going to be actually used to query a MySQL database (using sqlalchemy) and I'm a bit concerned about the security of that... Any idea will be deeply appreciated. Thank you! PS: The idea of all this is being able to generate a sqlalchemy query, so if the user inputs the string: Product.manufacturer != "foo" || Product.manufacturer != "bar" ... my tree thing can generate the following: sqlalchemy.or_(Product.manufacturer !="foo", Product.manufacturer !="bar") Since sqlalchemy.or_ is callable, I can also store it in one of the leaves... I only see a problem with the "!="

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  • NHibernate query with Projections.Cast to DateTime

    - by stiank81
    I'm experimenting with using a string for storing different kind of data types in a database. When I do queries I need to cast the strings to the right type in the query itself. I'm using .Net with NHibernate, and was glad to learn that there exists functionality for this. Consider the simple class: public class Foo { public string Text { get; set; } } I successfully use Projections.Cast to cast to numeric values, e.g. the following query correctly returns all Foos with an interger stored as int - between 1-10. var result = Session.CreateCriteria<Foo>() .Add(Restrictions.Between(Projections.Cast(NHibernateUtil.Int32, Projections.Property("Text")), 1, 10)) .List<Foo>(); Now if I try using this for DateTime I'm not able to make it work no matter what I try. Why?! var date = new DateTime(2010, 5, 21, 11, 30, 00); AddFooToDb(new Foo { Text = date.ToString() } ); // Will add it to the database... var result = Session .CreateCriteria<Foo>() .Add(Restrictions.Eq(Projections.Cast(NHibernateUtil.DateTime, Projections.Property("Text")), date)) .List<Foo>();

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  • Display a Photo Gallery using Asp.Net and SQL

    - by sweetcoder
    I have recently added photos to my SQL database and have displayed them on an *.aspx page using Asp:Image. The ImageUrl for this control stored in a separate *.aspx page. It works great for profile pictures. I have a new issue at hand. I need each user to be able to have their own photo gallery page. I want the photos to be stored in the sql database. Storing the photos is not difficult. The issue is displaying the photos. I want the photos to be stored in a thumbnail grid fashion, when the user clicks on the photo, it should bring up the photo on a separate page. What is the best way to do this. Obviously it is not to use Asp:Image. I am curious if I should use a Gridview. If so, how do I do that and should their be a thumbnail size stored in the database for this? Once the picture is click on how does the other page look so that it displays the correct image. I would think it is not correct to send the photoId through the url. Below is code from the page I use to display profile pictures. protected void Page_Load(object sender, EventArgs e) { string sql = "SELECT [ProfileImage] FROM [UserProfile] WHERE [UserId] = '" + User.Identity.Name.ToString() + "'"; string strCon = System.Web.Configuration.WebConfigurationManager.ConnectionStrings["SocialSiteConnectionString"].ConnectionString; SqlConnection conn = new SqlConnection(strCon); SqlCommand comm = new SqlCommand(sql, conn); conn.Open(); Response.ContentType = "image/jpeg"; Response.BinaryWrite((byte[])comm.ExecuteScalar()); conn.Close(); }

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  • Legit? Two foreign keys referencing the same primary key.

    - by Ryan
    Hi All, I'm a web developer and have recently started a project with a company. Currently, I'm working with their DBA on getting the schema laid out for the site, and we've come to a disagreement regarding the design on a couple tables, and I'd like some opinions on the matter. Basically, we are working on a site that will implement a "friends" network. All users of the site will be contained in a table tblUsers with (PersonID int identity PK, etc). What I am wanting to do is to create a second table, tblNetwork, that will hold all of the relationships between users, with (NetworkID int identity PK, Owners_PersonID int FK, Friends_PersonID int FK, etc). Or conversely, remove the NetworkID, and have both the Owners_PersonID and Friends_PersonID shared as the Primary key. This is where the DBA has his problem. Saying that "he would only implement this kind of architecture in a data warehousing schema, and not for a website, and this is just another example of web developers trying to take the easy way out." Now obviously, his remark was a bit inflammatory, and that have helped motivate me to find an suitable answer, but more so, I'd just like to know how to do it right. I've been developing databases and programming for over 10 years, have worked with some top-notch minds, and have never heard this kind of argument. What the DBA is wanting to do is instead of storing both the Owners_PersonId and Friends_PersonId in the same table, is to create a third table tblFriends to store the Friends_PersonId, and have the tblNetwork have (NetworkID int identity PK, Owner_PersonID int FK, FriendsID int FK(from TBLFriends)). All that tblFriends would house would be (FriendsID int identity PK, Friends_PersonID(related back to Persons)). To me, creating the third table is just excessive in nature, and does nothing but create an alias for the Friends_PersonID, and cause me to have to add (what I view as unneeded) joins to all my queries, not to mention the extra cycles that will be necessary to perform the join on every query. Thanks for reading, appreciate comments. Ryan

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  • flushing database cache in SWI-Prolog

    - by JPro
    We are using swi-prolog to run our testcases. Whenever the test starts, I am opening the connection to MYSQL database and storing the Name of the Test hat is being done and then closing the DB. These tests run for about 2 days continuously. After the tests are done, the results basically gets stored in folder in the server. There is a predicate in another prolog file that is called to update the results to the MYSQL database. The code is simple, I use odbc library and just call odbc_* predicates to connect and update the mysql by issuing direct queries. The actual problem is : If I try to call the Predicate from the same Prolog window, where the test just got completed, I get an error as updating to the DB server. Although I do not get any error in the connection. If I close the session of that prolog with halt and closing all the open prolog windows , then open an other complete new instance of Prolog and run the predicate the update goes well. I have a feeling that there is some connection reference to the MySQL DB in Prolog database. Is there any way to clear the database in prolog so that I can run the same predicate without closing any existing prolog windows? Any ideas appreciated. Thanks.

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  • trying to get the most accurate device location from GPS or Network in Android

    - by arc
    I am trying to determine the most accurate location of a device, in the shortest time possible. I am storing the data as a geopoint, and have it displayed on a mapview. The last time I activated the GPS on my device and let it get a location lock, i was approx 80 miles from where I am now. I have a location manager setup and a location listener. If I do this, I get NULL. myLocOverlay = new MyLocationOverlay(this, mapView); GeoPoint test = myLocOverlay.getMyLocation(); but in the next couple of lines; myLocOverlay.enableMyLocation(); mapView.getOverlays().add(myLocOverlay); With this, the overlay on the map shows the current location. It is using the Network provider, but is also attempting to get a GPS fix (it can't as I am indoors and no where near the top floor). If I construct the geopoint like this; if(lm.getLastKnownLocation("gps") != null) { test = new GeoPoint( (int) (lm.getLastKnownLocation("gps").getLatitude() * 1E6), (int) (lm.getLastKnownLocation("gps").getLongitude() * 1E6)); } else { if(lm.getLastKnownLocation("network") != null) { test = new GeoPoint( (int) (lm.getLastKnownLocation("network").getLatitude() * 1E6), (int) (lm.getLastKnownLocation("network").getLongitude() * 1E6)); } //bad things } Then I get confusing results. If I disable the devices GPS provider then the code moves onto the Network Provider and gives me a fairly accurate result. If I enable the GPS provider, then the geopoint comes back as the last place I allowed the device to get a GPS lock. I want to avoid the above results, and so was looking at using; GeoPoint test = myLocOverlay.getMyLocation(); BUT as I said above, I just get NULL from that. Short of getting the geopoints from both GPS and Network and then comparing them, and disregarding the GPS result if it is say 1 mile out of the Network location - i'm a bit stuck. why doesn't getMyLocation() work, shouldnt that return the GeoPoint of what myLocOverlay is showing on the mapview?

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  • The Date type and the Android database

    - by cdonner
    I understand that SQLite stores dates as long integers. When I read rows into a cursor using the standard method (i.e. using the query() method that reads data into a cursor), the result is a date string that includes the time. If I want a different format, I have to parse the string back into a date - possible, but a bit backwards. By using a ViewBinder (as suggested in this question), I can pretty much do anything I want, but the date is already a string at the time the method executes. The accepted answer to the above question also suggests that storing dates as longs would help avoid this problem. I don't want to do that, just in case I want to interpret my data with something else than this application. Maybe I want to expose it via a provider. Is there a way to handle this in the database adapter instead, i.e. controlling the date format that the cursor contains, so that I don't have to change the schema, and don't have to parse the default output back into a Date type?

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  • UML class diagram vs ER database diagram

    - by salva84
    Hi, I'm a little confused, I'm developing a program, the program consist in two parts, the server and the clients, there are groups, places, messages... stored in the server, and the clients has to connect with it. I've design the use cases diagram, the activity diagrams, and I have design the class diagram too. The thing is that I want to implement the server in a mysql tables for storing the users, groups, places... users in groups... so I've designed a E-R diagram consisting in 6 tables, but the problem is that I think that my class diagram and my ER diagram looks too similar, I mean, I think I'm not doing things right because I have a class for each table practically, and when I have to extract all the users on my system, do I have to convert all the rows into objects at first and write in the database for each object modified? The easy choice for me would be to base my whole application only in the database, and making a class to extract and insert data in it, but I have to follow the UML specification and I'm a little confused what to do with the class diagram, because the books I have read say that I have to create a class for each "entity" of my program. Sorry for my bad English. Thank you.

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  • Obtaining MAC address

    - by rink.attendant.6
    According to Obtain client MAC address in ASP.NET Application, it is not possible. I am not entirely convinced because whenever I connect to Tim Hortons WiFi, my MAC address is known. Occasionally, the network is slow and I see this URL like this before being redirected to the Connect page: http://timhortonswifi.com/cp/tdl3/index.asp ?cmd=login &switchip=172.30.129.73 &mac=60:6c:66:17:1a:83 &ip=10.40.66.229 &essid=Tim%20Hortons%20WiFi &apname=TDL-ON-NEP-02177-WAP1 &apgroup=02177 &url=http%3A%2F%2Fweather%2Egc%2Eca%2Fcity%2Fpages%2Fon-72_metric_e%2Ehtml So according to this URL, the site knows the IP address of the router, my MAC address, the IP address assigned to my device by the router, the network SSID, some other pieces of information, and the URL I was trying to access prior to connecting. There's two options: Tim Hortons WiFi Basic and Tim Hortons WiFi Plus, where the "Plus" option allows me to connect to any Tim Hortons WiFi access point in Canada automatically with this device. Registration requires an email address, so I'm assuming this is possible by checking the MAC address and storing it in a database that routers ping upon connection. More info here. According to the extension of this page, I can safely assume it is ASP. How are they obtaining this information?

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  • WMD markdown editor - HTML to Markdown conversion

    - by gg1
    I am using wmd markdown editor on a project and had a question: When I post the form containing the markdown text area, it (as expected) posts html to the server. However, say upon server-side validation something fails and I need to send the user back to edit their entry, is there anyway to refill the textarea with just the markdown and not the html? Since as I have it set up, the server only has access to the post data (which is in the form of html) so I can't seem to think of a way to do this. Any ideas? Preferably a non-javascript based solution. Update: I found an html to markdown converter called markdownify. I guess this might be the best solution for displaying the markdown back to the user...any better alternatives are welcome! Update 2: I found this post on SO and I guess there is an option to send the data to the server as markdown instead of html. Are there any downsides to simply storing the data as markdown in the database? What about displaying it back to the user (outside of an editor)? Maybe it would be best to post both versions (html AND markdown) to the server... SOLVED: I can simply use php markdown to convert the markdown to html serverside.

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  • Firefox -- Dynamically embedding <svg> element in SVG

    - by zourtney
    I am trying dynamically to append an <svg> element within an existing SVG island on an XHTML page (Firefox 3.6.3). Done manually, this works as expected: <svg xmlns="http://www.w3.org/2000/svg"> <svg xmlns="http://www.w3.org/2000/svg"> ... </svg> </svg> However, if you dynamically add this element using JavaScript, the browser crashes. Simple example: <html xmlns="http://www.w3.org/1999/xhtml" xmlns:svg="http://www.w3.org/2000/svg"> <head> <title>SVG island example</title> <script type="text/javascript"><![CDATA[ function crash( ) { svgs = document.getElementsByTagNameNS( "http://www.w3.org/2000/svg", "svg" ); for ( var i = 0; i < svgs.length; i++ ) { var e = document.createElementNS( "http://www.w3.org/2000/svg", "svg" ); svgs[i].appendChild( e ); } } ]]></script> </head> <body> <svg id="mySVG" xmlns="http://www.w3.org/2000/svg"> </svg> <button onclick="crash()">Crash Firefox</button> </body> </html> Interestingly, if I do a getElementById, it works fine. Interesting, but not particularly helpful in my situation since I'm storing pointers to SVGDocuments. Example: function doesntCrash( ) { var svg = document.getElementById( "mySVG" ); var e = document.createElementNS( "http://www.w3.org/2000/svg", "svg" ); svg.appendChild( e ); } As far as I can tell, this is a Firefox bug. Does anyone have any insight into this matter?

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  • Why are floating point values so prolific?

    - by Kibbee
    So, title says it all. Why are floating point values so prolific in computer programming. Due to problems like rounding errors, and not being able to even accurately represent numbers such as 0.1, I really can't see how they got as far as they did. I understand that the computation is faster with floating point numbers, however, I can think of only a few cases that they actually the right data type would be using. If you sat back and think about every time you used a floating point value, how many times did you say, well, some error would be ok, as long as the result was a few microseconds faster. It really makes me think because Jeff was talking about NP completeness, and how heuristics give an answer that is kind of right. And well, computers shouldn't do that. They should give you the answer that is correct. Yet we see floating point values used in many applications where they are completely not valid. What really bugs me, isn't that floating point exists, but that in many languages, there isn't even a viable alternative, non-floating point, decimal value. A lot of programmers when doing financial applications have to fall back to storing the number of cents in an integer field. Which brings with it all kinds of other problems. Why do floats continue to be so prolific, even though they can't represent the real answer, and we expect computers to be accurate? [EDIT] Just to clarify, I was talking about Base 2 floating points, and not base 10 floating points. .Net offers the Decimal data type, which is a base 10 floating point value which offers a much better representation of the numbers we deal with on a daily basis in most computer programs. I find it hard to believe that even modern languages like Java don't support base 10 floating point values, unless you want to move into the realm of things like BigDecimal, which isn't really the right answer either in a lot of situations.

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  • Nested Routes and Parameters for Rails URLs (Best Practice)

    - by viatropos
    Hey there, I have a decent understanding of RESTful urls and all the theory behind not nesting urls, but I'm still not quite sure how this looks in an enterprise application, like something like Amazon, StackOverflow, or Google... Google has urls like this: http://code.google.com/apis/ajax/ http://code.google.com/apis/maps/documentation/staticmaps/ https://www.google.com/calendar/render?tab=mc Amazon like this: http://www.amazon.com/books-used-books-textbooks/b/ref=sa_menu_bo0?ie=UTF8&node=283155&pf_rd_p=328655101&pf_rd_s=left-nav-1&pf_rd_t=101&pf_rd_i=507846&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=1PK4ZKN4YWJJ9B86ANC9 http://www.amazon.com/Ruby-Programming-Language-David-Flanagan/dp/0596516177/ref=sr_1_1?ie=UTF8&s=books&qid=1258755625&sr=1-1 And StackOverflow like this: http://stackoverflow.com/users/169992/viatropos http://stackoverflow.com/questions/tagged/html http://stackoverflow.com/questions/tagged?tagnames=html&sort=newest&pagesize=15 So my question is, what is best practice in terms of creating urls for systems like these? When do you start storing parameters in the url, when don't you? These big companies don't seem to be following the rules so hotly debated in the ruby community (that you should almost never nest URLs for example), so I'm wondering how you go about implementing your own urls in larger scale projects because it seems like the idea of not nesting urls breaks down at anything larger than a blog. Any tips?

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  • Any way for a class to prevent outside code from declaring variables of its type?

    - by supercat
    Is it possible for a class of exposing a type for function returns, without allowing users of that class to create variables of that type? A couple usage scenarios: A Fluent interface on a large class; a statement like "foo=bar.WithX(5).WithY(9).WithZ(19);" would be inefficient if it had to create three new instances of the class, but could be much more efficient if the WithX could create one instance, and the other statements could simply use it. A class may wish to support a statement like "foo[19].x = 9;" even when foo itself isn't an array, and does not hold the data in class instances that can be exposed to the public; one way to do that is to have foo[19] return a struct which holds a reference to 'foo' and the value '19', and has a member property 'x' which could call "foo.SetXValue(19, 9);" Such a struct could have a conversion operator to convert itself to the "apparent" type of foo[19]. In both of these scenarios, storing the value returned by a method or property into a variable and then using it more than once would cause strange behavior. It would be desirable if the designer of the class exposing such methods or properties could ensure that callers wouldn't be able to use them more than once. Is there any practical way to accomplish that?

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  • adjacency list creation , out of Memory error

    - by p1
    Hello , I am trying to create an adjacency list to store a graph.The implementation works fine while storing 100,000 records. However,when I tried to store around 1million records I ran into OutofMemory Error : Exception in thread "main" java.lang.OutOfMemoryError: Java heap space at java.util.Arrays.copyOfRange(Arrays.java:3209) at java.lang.String.(String.java:215) at java.io.BufferedReader.readLine(BufferedReader.java:331) at java.io.BufferedReader.readLine(BufferedReader.java:362) at liarliar.main(liarliar.java:39) Following is my implementation HashMap<String,ArrayList<String>> adj = new HashMap<String,ArrayList<String>>(num); while ((str = in.readLine()) != null) { StringTokenizer Tok = new StringTokenizer(str); name = (String) Tok.nextElement(); cnt = Integer.valueOf(Tok.nextToken()); ArrayList<String> templist = new ArrayList<String>(cnt); while(cnt>0) { templist.add(in.readLine()); cnt--; } adj.put(name,templist); } //done creating a adjacency list I am wondering, if there is any better way to implement the adjacency list. Also, I know number of nodes right in the begining and , in the future I flatten the list as I visit nodes. Any suggestions ? Thanks

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  • Get most left|right|top|bottom point contained in box

    - by skyman
    I'm storing Points Of Interest (POI) in PostgreSQL database, and retrieve them via PHP script to Android application. To reduce internet usage I want my mobile app to know if there are any points in the neighborhood of currently displayed area. My idea is to store bounds of the rectangle containing all points already retrieved (in other words: nearest point on the left (West) of most west already retrieved, nearest point above (North) of most north already retrieved etc.) and I will make next query when any edge of screen goes outside of this bounds. Currently I can retrieve points which are in "single screen" (in the area covered by currently displayed map) using: SELECT * FROM ch WHERE loc <@ (box '((".-$latSpan.", ".$lonSpan."),(".$latSpan.", ".-$lonSpan."))' + point '".$loc."') Now I need to know four most remote points in each direction, than I will be able to retrieve next four "more remote" points. Is there any possibility to get those points (or box) directly from PostgreSQL (maybe using some "aggregate points to box" function)?

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  • Attempting to find a formula for tessellating rectangles onto a board, where middle square can't be

    - by timemirror
    I'm working on a spatial stacking problem... at the moment I'm trying to solve in 2D but will eventually have to make this work in 3D. I divide up space into n x n squares around a central block, therefore n is always odd... and I'm trying to find the number of locations that a rectangle of any dimension less than n x n (eg 1x1, 1x2, 2x2 etc) can be placed, where the middle square is not available. So far I've got this.. total number of rectangles = ((n^2 + n)^2 ) / 4 ..also the total number of squares = (n (n+1) (2n+1)) / 6 However I'm stuck in working out a formula to find how many of those locations are impossible as the middle square would be occupied. So for example: [] [] [] [] [x] [] [] [] [] 3 x 3 board... with 8 possible locations for storing stuff as mid square is in use. I can use 1x1 shapes, 1x2 shapes, 2x1, 3x1, etc... Formula gives me the number of rectangles as: (9+3)^2 / 4 = 144/4 = 36 stacking locations However as the middle square is unoccupiable these can not all be realized. By hand I can see that these are impossible options: 1x1 shapes = 1 impossible (mid square) 2x1 shapes = 4 impossible (anything which uses mid square) 3x1 = 2 impossible 2x2 = 4 impossible etc Total impossible combinations = 16 Therefore the solution I'm after is 36-16 = 20 possible rectangular stacking locations on a 3x3 board. I've coded this in C# to solve it through trial and error, but I'm really after a formula as I want to solve for massive values of n, and also to eventually make this 3D. Can anyone point me to any formulas for these kind of spatial / tessellation problem? Also any idea on how to take the total rectangle formula into 3D very welcome! Thanks!

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  • Worse is better. Is there an example?

    - by J.F. Sebastian
    Is there a widely-used algorithm that has time complexity worse than that of another known algorithm but it is a better choice in all practical situations (worse complexity but better otherwise)? An acceptable answer might be in a form: There are algorithms A and B that have O(N**2) and O(N) time complexity correspondingly, but B has such a big constant that it has no advantages over A for inputs less then a number of atoms in the Universe. Examples highlights from the answers: Simplex algorithm -- worst-case is exponential time -- vs. known polynomial-time algorithms for convex optimization problems. A naive median of medians algorithm -- worst-case O(N**2) vs. known O(N) algorithm. Backtracking regex engines -- worst-case exponential vs. O(N) Thompson NFA -based engines. All these examples exploit worst-case vs. average scenarios. Are there examples that do not rely on the difference between the worst case vs. average case scenario? Related: The Rise of ``Worse is Better''. (For the purpose of this question the "Worse is Better" phrase is used in a narrower (namely -- algorithmic time-complexity) sense than in the article) Python's Design Philosophy: The ABC group strived for perfection. For example, they used tree-based data structure algorithms that were proven to be optimal for asymptotically large collections (but were not so great for small collections). This example would be the answer if there were no computers capable of storing these large collections (in other words large is not large enough in this case). Coppersmith–Winograd algorithm for square matrix multiplication is a good example (it is the fastest (2008) but it is inferior to worse algorithms). Any others? From the wikipedia article: "It is not used in practice because it only provides an advantage for matrices so large that they cannot be processed by modern hardware (Robinson 2005)."

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  • Session variables with Cucumber Stories

    - by Matthew Savage
    I am working on some Cucumber stories for a 'sign up' application which has a number of steps. Rather then writing a Huuuuuuuge story to cover all the steps at once, which would be bad, I'd rather work through each action in the controller like a regular user. My problem here is that I am storing the account ID which is created in the first step as a session variable, so when step 2, step 3 etc are visited the existing registration data is loaded. I'm aware of being able to access controller.session[..] within RSpec specifications however when I try to do this in Cucumber stories it fails with the following error (and, I've also read somewhere this is an anti-pattern etc...): Using controller.session[:whatever] or session[:whatever] You have a nil object when you didn't expect it! The error occurred while evaluating nil.session (NoMethodError) Using session(:whatever) wrong number of arguments (1 for 0) (ArgumentError) So, it seems accession the session store isn't really possible. What I'm wondering is if it might be possible to (and I guess which would be best..): Mock out the session store etc Have a method within the controller and stub that out (e.g. get_registration which assigns an instance variable...) I've looked through the RSpec book (well, skimmed) and had a look through WebRat etc, but I haven't really found an answer to my problem... To clarify a bit more, the signup process is more like a state machine - e.g. the user progresses through four steps before the registration is complete - hence 'logging in' isn't really an option (it breaks the model of how the site works)... In my spec for the controller I was able to stub out the call to the method which loads the model based on the session var - but I'm not sure if the 'antipattern' line also applies to stubs as well as mocks? Thanks!

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  • creating objects in list

    - by prince23
    List myList = new List { new Users{ Name="Kumar", Gender="M", Age=75, Parent="All"}, new Users{ Name="Suresh",Gender="M", Age=50, Parent="Kumar"}, new Users{ Name="Bennette", Gender="F",Age=45, Parent="Kumar"}, new Users{ Name="kian", Gender="M",Age=20, Parent="Suresh"}, new Users{ Name="Nathani", Gender="M",Age=15, Parent="Suresh"}, new Users{ Name="Peter", Gender="M",Age=90, Parent="All"}, new Users{ Name="Mica", Age=56, Gender="M",Parent="Peter"}, new Users{ Name="Linderman", Gender="M",Age=51, Parent="Peter"}, new Users{ Name="john", Age=25, Gender="M",Parent="Mica"}, new Users{ Name="tom", Gender="M",Age=21, Parent="Mica"}, new Users{ Name="Ando", Age=64, Gender="M",Parent="All"}, new Users{ Name="Maya", Age=24, Gender="M",Parent="Ando"}, new Users{ Name="Niki Sanders", Gender="F",Age=2, Parent="Maya"}, new Users{ Name="Angela Patrelli", Gender="F",Age=3, Parent="Maya"}, }; now i need to format the data like here i need to check the parent based on the parent i will be creating objects under the parent objects now { Name="Kumar", Gender="M", Age=75, Parent="All" } this is the top level as a property Parent ="all" now under parent object kumar here we again create a new object to store these information under object(kumar who is the parent) new Users{ Name="Suresh",Gender="M", Age=50, Parent="Kumar"}, new Users{ Name="Bennette", Gender="F",Age=45, Parent="Kumar"}, what i need to do here is i need to check the parent based on the parent create further objects under it ex: i need to achive like this. looking for the syntax how i can do it. public class SampleProjectData { public static ObservableCollection<Product> GetSampleData() { DateTime dtS = DateTime.Now; ObservableCollection<Product> teams = new ObservableCollection<Product>(); teams.Add(new Product() { PDName = "Product1", OverallStartTime = dtS, OverallEndTime = dtS + TimeSpan.FromDays(3), }); Project emp = new Project() { PName = "Project1", OverallStartTime = dtS + TimeSpan.FromDays(1), OverallEndTime = dtS + TimeSpan.FromDays(6) }; emp.Tasks.Add(new Task() { StartTime = dtS, EndTime = dtS + TimeSpan.FromDays(2), TaskName = "John's Task 3" }); emp.Tasks.Add(new Task() { StartTime = dtS + TimeSpan.FromDays(3), EndTime = dtS + TimeSpan.FromDays(4), TaskName = "John's Task 2" }); teams[0].Projects.Add(emp); emp = new Project() { PName = "Project2", OverallStartTime = dtS + TimeSpan.FromDays(1.5), OverallEndTime = dtS + TimeSpan.FromDays(5.5) }; emp.Tasks.Add(new Task() { StartTime = dtS + TimeSpan.FromDays(1), EndTime = dtS + TimeSpan.FromDays(4), TaskName = "Victor's Task" }); teams[0].Projects.Add(emp); emp = new Project() { PName = "Project3", OverallStartTime = dtS + TimeSpan.FromDays(2), OverallEndTime = dtS + TimeSpan.FromDays(5) }; emp.Tasks.Add(new Task() { StartTime = dtS + TimeSpan.FromDays(1), EndTime = dtS + TimeSpan.FromDays(4), TaskName = "Jason's Task 1" }); emp.Tasks.Add(new Task() { StartTime = dtS + TimeSpan.FromDays(7), EndTime = dtS + TimeSpan.FromDays(9), TaskName = "Jason's Task 2" }); teams[0].Projects.Add(emp); teams.Add(new Product() { PDName = "Product2", OverallStartTime = dtS, OverallEndTime = dtS + TimeSpan.FromDays(3) }); emp = new Project() { PName = "Project4", OverallStartTime = dtS + TimeSpan.FromDays(0.5), OverallEndTime = dtS + TimeSpan.FromDays(3.5) }; emp.Tasks.Add(new Task() { StartTime = dtS + TimeSpan.FromDays(1.5), EndTime = dtS + TimeSpan.FromDays(4), TaskName = "Vicky's Task" }); teams[1].Projects.Add(emp); emp = new Project() { PName = "Project5", OverallStartTime = dtS + TimeSpan.FromDays(2), OverallEndTime = dtS + TimeSpan.FromDays(6) }; emp.Tasks.Add(new Task() { StartTime = dtS + TimeSpan.FromDays(2.2), EndTime = dtS + TimeSpan.FromDays(3.8), TaskName = "Oleg's Task 1" }); emp.Tasks.Add(new Task() { StartTime = dtS + TimeSpan.FromDays(5), EndTime = dtS + TimeSpan.FromDays(6), TaskName = "Oleg's Task 2" }); emp.Tasks.Add(new Task() { StartTime = dtS + TimeSpan.FromDays(8), EndTime = dtS + TimeSpan.FromDays(9.6), TaskName = "Oleg's Task 3" }); teams[1].Projects.Add(emp); emp = new Project() { PName = "Project6", OverallStartTime = dtS + TimeSpan.FromDays(2.5), OverallEndTime = dtS + TimeSpan.FromDays(4.5) }; emp.Tasks.Add(new Task() { StartTime = dtS + TimeSpan.FromDays(0.8), EndTime = dtS + TimeSpan.FromDays(2), TaskName = "Kim's Task" }); teams[1].Projects.Add(emp); teams.Add(new Product() { PDName = "Product3", OverallStartTime = dtS, OverallEndTime = dtS + TimeSpan.FromDays(3) }); emp = new Project() { PName = "Project7", OverallStartTime = dtS + TimeSpan.FromDays(5), OverallEndTime = dtS + TimeSpan.FromDays(7.5) }; emp.Tasks.Add(new Task() { StartTime = dtS + TimeSpan.FromDays(1.5), EndTime = dtS + TimeSpan.FromDays(4), TaskName = "Balaji's Task 1" }); emp.Tasks.Add(new Task() { StartTime = dtS + TimeSpan.FromDays(5), EndTime = dtS + TimeSpan.FromDays(8), TaskName = "Balaji's Task 2" }); teams[2].Projects.Add(emp); emp = new Project() { PName = "Project8", OverallStartTime = dtS + TimeSpan.FromDays(3), OverallEndTime = dtS + TimeSpan.FromDays(6.3) }; emp.Tasks.Add(new Task() { StartTime = dtS + TimeSpan.FromDays(1.75), EndTime = dtS + TimeSpan.FromDays(2.25), TaskName = "Li's Task" }); teams[2].Projects.Add(emp); emp = new Project() { PName = "Project9", OverallStartTime = dtS + TimeSpan.FromDays(2), OverallEndTime = dtS + TimeSpan.FromDays(6) }; emp.Tasks.Add(new Task() { StartTime = dtS + TimeSpan.FromDays(2), EndTime = dtS + TimeSpan.FromDays(3), TaskName = "Stacy's Task" }); teams[2].Projects.Add(emp); return teams; } } above is an sample data where i am grouping them with static data in the same way i need **to for teh data which is cmg from DB and i need to store them list** all these three data are comig from different services. and i am storing them in a list now i have three tables data Product , Project, Task. all the data are coming from webservies. i have created three list where i am storing the data in list. List<Project>objpro= new List<Project>(); List<Product>objproduct= new List<Product>(); LIst<Task>objTask= new List<Task>(); **now what i need to do is i need to do the mapping between these tables. if you see above. i have object of Product under Product i have added object of Project and then under project object i have added task object.** now from the above data which is stored in the list i need to do the same mapping between class. and group the data. public class Product : INotifyPropertyChanged { public Product() { this.Projects = new ObservableCollection<Project>(); } public string PDName { get; set; } public ObservableCollection<Project> Projects { get; set; } private DateTime _st; public DateTime OverallStartTime { get { return _st; } set { if (this._st != value) { TimeSpan dur = this._et - this._st; this._st = value; this.OnPropertyChanged("OverallStartTime"); this.OverallEndTime = value + dur; } } } private DateTime _et; public DateTime OverallEndTime { get { return _et; } set { if (this._et != value) { this._et = value; this.OnPropertyChanged("OverallEndTime"); } } } #region INotifyPropertyChanged Members protected void OnPropertyChanged(string name) { if (this.PropertyChanged != null) this.PropertyChanged(this, new PropertyChangedEventArgs(name)); } public event PropertyChangedEventHandler PropertyChanged; #endregion } public class Project : INotifyPropertyChanged { public Project() { this.Tasks = new ObservableCollection<Task>(); } public string PName { get; set; } public ObservableCollection<Task> Tasks { get; set; } DateTime _st; public DateTime OverallStartTime { get { return _st; } set { if (this._st != value) { TimeSpan dur = this._et - this._st; this._st = value; this.OnPropertyChanged("OverallStartTime"); this.OverallEndTime = value + dur; } } } DateTime _et; public DateTime OverallEndTime { get { return _et; } set { if (this._et != value) { this._et = value; this.OnPropertyChanged("OverallEndTime"); } } } #region INotifyPropertyChanged Members protected void OnPropertyChanged(string name) { if (this.PropertyChanged != null) this.PropertyChanged(this, new PropertyChangedEventArgs(name)); } public event PropertyChangedEventHandler PropertyChanged; #endregion } public class Task : INotifyPropertyChanged { public string TaskName { get; set; } DateTime _st; public DateTime StartTime { get { return _st; } set { if (this._st != value) { TimeSpan dur = this._et - this._st; this._st = value; this.OnPropertyChanged("StartTime"); this.EndTime = value + dur; } } } private DateTime _et; public DateTime EndTime { get { return _et; } set { if (this._et != value) { this._et = value; this.OnPropertyChanged("EndTime"); } } } #region INotifyPropertyChanged Members protected void OnPropertyChanged(string name) { if (this.PropertyChanged != null) this.PropertyChanged(this, new PropertyChangedEventArgs(name)); } public event PropertyChangedEventHandler PropertyChanged; #endregion } hope my question is clear

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  • Is there an "embedded DBMS" to support multiple writer applications (processes) on the same db files

    - by Amir Moghimi
    I need to know if there is any embedded DBMS (preferably in Java and not necessarily relational) which supports multiple writer applications (processes) on the same set of db files. BerkeleyDB supports multiple readers but just one writer. I need multiple writers and multiple readers. UPDATE: It is not a multiple connection issue. I mean I do not need multiple connections to a running DBMS application (process) to write data. I need multiple DBMS applications (processes) to commit on the same storage files. HSQLDB, H2, JavaDB (Derby) and MongoDB do not support this feature. I think that there may be some File System limitations that prohibit this. If so, is there a File System that allows multiple writers on a single file? Use Case: The use case is a high-throughput clustered system that intends to store its high-volume business log entries into a SAN storage. Storing business logs in separate files for each server does not fit because query and indexing capabilities are needed on the whole biz logs. Because "a SAN typically is its own network of storage devices that are generally not accessible through the regular network by regular devices", I want to use SAN network bandwidth for logging while cluster LAN bandwidth is being used for other server to server and client to server communications.

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  • Secure hash and salt for PHP passwords

    - by luiscubal
    It is currently said that MD5 is partially unsafe. Taking this into consideration, I'd like to know which mechanism to use for password protection. Is “double hashing” a password less secure than just hashing it once? Suggests that hashing multiple times may be a good idea. How to implement password protection for individual files? Suggests using salt. I'm using PHP. I want a safe and fast password encryption system. Hashing a password a million times may be safer, but also slower. How to achieve a good balance between speed and safety? Also, I'd prefer the result to have a constant number of characters. The hashing mechanism must be available in PHP It must be safe It can use salt (in this case, are all salts equally good? Is there any way to generate good salts?) Also, should I store two fields in the database(one using MD5 and another one using SHA, for example)? Would it make it safer or unsafer? In case I wasn't clear enough, I want to know which hashing function(s) to use and how to pick a good salt in order to have a safe and fast password protection mechanism. EDIT: The website shouldn't contain anything too sensitive, but still I want it to be secure. EDIT2: Thank you all for your replies, I'm using hash("sha256",$salt.":".$password.":".$id) Questions that didn't help: What's the difference between SHA and MD5 in PHP Simple Password Encryption Secure methods of storing keys, passwords for asp.net How would you implement salted passwords in Tomcat 5.5

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  • Spell checker software

    - by Naren
    Hello Guys, I have been assigned a task to find a decent spell checker (UK English) preferably the free one for a project that we are doing. I have looked at Google AJAX API for this. The project contains some young person's (kids less than 18 years old) data which shouldn't allow exposing or storing outside the application boundaries. Google logs the data for research purpose that means Google owns the data whatever we send over the wire through Google API. Is this right? I fired an email to Google regarding the privacy of data and storage but they haven't come back. If you have some knowledge regarding this please share with me. At this point our servers might not have access to external entities that means we might not be able to use Web API for this over the wire. But it may change in the future. That means I have to find out some spell checker alternatives that can sit in our environment and do the job or an external APIs. Would you mind share your findings and knowledge in this regard. I would prefer free services but never know if you have some cracking spell checker for a few quid’s then I don't mind recommending to the project board. Technology using ASP.NET 3.5/4.0, MVC, jQuery, SQL Sever 2008 etc Cheers, Naren

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