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  • Populate datagrid using Datacontext in C# WPF

    - by anon
    I'm trying to get data from file. The file first has three lines of text that describes the file, then there is a header for the data below. I've managed to extract that. What I'm having problems is getting the data below the header line. The data below the header line can look like "1 2 3 4 5 6 7 8 9 abc". DataGrid dataGrid1 = new DataGrid(); masterGrid.Children.Add(dataGrid1); using (TextReader tr = new StreamReader(@filename)) { int lineCount = 1; while (tr.Peek() >= 0) { string line = tr.ReadLine(); { string[] data = line.Trim().Split(' '); Dictionary<string, object> sensorData = new Dictionary<string, object>(); for (int i = 0, j = 0; i < data.Length; i++) { //I know that I'm delimiting the data by a space before. //but the data from the text file doesn't necessarily have //just one space between each piece of data //so if I don't do this, spaces will become part of the data. if (String.Compare(data[i]," ") > 0) { sensorData[head[j]] = data[i]; j++; } } sensorDatas.Add(sensorData); sensorData = null; } lineCount++; } } dataGrid1.DataContext = sensorDatas; I can't figure out why this doens't work. If I change "dataGrid1.DataContext = sensorDatas;" to "dataGrid1.ItemsSource = sensorDatas;" then I get the data in the proper columns, but I also get some Raw View data such as: Comparer, Count, Keys, Values as columns, which I don't want. Any insight?

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  • realloc() & ARC

    - by RynoB
    How would I be able to rewrite the the following utility class to get all the class string values for a specific type - using the objective-c runtime functions as shown below? The ARC documentation specifically states that realloc should be avoided and I also get the following compiler error on this this line: classList = realloc(classList, sizeof(Class) * numClasses); "Implicit conversion of a non-Objective-C pointer type 'void *' to '__unsafe_unretained Class *' is disallowed with ARC" The the below code is a reference to the original article which can be found here. + (NSArray *)classStringsForClassesOfType:(Class)filterType { int numClasses = 0, newNumClasses = objc_getClassList(NULL, 0); Class *classList = NULL; while (numClasses < newNumClasses) { numClasses = newNumClasses; classList = realloc(classList, sizeof(Class) * numClasses); newNumClasses = objc_getClassList(classList, numClasses); } NSMutableArray *classesArray = [NSMutableArray array]; for (int i = 0; i < numClasses; i++) { Class superClass = classList[i]; do { superClass = class_getSuperclass(superClass); if (superClass == filterType) { [classesArray addObject:NSStringFromClass(classList[i])]; break; } } while (superClass); } free(classList); return classesArray; } Your help will be much appreciated. Thanks

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  • What vertex shader code should be used for a pixel shader used for simple 2D SpriteBatch drawing in XNA?

    - by Michael
    Preface First of all, why is a vertex shader required for a SilverlightEffect (.slfx file) in Silverlight 5? I'm trying to port a simple 2D XNA game to Silverlight 5 RC, and I would like to use a basic pixel shader. This shader works great in XNA for Windows and Xbox, but I can't get it to compile with Silverlight as a SilverlightEffect. The MS blog for the Silverlight Toolkit says that "there is no difference between .slfx and .fx", but apparently this isn't quite true -- or at least SpriteBatch is working some magic for us in "regular XNA", and it isn't in "Silverlight XNA". If I try to directly copy my pixel shader file into a Silverlight project (and change it to the supported "Effect - Silverlight" importer/processor), when I try to compile I see the following error message: Invalid effect file. Unable to find vertex shader in pass "P0" Indeed, there isn't a vertex shader in my pixel shader file. I haven't needed one with my other 2D XNA apps since I'm just doing basic SpriteBatch drawing. I tried adding a vertex shader to my shader file, using Remi Gillig's comment on this Shawn Hargreaves blog post for guidance, but it doesn't quite work. The shader file successfully compiles, and I see some semblance of my game on screen, but it's tiny, twisted, repeated, and all jumbled up. So clearly something's not quite right. The Real Question So that brings me to my real question: Since a vertex shader is required, is there a basic vertex shader function that works for simple 2D SpriteBatch drawing? And if the vertex shader requires world/view/project matricies as parameters, what values am I supposed to use for a 2D game? Can any shader pros help? Thanks!

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  • php xpath problems

    - by Phill Pafford
    I'm doing a cURL POST and get the error response back, parse it into an array but having issues with xpath now. // XML <?xml version="1.0" encoding="UTF-8" standalone="yes"?> <errors xmlns="http://host/project"> <error code="30" description="[] is not a valid email address."/> <error code="12" description="id[] does not exist."/> <error code="3" description="account[] does not exist."/> <error code="400" description="phone[] does not exist."/> </errors> // Function / Class class parseXML { protected $xml; public function __construct($xml) { if(is_file($xml)) { $this->xml = simplexml_load_file($xml); } else { $this->xml = simplexml_load_string($xml); } } public function getErrorMessage() { $in_arr = false; $el = $this->xml->xpath("//@errors"); $returned_errors = count($el); if($returned_errors > 0) { foreach($el as $element) { if(is_object($element) || is_array($element)) { foreach($element as $item) { $in_arr[] = $item; } } } } else { return $returned_errors; } return $in_arr; } } // Calling function // $errorMessage is holding the XML value in an array index // something like: $arr[3] = $xml; $errMsg = new parseXML($arr[3]); $errMsgArr = $errMsg->getErrorMessage(); What I would like is all the error code and description attribute values

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  • Basic Steps in reading Excel files into matlab

    - by user3693727
    >> [NUM,TXT,RAW]=xlsread('C:\Users\Lincoln Wachn\Google Drive\Summer time\Book1') ??? Error using ==> xlsread at 219 XLSREAD unable to open file C:\Users\Lincoln Wachn\Google Drive\Summer time\Book1. File C:\Users\Lincoln Wachn\Google Drive\Summer time\Book1.xls not found. This is the error that I have received when I try to read a simple Excel file into MATLAB. This is a snapshot of the spreadsheet I would like to load in. Could guide me the basic know-how to extract these data? I have looked through the other questions pertaining to reading Excel files into MATLAB, but I am still very confused. I ultimately wish to extract the file below for my project using the same method. The second image shows the data I have to extract which I could not do. Its file type seems to be different, it is comma separated values file which is not xls. Hence, I am also confuse about whether different file type prevents extraction of data. Thanks you for helping(:

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  • accessing $_SESSION when using file_get_contents in PHP

    - by hairdresser-101
    I have a page called send.email.php which sends an email - pretty simple stuff - I pass an order id, it creates job request and sends it out. This works fine when used in the context I developed it (Use javascript to make an AJAX call to the URL and pass the order_id as a query parameter) I am now trying to reuse the exact same page in another application however I am calling it using php file_get_contents($base_url.'admin/send.email.php?order_id='.$order_id). When I call the page this way, the $_SESSION array is empty isempty() = 1. Is this because I am initiating a new session using file_get_contents and the values I stored in the $_SESSION on login are not available to me within there? -- Thanks for the feedback. It makes sense that the new call doesn't have access to the existing session... New problem though: I now get: failed to open stream: HTTP request failed! When trying to execute: $opts = array('http' => array('header'=> 'Cookie: ' . $_SERVER['HTTP_COOKIE']."\r\n")); $context = stream_context_create($opts); $contents = file_get_contents($base_url.'admin/send.sms.php?order_id='.order_id, false, $context); YET, the URL works fine if I call it as: (It just doesn't let me access session) $result file_get_contents($base_url.'admin/send.sms.php?order_id='.$order_id);

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  • Tabs in asp.net mvc

    - by Xulfee
    I have three tabs on page and one user control. I want to RenderPartial on each tab. <script type="text/javascript"> $(document).ready(function() { $("#tabs").tabs(); }); </script> <div id="tabs"> <ul> <li><a href="#tabs-1">Text 1</a></li> <li><a href="#tabs-2">Text 2</a></li> <li><a href="#tabs-3">Text 3</a></li> </ul> <div id="tabs-1"> <% Html.RenderPartial("usercontrol", Model); %> </div> <div id="tabs-2"> <% Html.RenderPartial("usercontrol", Model); %> </div> <div id="tabs-3"> <% Html.RenderPartial("usercontrol", Model); %> </div> </div> how can i get values from different tabs.

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  • How to Load Bing Map using Coordinates from Database?

    - by Lukasz
    I have latitude and longitude saved inside a database. I have the bing map loading and I can set the VELatLong using regular values but can't seem to be able to load them from the database. Whatever I try the map just doesn't show at all. <script type="text/javascript"> var map = null; var selStyle = VEMapStyle.Road; var selMode = VEMapMode.Mode2D; var zoom = 14; var latLon = new VELatLong(40.67959657544238, -73.94073486328126); // NYC, NY var locationPin = null; function GetMap() { map = new VEMap("myMap"); map.onLoadMap = InitialPin; map.SetCredentials("--KEY HERE--"); map.LoadMap(latLon, zoom, selStyle, false, selMode, false); map.AttachEvent("onclick", OnClick_PinHandler); } window.onload = GetMap; window.onunload = DisposeMap; </script> Thanks for your help!

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  • ASP.NET MVC - Entending the Authorize Attribute

    - by Mad Halfling
    Hi folks, currently I use [Authorize(Roles = ".....")] to secure my controller actions on my ASP.NET MVC 1 app, and this works fine. However, certain search views need to have buttons that route to these actions that need to be enabled/disabled based on the record selected on the search list, and also the security privs of the user logged in. Therefore I think I need to have a class accessing a DB table which cross-references these target controller/actions with application roles to determine the state of these buttons. This will, obviously, make things messy as privs will need to be maintained in 2 places - in that class/DB table and also on the controller actions (plus, if I want to change the access to the action I will have to change the code and compile rather than just change a DB table entry). Ideally I would like to extend the [Authorize] functionality so that instead of having to specify the roles in the [Authorize] code, it will query the security class based on the user, controller and action and that will then return a boolean allowing or denying access. Are there any good articles on this - I can't imagine it's an unusual thing to want to do, but I seem to be struggling to find anything on how to do it (could be Monday-morning brain). I've started some code doing this, looking at article http://schotime.net/blog/index.php/2009/02/17/custom-authorization-with-aspnet-mvc/ , and it seems to be starting off ok but I can't find the "correct" way to get the calling controller and action values from the httpContext - I could possibly fudge a bit of code to extract them from the request url, but that doesn't seem right to me and I'd rather do it properly. Cheers MH

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  • Sorting ArrayList - IndexOutOfBoundsException -Java

    - by FILIaS
    I'm trying to sort an ArrayList with strings(PlayersNames) and imageIcons(PlayersIcons) based on the values i store in an other arrayList with integers(results). As you can see i get an indexOutOfBoundsException but i cant understand why. Maybe the earling of the morning makes me not to see plain things. ArrayList<String> PlayersNames=new ArrayList<String>; ArrayList<ImageIcon> PlayersIcons=new ArrayList<ImageIcons>; public void sortPlayers(ArrayList<Integer> results){ String tmp; ImageIcon tmp2; for (int i=0; i<PlayersNames.size(); i++) { for (int j=PlayersNames.size(); j>i; j--) { if (results.get(i) < results.get(i+1) ) { //IndexOutOfBoundsException! tmp=PlayersNames.get(i+1); PlayersNames.set(i+1,PlayersNames.get(i)); PlayersNames.set(i,tmp); tmp2=PlayersIcons.get(i+1); PlayersIcons.set(i+1,PlayersIcons.get(i)); PlayersIcons.set(i,tmp2); } } } }

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  • Converting from Latitude/Longitude to Cartesian Coordinates with a World File and map image.

    - by Heath
    I have a java applet that allows users to import a jpeg and world file from the local system. The user can then "click" draw lines on the image that was imported. Each endpoint of each line contains a set of X/Y and Lat/Long values. The XY is standard java coordinate space, the applet uses an affine transform calculation with the world file to determine the lat/long for every point on the canvas. I have a requirement that allows a user to type a distance into a text field and use the arrow key to draw a line in a certain direction (Up, Down, Left, Right) from a single selected point on the screen. I know how to determine the lat/long of a point given a source lat/long, distance, and bearing. So a user types "100" in the text field and presses the Right arrow key a line should be drawn 100 feet to the right from the currently selected point. My issue is I don't know how to convert the distance( which is in feet ) into the distance in pixels. This would then tell my where to plot the point.

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  • Help matching fields between two classes

    - by Michael
    I'm not too experienced with Java yet, and I'm hoping someone can steer me in the right direction because right now I feel like I'm just beating my head against a wall... The first class is called MeasuredParams, and it's got 40+ numeric fields (height, weight, waistSize, wristSize - some int, but mostly double). The second class is a statistical classifier called Classifier. It's been trained on a subset of the MeasuredParams fields. The names of the fields that the Classifier has been trained on is stored, in order, in an array called reqdFields. What I need to do is load a new array, toClassify, with the values stored in the fields from MeasuredParams that match the field list (including order) found in reqdFields. I can make any changes necessary to the MeasuredParams class, but I'm stuck with Classifier as it is. My brute-force approach was to get rid of the fields in MeasuredParams and use an arrayList instead, and store the field names in an Enum object to act as an index pointer. Then loop through the reqdFields list, one element at a time, and find the matching name in the Enum object to find the correct position in the arrayList. Load the value stored at that positon into toClassify, and then continue on to the next element in reqdFields. I'm not sure how exactly I would search through the Enum object - it would be a lot easier if the field names were stored in a second arrayList. But then the index positions between the two would have to stay matched, and I'm back to using an Enum. I think. I've been running around in circles all afternoon, and I keep thinking there must be an easier way of doing it. I'm just stuck right now and can't see past what I've started. Any help would be GREATLY appreciated. Thanks so much! Michael

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  • Adapting Machine Learning Algorithms to my Problem

    - by Berkay
    i'm working on a project and need your ideas, advices. First of all, let me tell my problem. There is power button and some other keys of a machine and there is only one user has authentication to use this machine.There are no other authentication methods, the machine is in public area in a company. the machine is working with the combination of pressing power button and some other keys. The order of pressing keys is secret but we don't trust it, anybody can learn the password and can access the machine. i have the capability of managing the key hold time and also some other metrics to measure the time differences between the key such as horizantal or vertical key press times (differences). and also i can measure the hold time etc. These all means i have some inputs, Now i'm trying to get a user profile by analysing these inputs. My idea is to get the authenticated user to press the password n times and create a threshold or something similar to that. This method also can be said BIOMETRICS, anyone else who knows the machine button combination, can try the password but if he is out of this range can not get access it. How can i adapt these into my algorithms? where should i start ? i don't want to delve deep into machine learning, and also i can see the in my first try i can get false positive and false negative values really high, but i can manage it by changing my inputs. thanks.

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  • Accessing a com object's vtable in c#

    - by Martin Booth
    I'm attempting to access a com object's vtable in memory and getting nowhere. From what I have read, the first 4 bytes in memory of a com object should be a pointer to the vtableptr, which in turn is a pointer to the vtable. Although I'm not sure I expect to find my test method at slot 7 in this com object I have tried them all and nothing looks like the address of my function. If anyone can make the necessary changes to this sample to get it to work (the aim is just to try and invoke the Test method on the Tester class by accessing the com object's vtable and locating the method in whichever row it turns up) I would be very grateful. I know it is rare that anyone would need to do this, but please accept I do need to do something quite similar and have considered the alternatives Thanks in advance [ComVisible(true)] public class Tester { public void Test() { MessageBox.Show("Here"); } } public delegate void TestDelegate(); private void main() { Tester t = new Tester(); GCHandle objectHandle = GCHandle.Alloc(t); IntPtr objectPtr = GCHandle.ToIntPtr(objectHandle); IntPtr vTable = (IntPtr)Marshal.ReadInt32(objectPtr); IntPtr vTablePtr = (IntPtr)Marshal.ReadInt32(vTable); IntPtr functionPtr = (IntPtr)Marshal.ReadInt32(vTablePtr, 7 * 4); // 7 may be incorrect but i have tried many different values TestDelegate func = (TestDelegate)Marshal.GetDelegateForFunctionPointer(functionPtr, typeof(TestDelegate)); func(); objectHandle.Free(); }

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  • JSF in jetty-equinox, Cannot find Bean classes in other bundles!

    - by Arnold
    Hi I have problems running JSF in an OSGi environment. I am using jetty web container and equinox to provide the OSGi functionality. The structure of my application is as follows: The first bundle has all the JSF libs, web.xml and a config.xml. It looks as the following: bundle1 ----src/main/java -------de/package ----------Activator.java ----------JSFResolver.java ----src/main/resource ------ WebContent ----------META-INF -------------face-config.xml --------------web.xhtml ----------start.xhtml -----------include.xhtml ----libs (containing all JSF required Jars) The structure of the second bundle is as follows: bundle2 ---src/main/java ------de/package ----------Bean.java ---src/main/resource ------META-INF ---------face-config.xml ------WebContent ---------index.xhtml When running the application of equinox, the bundle1 is the main bundle where all the browser requests are sent to. In the second bundle, the 'index.xhtml' file can be retrieved the by first bundle upon request. The 'index.xhtml' in bundle 2 gets its values and properties from the 'Bean.java' in bundle 2. The problem comes when i request the 'index.xhtml', the Bean.java class is not found. I think this is because the class loader of bundle1 cannot find it, it has no knowledge of it. So i would like to ask if anyone knows how to solve this problem. If so please do assist me, i have tried all the possibilities i had.. Is it infact possible to have JSF run on multiple bundles using the same FaceletsContex? Can i be able to have seperate faces-config.xml files in each bundle, which can all be connected other faces-config.xml in other bundles? Can anyone please provide me a solution. Sample code would help. thanks workspace_current.rar Arnold

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  • Using datetime float representation as primary key

    - by devanalyst
    From my experience I have learn that using an surrogate INT data type column as primary key esp. an IDENTITY key column offers better performance than using GUID or char/varchar data type column as primary key. I try to use IDENTITY key as primary key wherever possible. But recently I came across a schema where the tables were horizontally partitioned and were managed via a Partitioned view. So the tables could not have an IDENTITY column since that would make the Partitioned View non updatable. One work around for this was to create a dummy 'keygenerator' table with an identity column to generate IDs for primary key. But this would mean having a 'keygenerator' table for each of the Partitioned View. My next thought was to use float as a primary key. The reason is the following key algorithm that I devised DECLARE @KEY FLOAT SET @KEY = CONVERT(FLOAT,GETDATE())/100000.0 SET @KEY = @EMP_ID + @KEY Heres how it works. CONVERT(FLOAT,GETDATE()) gives float representation of current datetime since internally all datetime are represented by SQL as a float value. CONVERT(FLOAT,GETDATE())/100000.0 converts the float representation into complete decimal value i.e. all digits are pushed to right side of ".". @KEY = @EMP_ID + @KEY adds the Employee ID which is an integer to this decimal value. The logic is that the Employee ID is guaranteed to be unique across sessions since an employee cannot connect to an application more than once at the same time. And for the same employee each time a key will be generated the current datetime will be unique. In all an unique key across all employee sessions and across time. So for Emp Ids 11 and 12, I have key values like 12.40046693321566357, 11.40046693542361111 But my concern whether float data type as primary key offer benefits compared to choosing GUID or char/varchar as primary keys. Also important thing is because of partitioning the float column is going to be part of a composite key.

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  • How to Deserialize Missing Fields To Nulls

    - by Nathan
    I am working on a .NET project where several versions of the same type of object have been created over the life of the project - most new versions add a field or two. However, now I am looking to mitigate problems for users with an old version. My goal is that when a user tries to open an old version of the serialized object with the new program, the program will automatically assign default values to the fields that are missing from the depreciated version of the file. For example, say I had a class with two boolean fields - RepeatSound and RepeatForever. The first version of the program doesn't know how to repeat forever, so it only saved RepeatSound: <anyType xsi:type="Sound"> <RepeatSound>true</RepeatSound> </anyType> but the new files look like this: <anyType xsi:type="Sound"> <RepeatSound>true</RepeatSound> <RepeatForever>true</RepeatForever> </anyType> My goal is that when I deserialize the first file in the new program that it will create the Sound object but simply default the value of RepeatForever to false. Right now trying to deserialize the first object would throw an exception. Thank you in advance for any responses

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  • This is more a matlab/math brain teaser than a question

    - by gd047
    Here is the setup. No assumptions for the values I am using. n=2; % dimension of vectors x and (square) matrix P r=2; % number of x vectors and P matrices x1 = [3;5] x2 = [9;6] x = cat(2,x1,x2) P1 = [6,11;15,-1] P2 = [2,21;-2,3] P(:,1)=P1(:) P(:,2)=P2(:) modePr = [-.4;16] TransPr=[5.9,0.1;20.2,-4.8] pred_modePr = TransPr'*modePr MixPr = TransPr.*(modePr*(pred_modePr.^(-1))') x0 = x*MixPr Then it was time to apply the following formula to get myP , where µij is MixPr. I used this code to get it: myP=zeros(n*n,r); Ptables(:,:,1)=P1; Ptables(:,:,2)=P2; for j=1:r for i = 1:r; temp = MixPr(i,j)*(Ptables(:,:,i) + ... (x(:,i)-x0(:,j))*(x(:,i)-x0(:,j))'); myP(:,j)= myP(:,j) + temp(:); end end Some brilliant guy proposed this formula as another way to produce myP for j=1:r xk1=x(:,j); PP=xk1*xk1'; PP0(:,j)=PP(:); xk1=x0(:,j); PP=xk1*xk1'; PP1(:,j)=PP(:); end myP = (P+PP0)*MixPr-PP1 I tried to formulate the equality between the two methods and seems to be this one. To make things easier, I ignored from both methods the summation of matrix P. where the first part denotes the formula that I used, while the second comes from his code snippet. Do you think this is an obvious equality? If yes, ignore all the above and just try to explain why. I could only start from the LHS, and after some algebra I think I proved it equals to the RHS. However I can't see how did he (or she) think of it in the first place.

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  • asp.net mvc formcollection

    - by mazhar
    public ActionResult Edit(int id, FormCollection formValues) { 07. 08. // Retrieve existing dinner 09. Dinner dinner = dinnerRepository.GetDinner(id); 10. 11. // Update dinner with form posted values 12. dinner.Title = Request.Form["Title"]; 13. dinner.Description = Request.Form["Description"]; 14. dinner.EventDate = DateTime.Parse(Request.Form["EventDate"]); 15. dinner.Address = Request.Form["Address"]; 16. dinner.Country = Request.Form["Country"]; 17. dinner.ContactPhone = Request.Form["ContactPhone"]; 18. 19. // Persist changes back to database 20. dinnerRepository.Save(); 21. 22. // Perform HTTP redirect to details page for the saved Dinner 23. return RedirectToAction("Details", new { id = dinner.DinnerID }); 24.} formValues is not used in any form, what is the used of it.

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  • move_uploaded_file() error

    - by James R.
    I have a website on free hosting - 000webhost.com and it allows you to upload images. However, when I try to upload an image, I get these errors: Warning: move_uploaded_file(images/SmallSmileyFace.jpg) [function.move-uploaded-file]: failed to open stream: Permission denied in /home/a6621074/public_html/m/write.php on line 76 Warning: move_uploaded_file() [function.move-uploaded-file]: Unable to move '/tmp/phpcmW3mo' to 'images/SmallSmileyFace.jpg' in /home/a6621074/public_html/m/write.php on line 76 This is the code: if (!empty($_FILES['fileImage']['name'])) { // check image type and size if ((($imagetype == 'image/gif') || ($imagetype == 'image/jpeg') || ($imagetype == 'image/pjpeg') || ($imagetype == 'image/png')) && ($imagesize > 0) && ($imagesize <= 32768)) { if ($_FILES['fileImage']['error'] == 0) { //move file $target = 'images/' . $image; if (move_uploaded_file($_FILES['fileImage']['tmp_name'], $target)) { $query = "INSERT INTO reviews (post_date, food_name, location, cafeteria, review, image, rating, user_id) VALUES (NOW(), '$foodname', '$location', '$cafeteria', '$review', '$image', $rate, $id)"; mysqli_query($dbc, $query); //confirm success echo '<p>Thank you for your submission!</p>'; } else { echo '<p class="errmsg">There was a problem uploading your image.</p>'; } } @unlink($_FILES['fileImage']['tmp_name']); } else { echo '<p class="errmsg">The screen shot must be a GIF, JPEG, or PNG image file no greater than 32KB in size.</p>'; } } Any ideas?

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  • Boost Mersenne Twister: how to seed with more than one value?

    - by Eamon Nerbonne
    I'm using the boost mt19937 implementation for a simulation. The simulation needs to be reproducible, and that means storing and potentially reusing the RNG seeds later. I'm using the windows crypto api to generate the seed values because I need an external source for the seeds and not because of any particular guarantees of randomness. The output of any simulation run will have a note including the RNG seed - so the seed needs to be reasonably short. On the other hand, as part of the analysis of the simulation, I'll be comparing several runs - but to be sure that these runs are actually different, I'll need to use different seeds - so the seed needs to be long enough to avoid accidental collisions. I've determined that 64-bits of seeding should suffice; the chance of a collision will reach 50% after about 2^32 runs - that probability is low enough that the average error caused by it is negligible to me. Using just 32-bits of seed is tricky; the chance of a collision reaches 50% already after 2^16 runs; and that's a little too likely for my tastes. Unfortunately, the boost implementation either seeds with a full state vector - which is far, far too long - or a single 32-bit unsigned long - which isn't ideal. How can I seed the generator with more than 32-bits but less than a full state vector? I tried just padding the vector or repeating the seeds to fill the state vector, but even a cursory glance at the results shows that that generates poor results.

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  • How would you answer Joel's sample programming questions?

    - by Khorkrak
    I recently interviewed a candidate for a new position here. I wish though that I'd read Joel's Guerrilla Guide to Interviewing prior to that interview - naturally I happened upon it the night afterwards :P http://www.joelonsoftware.com/articles/GuerrillaInterviewing3.html So I tried answering the easy questions myself - yeah I used the python interpreter to type stuff in and tested the results a bit - I didn't look up any solutions beforehand though and I also thought about how long it took me to come up with answers for each one and what I'd look for the next time I interview someone. I'd let them type stuff into the interpreter and see how did used python's introspection capabilities too to find out things like what's the re module's method for building a regex etc. Here are my answers - these are in python of course - what are yours in your favourite language? Do you see any issues with the answers I came up with - i.e. how could they be improved upon - what did I miss? Joel's example questions: Write a function that determines if a string starts with an upper-case letter A-Z. import re upper_regex = re.compile("^[A-Z]") def starts_with_upper(text): return upper_regex.match(text) is not None Write a function that determines the area of a circle given the radius. from math import pi def area(radius): return pi * radius**2 Add up all the values in an array. sum([1, 2, 3, 4, 5]) Harder Question: Write an example of a recursive function - so how about the classic factorial one: def factorial(num): if num > 1: return num * factorial(num - 1) else: return 1

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  • Dynamic where clause using Linq to SQL in a join query in a MVC application

    - by jhoefnagels
    Dear .Net Linq experts, I am looking for a way to query for products in a catalog using filters on properties which have been assigned to the product based on the category to which the product belongs. So I have the following entities involved: Products -Id -CategoryId Categories [Id] Properties [Id, CategoryId] PropertyValues [Id, PropertyId] ProductProperties [ProductId, PropertyValueId] When I ad a product to the catalog, multiple ProductProperties will be added based on the category and I would like to be able to filter all products from a category by selecting values for one or more properties. I will gather all filters, which I will hold in a list, by reading the URL. Now it is time to actually get the products based on multiple properties and I have been trying to find the right strategy but untill now it does not really work. Is there a way to make this work without writing SQL? I was trying something like this: productsInCategory = ProductRepository.Where(p => p.Category.Name == category); foreach (PropertyFilter pf in filterList) { productsInCategory = (from product in productsInCategory join pp in ProductPropertyRepository on product.Id equals pp.ProductId where pp.PropertyValueId == pf.ValueId select product); }

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  • Improve speed of own debug visualizer for Delphi 2010

    - by netcodecz
    I wrote Delphi debug visualizer for TDataSet to display values of current row, source + screenshot: http://delphi.netcode.cz/text/tdataset-debug-visualizer.aspx . Working good, but very slow. I did some optimalization (how to get fieldnames) but still for only 20 fields takes 10 seconds to show - very bad. Main problem seems to be slow IOTAThread90.Evaluate used by main code shown below, this procedure cost most of time, line with ** about 80% time. FExpression is name of TDataset in code. procedure TDataSetViewerFrame.mFillData; var iCount: Integer; I: Integer; // sw: TStopwatch; s: string; begin // sw := TStopwatch.StartNew; iCount := StrToIntDef(Evaluate(FExpression+'.Fields.Count'), 0); for I := 0 to iCount - 1 do begin s:= s + Format('%s.Fields[%d].FieldName+'',''+', [FExpression, I]); // FFields.Add(Evaluate(Format('%s.Fields[%d].FieldName', [FExpression, I]))); FValues.Add(Evaluate(Format('%s.Fields[%d].Value', [FExpression, I]))); //** end; if s<> '' then Delete(s, length(s)-4, 5); s := Evaluate(s); s:= Copy(s, 2, Length(s) -2); FFields.CommaText := s; { sw.Stop; s := sw.Elapsed; Application.MessageBox(Pchar(s), '');} end; Now I have no idea how to improve performance.

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  • Get Mechanize to handle cookies from an arbitrary POST (to log into a website programmatically)

    - by Horace Loeb
    I want to log into https://www.t-mobile.com/ programmatically. My first idea was to use Mechanize to submit the login form: However, it turns out that this isn't even a real form. Instead, when you click "Log in" some javascript grabs the values of the fields, creates a new form dynamically, and submits it. "Log in" button HTML: <button onclick="handleLogin(); return false;" class="btnBlue" id="myTMobile-login"><span>Log in</span></button> The handleLogin() function: function handleLogin() { if (ValidateMsisdnPassword()) { // client-side form validation logic var a = document.createElement("FORM"); a.name = "form1"; a.method = "POST"; a.action = mytmoUrl; // defined elsewhere as https://my.t-mobile.com/Login/LoginController.aspx var c = document.createElement("INPUT"); c.type = "HIDDEN"; c.value = document.getElementById("myTMobile-phone").value; // the value of the phone number input field c.name = "txtMSISDN"; a.appendChild(c); var b = document.createElement("INPUT"); b.type = "HIDDEN"; b.value = document.getElementById("myTMobile-password").value; // the value of the password input field b.name = "txtPassword"; a.appendChild(b); document.body.appendChild(a); a.submit(); return true } else { return false } } I could simulate this form submission by POSTing the form data to https://my.t-mobile.com/Login/LoginController.aspx with Net::HTTP#post_form, but I don't know how to get the resultant cookie into Mechanize so I can continue to scrape the UI available when I'm logged in. Any ideas?

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