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• problem with joomla, php and json

  - by sebastian

  hi, i have a problem with a joomla component. i'm, unsing php and json for some dynamic drop down boxes. here is the code:` jQuery( function () { //jQuery.ajaxSetup({error : function (a,b) {console.dir(a); console.dir(b);}}); jQuery("#util, #loc").change( function() { var locatie = jQuery("#loc").val(); var utilitate = jQuery("#util").val(); if ( (locatie!= '---') && (utilitate!='---') ) jQuery.getJSON( "index.php?option=com_calculator&opt=json_contor&format=raw", { locatie: locatie, utilitate: utilitate }, function (data) { var html = ""; if ( data.success == 'ok' ) for (var i in data.val) html += "<option name=den_contor value ='"+ i+"' >" + data.val[i]+ " </option>"; jQuery("#den_contor").html( html ) } ) }) }); the query works, but only on one PC. we have exactly the same xampp server, exactly the same files. on one pc it works, and on a online server and on my pc it doesn't. EDIT: i have three drop down boxes, the first is populated directly from the database, the second has 4 predefined values. and the third is populated depending on combination of the first two. i have a test site online. http://contor.redxart.com must be logged in to use Calculator in the menu. you can make an new account :) "Adaugare Index" is the part that isn't working any ideas? thanks, sebastian

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• Cant seem to get CSS working on an appended table

  - by battlenub

  I have an ajax request to a php file returning me rows of 3 values each. I want to append these into a table. This works. I get my info in my table but I can't seem to add classes or id's and get some styling on it. http://jsfiddle.net/AKh4n/1/ success : function(data) { $('#lijstbeh').empty(); var data2 = jQuery.parseJSON(data); $('#lijstbeh').append('<table class="table">'); $('#lijstbeh').append('<tr>'); $('#lijstbeh').append('<th>Behandeling ID</th>'); $('#lijstbeh').append('<th>Behandeling kort</th>'); $('#lijstbeh').append('<th>Behandeling datum</th>'); $('#lijstbeh').append('</tr>'); $.each (data2,function (bb) { $('#lijstbeh').append('<tr class="tblbehandelingen">'); $('#lijstbeh').append('<td>' + data2[bb].BEH_ID + '</td>'); $('#lijstbeh').append('<td>' + data2[bb].BEH_behandelingkort + '</td>'); $('#lijstbeh').append('<td>' + data2[bb].BEH_datum + '</td>'); $('#lijstbeh').append('</tr>'); }); $('#lijstbeh').append('</table>'); }

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• Merge computed data from two tables back into one of them

  - by Tyler McHenry

  I have the following situation (as a reduced example). Two tables, Measures1 and Measures2, each of which store an ID, a Weight in grams, and optionally a Volume in fluid onces. (In reality, Measures1 has a good deal of other data that is irrelevant here) Contents of Measures1: +----+----------+--------+ | ID | Weight | Volume | +----+----------+--------+ | 1 | 100.0000 | NULL | | 2 | 200.0000 | NULL | | 3 | 150.0000 | NULL | | 4 | 325.0000 | NULL | +----+----------+--------+ Contents of Measures2: +----+----------+----------+ | ID | Weight | Volume | +----+----------+----------+ | 1 | 75.0000 | 10.0000 | | 2 | 400.0000 | 64.0000 | | 3 | 100.0000 | 22.0000 | | 4 | 500.0000 | 100.0000 | +----+----------+----------+ These tables describe equivalent weights and volumes of a substance. E.g. 10 fluid ounces of substance 1 weighs 75 grams. The IDs are related: ID 1 in Measures1 is the same substance as ID 1 in Measures2. What I want to do is fill in the NULL volumes in Measures1 using the information in Measures2, but keeping the weights from Measures1 (then, ultimately, I can drop the Measures2 table, as it will be redundant). For the sake of simplicity, assume that all volumes in Measures1 are NULL and all volumes in Measures2 are not. I can compute the volumes I want to fill in with the following query: SELECT Measures1.ID, Measures1.Weight, (Measures2.Volume * (Measures1.Weight / Measures2.Weight)) AS DesiredVolume FROM Measures1 JOIN Measures2 ON Measures1.ID = Measures2.ID; Producing: +----+----------+-----------------+ | ID | Weight | DesiredVolume | +----+----------+-----------------+ | 4 | 325.0000 | 65.000000000000 | | 3 | 150.0000 | 33.000000000000 | | 2 | 200.0000 | 32.000000000000 | | 1 | 100.0000 | 13.333333333333 | +----+----------+-----------------+ But I am at a loss for how to actually insert these computed values into the Measures1 table. Preferably, I would like to be able to do it with a single query, rather than writing a script or stored procedure that iterates through every ID in Measures1. But even then I am worried that this might not be possible because the MySQL documentation says that you can't use a table in an UPDATE query and a SELECT subquery at the same time, and I think any solution would need to do that. I know that one workaround might be to create a new table with the results of the above query (also selecting all of the other non-Volume fields in Measures1) and then drop both tables and replace Measures1 with the newly-created table, but I was wondering if there was any better way to do it that I am missing.

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• how to send image to remote server using web services in android

  - by Aswan

  get image from sdcard and store that image to remote server. i am getting the image from sdcard and i converterd that image to bytearray by using bitmap .but what's the problem if i oberver byte array it is showing some different values it is not matching with .net image byte array conversion. can u pl help if you have any solution it is very urgent to me following is the code i am using can u pl suggest me FileInputStream fin = new FileInputStream(new File("/sdcard/pictures/1.jpg")); BufferedInputStream bis = new BufferedInputStream(fin,3000); byte[] data = new byte[bis.available()]; bis.read(data, 0, data.length); byte[] data1=new byte[data.length]; for (int i = 0; i < data.length; i++) { System.out.print(data[i]); data1[i]=data[i]; } System.out.println("5..................."+data1); Bitmap bitmap = BitmapFactory.decodeByteArray(data1,0,data1.length); System.out.println("6..................."+data1.length); Log.v("hgfjohfjghjdfhgj",""+bitmap); if(bitmap!=null) image.setImageBitmap(bitmap); else Log.e("Bitmap "," Not Created");

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• Session variables not getting set but only in Internet Explorer and not on all machines

  - by gaoshan88

  Logging into a site I'm working on functions as expected on my local machine but fails on the remote server but ONLY in Internet Explorer. The kicker is that it works in IE locally, just not on the remote machine. What in the world could cause this? I have stepped through the code on the remote machine and can see the entered login values being checked in the database, they are found and then a login function is called. This sets two $_SESSION variables and redirects to the main admin page. However, in IE only (and not when run on local machine... this is key) the $_SESSION variables are not present by the time you get to the main admin page. var_dump($_SESSION) gives me what I expect on every browser when I am running this in my local environment and in every browser except IE 6, 7 and 8 when run on the remote server (where I get a null value as if nothing has been set for $_SESSION). This really has me stumped so any advice is appreciated. For an example... in IE, run locally, var_dump gives me: array 'Username' => string 'theusername' length=11 'UserID' => string 'somevalue' length=9 Run on the remote server (IE only... works fine in other browsers) var_dump gives me: array(0){} Code: $User = GetUser($Username, $Password); if ($User->UserID <> "") { // this works so we call Login()... Login($User); // this also works and gives expected results. on to redirect... header("Location: index.php"); // a var_dump at index.php shows that there is no session data at all in IE, remotely. } else { header("Location: login.php"); } function Login($data) { $_SESSION['Username'] = $data->Username; $_SESSION['UserID'] = $data->UserID; // a var dump here gives the expected data in every browser }

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• NSPopupButton Bindings with Value Transformer

  - by rdelmar

  I don't know if what I see with a popup button populated by bindings with a value transformer is the way it's supposed to be or not -- the unusual thing I'm seeing (at least with respect to what I've seen with value transformers and table views) is that the "value" parameter in the transformedValue: method is the whole array bound to the array controller, not the individual strings in the array. When I've done this with table views, the transformer is called once for each displayed row in the table, and the "value" parameter is whatever object is bound to that row and column, not the whole array that serves as the content array for the array controller. I have a very simple app to test this. In the app delegate there is this: +(void)initialize { RDTransformer *transformer = [[RDTransformer alloc] init]; [NSValueTransformer setValueTransformer:transformer forName:@"testTransformer"]; } - (void)applicationDidFinishLaunching:(NSNotification *)aNotification { self.theData = @[@{@"name":@"William", @"age":@"24"},@{@"name":@"Thomas", @"age":@"23"},@{@"name":@"Alexander", @"age":@"64"},@{@"name":@"James", @"age":@"47"}]; } In the RDTransformer class is this: + (Class)transformedValueClass { return [NSString class]; } +(BOOL)allowsReverseTransformation { return NO; } -(id)transformedValue:(id)value { NSLog(@"%@",value); return value; } In IB, I added an NSPopupButton to the window and an array controller to the objects list. The content array of the controller is bound to App Delegate.theData, and the Content Values of the popup button is bound to Array Controller.arrangedObjects.name with the value transformer, testTransformer. When I run the program, the log from the transformedValue: method is this: 2012-09-19 20:31:39.975 PopupBindingWithTransformer[793:303] ( ) 2012-09-19 20:31:40.019 PopupBindingWithTransformer[793:303] ( William, Thomas, Alexander, James ) This doesn't seem to be other people's experience from what I can see on SO. Is there something I'm doing wrong with either the bindings or the value transformer?

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• Visual Studio 2010 randomly unable to debug WCF service.

  - by rossisdead

  I'm running Visual Studio 2010 on a Windows 7 x64 machine, and occasionally VS is giving me the good old "The remote procedure could not be debugged.This usually indicates that debugging has not been enabled on the server" error that a lot of people ask about. My problem, though, is that it seems to only do this randomly(it can be anywhere from a few minutes to a few hours), and after I've made plenty of successful calls to the service already. It doesn't prevent the service from working. It still returns values and doesn't throw any errors. The only difference is that annoying dialog pops up everytime I start to debug my application. I should mention that I'm connecting the WCF service from a WPF application. If I launch the web site the service is part of, I don't get the dialog. A few of the things I've tried that do not work: Killing and restarting the server. Compiling the web server in x86 Enabling tracing, but couldn't find any problems. Is this just a bug in Visual Studio 2010, or is there something I'm missing?

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• Is it possible to filter data used by pivot table based on filtering the rows in a source table in Excel?

  - by Geoffrey Stoel

  I have developed a dashboard in Excel 2007 that uses one source table in a sheet (being filled with a query on our data warehouse) and multiple pivot tables making different cross sections on this data. I use the GETPIVOTDATA in almost a hundred formulas to give me the right value for a specific indicator in my dashboard. This all works fine. However I now have received the question to make the dashboard for 5 different segments. As you can imagine I don't want to create 5 different workbooks for this and need to maintain the dashboard logic on all of them. So my question is the following. Is it possible to automatically (through VBA or any other means) filter the results in my source table which is the source for my pivot tables and thus for my dashboard values. So schematically: DATABASE_VIEW -- SOURCE_TABLE -- 12 pivot tables -- 100 GETPIVOTDATA functions Preferably I would like to load all the segments in the source_table (one view on my database) and then filter the data in the source table, which results in filterd source_dat for my pivots. This way I can (without requerying the db) quickly change between segments in the dashboards (refreshing pivots only). Data in the source table has the column: CUSTOMER_SEGMENT available to filter upon. Any help is appreciated. Geoffrey

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• How can I have 2 ADO access methods use the same Transaction?

  - by KevinDeus

  I'm writing a test to see if my LINQ to Entity statement works.. I'll be using this for others if I can get this concept going.. my intention here is to INSERT a record with ADO, then verify it can be queried with LINQ, and then ROLLBACK the whole thing at the end. I'm using ADO to insert because I don't want to use the object or the entity model that I am testing. I figure that a plain ADO INSERT should do fine. problem is.. they both use different types of connections. is it possible to have these 2 different data access methods use the same TRANSACTION so I can roll it back?? _conn = new SqlConnection(_connectionString); _conn.Open(); _trans = _conn.BeginTransaction(); var x = new SqlCommand("INSERT INTO Table1(ID, LastName, FirstName, DateOfBirth) values('127', 'test2', 'user', '2-12-1939');", _conn); x.ExecuteNonQuery(); //So far, so good. Adding a record to the table. //at this point, we need to do **_trans.Commit()** here because our Entity code can't use the same connection. Then I have to manually delete in the TestHarness.TearDown.. I'd like to eliminate this step //(this code is in another object, I'll include it for brevity. Imagine that I passed the connection in) //check to see if it is there using (var ctx = new XEntities(_conn)) //can't do this.. _conn is not an EntityConnection! { var retVal = (from m in ctx.Table1 where m.first_name == "test2" where m.last_name == "user" where m.Date_of_Birth == "2-12-1939" where m.ID == 127 select m).FirstOrDefault(); return (retVal != null); } //Do test.. Assert.BlahBlah(); _trans.Rollback();

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• pointer in c and the c program

  - by sandy101

  Hello, I am studying the pointer and i come to this program .... #include <stdio.h> void swap(int *,int *); int main() { int a=10; int b=20; swap(&a,&b); printf("the value is %d and %d",a,b); return 0; } void swap(int *a,int*b) { int t; t=*a; *a=*b; *b=t; printf("%d and%d\n",*a,*b); } can any one tell me why this main function return the value reversed . The thing i understood till now is that the function call in c does not affect the main function and it's values . I also want to know how much the space a pointer variable occupied like integer have occupied the 2 bytes and the various application use and advantages of the pointer .... plz.... anyone help

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• Why adding custom objects to List<T> in ApplicationSettingsBase via constructor doesn't work?

  - by BadNinja

  This is pretty closely related to another SO question. Using the example below, could someone explain to me why adding a new List<Foo> where each of Foo's properties are explicitly set causes the ApplicationSettingsBase.Save() method to correctly store the data, whereas adding a new Foo to the list via a constructor (where the constructor sets the property values) does not work? Thanks! public class Foo { public Foo(string blah, string doh) { this.Blah = blah; this.Doh = doh; } public Foo() { } public string Blah { get; set; } public string Doh { get; set; } } public sealed class MySettings : ApplicationSettingsBase { [UserScopedSetting] public List<Foo> MyFoos { get { return (List<Foo>)this["MyFoos"]; } set { this["MyFoos"] = value; } } } // Here's the question... private void button1_Click(object sender, EventArgs e) { MySettings mySettings = new MySettings(); // Adding new Foo's to the list like this doesn't work. List<Foo> theList = new List<Foo>() { new Foo("doesn't","work") }; // But doing it like this DOES work. List<Foo> theList = new List<Foo>() { new Foo() {Blah = "DOES", Doh = "work"} }; mySettings.MyFoos = theList; mySettings.Save(); }

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• Is it possible to get the parsed text of a SqlCommand with SqlParameters?

  - by Burg

  What I am trying to do is create some arbitrary sql command with parameters, set the values and types of the parameters, and then return the parsed sql command - with parameters included. I will not be directly running this command against a sql database, so no connection should be necessary. So if I ran the example program below, I would hope to see the following text (or something similar): WITH SomeTable (SomeColumn) AS ( SELECT N':)' UNION ALL SELECT N'>:o' UNION ALL SELECT N'^_^' ) SELECT SomeColumn FROM SomeTable And the sample program is: using System; using System.Data; using System.Data.SqlClient; namespace DryEraseConsole { class Program { static void Main(string[] args) { const string COMMAND_TEXT = @" WITH SomeTable (SomeColumn) AS ( SELECT N':)' UNION ALL SELECT N'>:o' UNION ALL SELECT @Value ) SELECT SomeColumn FROM SomeTable "; SqlCommand cmd = new SqlCommand(COMMAND_TEXT); cmd.CommandText = COMMAND_TEXT; cmd.Parameters.Add(new SqlParameter { ParameterName = "@Value", Size = 128, SqlDbType = SqlDbType.NVarChar, Value = "^_^" }); Console.WriteLine(cmd.CommandText); Console.ReadKey(); } } } Is this something that is achievable using the .net standard libraries? Initial searching says no, but I hope I'm wrong.

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• Deserialize xml which uses attribute name/value pairs

  - by Bodyloss

  My application receives a constant stream of xml files which are more or less a direct copy of the database record <record type="update"> <field name="id">987654321</field> <field name="user_id">4321</field> <field name="updated">2011-11-24 13:43:23</field> </record> And I need to deserialize this into a class which provides nullable property's for all columns class Record { public long? Id { get; set; } public long? UserId { get; set; } public DateTime? Updated { get; set; } } I just cant seem to work out a method of doing this without having to parse the xml file manually and switch on the field's name attribute to store the values. Is their a way this can be achieved quickly using an XmlSerializer? And if not is their a more efficient way of parsing it manually? Regards and thanks My main problem is that the attribute name needs to have its value set to a property name and its value as the contents of a <field>..</field> element

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• scanf a byte then print it out?

  - by Sarah

  I've searched around to see if I can find this answer but I can't seem to (please let me know if I'm wrong). I am trying to use scanf to read in a byte, an unsigned int and a char in one .c file and I am trying to access this byte in a different .c file and print it out. (I have already checked to make sure I have included all the appropriate parameters everywhere) But I keep getting errors. The warnings are: database.c: In function ‘addCitizen’: database.c:23:2: warning: format ‘%hhu’ expects argument of type ‘int’, but argument 2 has type ‘byte *’ [-Wformat] database.c:24:2: warning: format ‘%u’ expects argument of type ‘unsigned int’, but argument 2 has type ‘int *’ [-Wformat] database.c:25:2: warning: format ‘%c’ expects argument of type ‘int’, but argument 2 has type ‘char *’ [-Wformat] where I'm scanf'ing: // Request loop while (count-- != 0) { while (1){ // Get values from the user int error = scanf ("%79s %hhu %u %c", tname, &tdist, &tyear, &tgender); addCitizen(db, tname, &tdist, &tyear, &tgender); where I'm printing: void addCitizen(Database *db, char *tname, byte *tdist, int *tyear, char *tgender){ //needs to find the right place in memory to put this stuff and then put it there printf("\nName is: %79s\n", tname); printf("District is: %hhu\n", tdist); printf("Year of birth is: %u\n", tyear); printf("Gender is:%c\n", tgender); I'm not sure where I'm going wrong?

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• VB.Net - Launch app on Windows startup

  - by Queops

  We all now the tricky folders where your application runs when you publish your VB.NET to other people, but I won't give up on the benefits of the system (auto-update, you know). Problem is: Program is supposed to startup, or not, with Windows if the user wishes so. I'm saving program preferences into My.Settings. All fine with that. If you debug it it will save the values between sessions. The problem is after deployment. I installed the program on a testing machine. Application works okay, the settings load, if it's the user launching it by themselfs (using shortcut on desktop for example). Now upon restarting the program does indeed start up as I want it to but the My.Settings don't show up! It's like the config file has been erased. If I close program and re-open by clicking shorcut it loads the settings just fine though. So I wonder what's the problem? This is the code I use to save the registry key: regKey = Registry.CurrentUser.OpenSubKey("SOFTWARE\Microsoft\Windows\CurrentVersion\Run", True) regKey.SetValue("ScapeTracker", Chr(34) & Application.ExecutablePath & Chr(34) & " startup") Does what it's supposed to. The startup parameter is needed so the program knows if it's launched on startup on not (to show up on tray and idle there until user decides to use it). So the problem is that I can't use the settings upon restart of Windows, so I'm assuming the VB.Net applications have some extra parameters when launching? How can I solve this?

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• Draw a comparison between an integer in a specific row and a count

  - by XCoderX

  This is a follow-up question to this one: Check for specific integer in a row WHERE user = $name I want a user to be able to comment on my site for exactly five times a day. After this five times, the user has to wait 24 hours. In order to accomplish that I raise a counter in my MYSQL database, right next to the user. So where the name of the user is, there is where the counter gets raised. When it reaches 5 it should stop counting and reset after 24 hours. In order to check the time I use a timestamp. I check if the timestamp is older than 24 hours. If that is the case, the counter gets reseted (-5) and the user can comment again. In order to do that, I use the following code, however it never stops at five, my guess is that my comparison is wrong somehow: $counter = "SELECT FROM table VALUES CommentCounterReset WHERE Name = '$name'"; if(!isset($_SESSION['ts'])); { $_SESSION['ts'] = time(); } if ($counter >= 5) { if (time() - $_SESSION['ts'] <= 60*60*24){ echo "You already wrote five comments."; } else { $sql = "UPDATE table SET CommentCounterReset = CommentCounterReset-5 WHERE Name = '$name'"; } } else { $sql = "UPDATE table SET CommentCounterReset = CommentCounterReset+1 WHERE Name = '$name'"; echo "Your comment has been added."; }

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• Spring + iBatis + Hessian caching

  - by ILya

  Hi. I have a Hessian service on Spring + iBatis working on Tomcat. I'm wondering how to cache results... I've made the following config in my sqlmap file: <sqlMap namespace="Account"> <cacheModel id="accountCache" type="MEMORY" readOnly="true" serialize="false"> <flushInterval hours="24"/> <flushOnExecute statement="Account.addAccount"/> <flushOnExecute statement="Account.deleteAccount"/> <property name="reference-type" value="STRONG" /> </cacheModel> <typeAlias alias="Account" type="domain.Account" /> <select id="getAccounts" resultClass="Account" cacheModel="accountCache"> fix all; select id, name, pin from accounts; </select> <select id="getAccount" parameterClass="Long" resultClass="Account" cacheModel="accountCache"> fix all; select id, name, pin from accounts where id=#id#; </select> <insert id="addAccount" parameterClass="Account"> fix all; insert into accounts (id, name, pin) values (#id#, #name#, #pin#); </insert> <delete id="deleteAccount" parameterClass="Long"> fix all; delete from accounts where id = #id#; </delete> </sqlMap> Then i've done some tests... I have a hessian client application. I'm calling getAccounts several times and after each call it's a query to DBMS. How to make my service to query DBMS only a first time (after server restart) getAccounts called and for the following calls to use a cache?

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• confusion about using types instead of gtts in oracle

  - by Omnipresent

  I am trying to convert queries like below to types so that I won't have to use GTT: insert into my_gtt_table_1 (house, lname, fname, MI, fullname, dob) (select house, lname, fname, MI, fullname, dob from (select 'REG' house, mbr_last_name lname, mbr_first_name fname, mbr_mi MI, mbr_first_name || mbr_mi || mbr_last_name fullname, mbr_dob dob from table_1 a, table_b where a.head = b.head and mbr_number = '01' and mbr_last_name = v_last_name) c above is just a sample but complex queries are bigger than this. the above is inside a stored procedure. So to avoid the gtt (my_gtt_table_1). I did the following: create or replace type lname_row as object ( house varchar2(30) lname varchar2(30), fname varchar2(30), MI char(1), fullname VARCHAR2(63), dob DATE ) create or replace type lname_exact as table of lname_row Now in the SP: type lname_exact is table of <what_table_should_i_put_here>%rowtype; tab_a_recs lname_exact; In the above I am not sure what table to put as my query has nested subqueries. query in the SP: (I am trying this for sample purpose to see if it works) select lname_row('', '', '', '', '', '', sysdate) bulk collect into tab_a_recs from table_1; I am getting errors like : ORA-00913: too many values I am really confused and stuck with this :(

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• FileHelpers cannot map converted field into destination array

  - by jaffa

  I have the following record (reduced for brevity): [DelimitedRecord(",")] [IgnoreFirst] [IgnoreEmptyLines()] public class ImportRecord { [FieldQuoted] [FieldTrim(TrimMode.Both)] public string FirstName; [FieldQuoted] [FieldTrim(TrimMode.Both)] public string LastName; [FieldQuoted] [FieldTrim(TrimMode.Both)] [FieldOptional] [FieldConverter(typeof(TestPropertyConverter))] public int[] TestProperty; } Converter code: public class TestPropertyConverter : ConverterBase { public override object StringToField(string from) { var ret = from.Split('|').Select(x => Convert.ToInt32(x)).ToArray(); return ret; } } So an example record could be: John, Smith, 1|2|3|4 It would expect the values 1,2,3,4 to expand and fill the TestProperty array. However, I'm getting the following exception: At least one element in the source array could not be cast down to the destination array type. I've tried to debug into the code and it seems to blow-up in the ExtractFieldValue() function inside FieldBase.cs where it tries to return out of the function. The following line seems to be the culprit: res.ToArray(ArrayType); It seems to expect the 'res' variable to be the destination type array, but it contains 1 element of the array itself. Can anyone suggest if I'm doing this wrong or a possible fix?

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• TicTacToe strategic reduction

  - by NickLarsen

  I decided to write a small program that solves TicTacToe in order to try out the effect of some pruning techniques on a trivial game. The full game tree using minimax to solve it only ends up with 549,946 possible games. With alpha-beta pruning, the number of states required to evaluate was reduced to 18,297. Then I applied a transposition table that brings the number down to 2,592. Now I want to see how low that number can go. The next enhancement I want to apply is a strategic reduction. The basic idea is to combine states that have equivalent strategic value. For instance, on the first move, if X plays first, there is nothing strategically different (assuming your opponent plays optimally) about choosing one corner instead of another. In the same situation, the same is true of the center of the walls of the board, and the center is also significant. By reducing to significant states only, you end up with only 3 states for evaluation on the first move instead of 9. This technique should be very useful since it prunes states near the top of the game tree. This idea came from the GameShrink method created by a group at CMU, only I am trying to avoid writing the general form, and just doing what is needed to apply the technique to TicTacToe. In order to achieve this, I modified my hash function (for the transposition table) to enumerate all strategically equivalent positions (using rotation and flipping functions), and to only return the lowest of the values for each board. Unfortunately now my program thinks X can force a win in 5 moves from an empty board when going first. After a long debugging session, it became apparent to me the program was always returning the move for the lowest strategically significant move (I store the last move in the transposition table as part of my state). Is there a better way I can go about adding this feature, or a simple method for determining the correct move applicable to the current situation with what I have already done?

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• Efficient way to store order in mySQL for list of items

  - by ninumedia

  I want to code cleaner and more efficiently and I wanted to know any other suggestions for the following problem: I have a mySQL database that holds data about a set of photograph names. Oh, say 100 photograph names Table 1: (photos) has the following fields: photo_id, photo_name Ex data: 1 | sunshine.jpg 2 | cloudy.jpg 3 | rainy.jpg 4 | hazy.jpg ... Table 2: (categories) has the following fields: category_id, category_name, category_order Ex data: 1 | Summer Shots | 1,2,4 2 | Winter Shots | 2,3 3 | All Seasons | 1,2,3,4 ... Is it efficient to store the order of the photos in this manner per entry via comma delimited values? It's one approach I have seen used before but I wanted to know if something else is faster in run time. Using this way I don't think it is possible to do a direct INNER JOIN on the category table and photo table to get a single matched list of all the photographs per category. Ex: Summer shots - sunshine.jpg, cloudy.jpg, hazy.jpg because it was matched against 1,2,4 The iteration through all the categories and then the photos will have a O(n^2) and there has to be a better/faster way. Please educate me :)

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• Summarising grouped records in a dataframe in R

  - by monch1962

  Hello all, I have a data frame in R that looks like this: > TimeOffset, Source, Length > 0 1 1500 > 0.1 1 1000 > 0.2 1 50 > 0.4 2 25 > 0.6 2 3 > 1.1 1 1500 > 1.4 1 18 > 1.6 2 2500 > 1.9 2 18 > 2.1 1 37 > ... and I want to convert it to > TimeOffset, Source, Length > 0.2 1 2550 > 0.6 2 28 > 1.4 1 1518 > 1.9 2 2518 > ... Trying to put this into English, I want to group consecutive records with the same 'Source' together, then printing out a single record per group showing the highest time offset in that group, the source, and the sum of the lengths in that group. The TimeOffset values will always increase. I suspect this is possible in R, but I really don't know where to start. In a pinch I could export the data frame out and do it in e.g. Python, but I'd prefer to stay within R if possible. Thanks in advance for any assistance you can provide

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• Summarising grouped records in a dataframe in R (...again)

  - by monch1962

  Hello all, (I tried to ask this question earlier today, but later realised I over-simplified the question; the answers I received were correct, but I couldn't use them because of my over-simplification of the problem in the original question. Here's my 2nd attempt...) I have a data frame in R that looks like: "Timestamp", "Source", "Target", "Length", "Content" 0.1 , P1 , P2 , 5 , "ABCDE" 0.2 , P1 , P2 , 3 , "HIJ" 0.4 , P1 , P2 , 4 , "PQRS" 0.5 , P2 , P1 , 2 , "ZY" 0.9 , P2 , P1 , 4 , "SRQP" 1.1 , P1 , P2 , 1 , "B" 1.6 , P1 , P2 , 3 , "DEF" 2.0 , P2 , P1 , 3 , "IJK" ... and I want to convert this to: "StartTime", "EndTime", "Duration", "Source", "Target", "Length", "Content" 0.1 , 0.4 , 0.3 , P1 , P2 , 12 , "ABCDEHIJPQRS" 0.5 , 0.9 , 0.4 , P2 , P1 , 6 , "ZYSRQP" 1.1 , 1.6 , 0.5 , P1 , P2 , 4 , "BDEF" ... Trying to put this into English, I want to group consecutive records with the same 'Source' and 'Target' together, then print out a single record per group showing the StartTime, EndTime & Duration (=EndTime-StartTime) for that group, along with the sum of the Lengths for that group, and a concatenation of the Content (which will all be strings) in that group. The TimeOffset values will always increase throughout the data frame. I had a look at melt/recast and have a feeling that it could be used to solve the problem, but couldn't get my head around the documentation. I suspect it's possible to do this within R, but I really don't know where to start. In a pinch I could export the data frame out and do it in e.g. Python, but I'd prefer to stay within R if possible. Thanks in advance for any assistance you can provide

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• Why is BorderLayout calling setSize() and setBounds()?

  - by ags

  I'm trying to get my head around proper use of the different LayoutManagers to make my GUI design skills more efficient and effective. For me, that usually requires a detailed understanding of what is going on under the hood. I've found some good discussion of the interaction and consequences of a Container using BorderLayout containing a Container using FlowLayout. I understand it for the most part, but wanted to confirm my mental model and to do so I am looking at the code for BorderLayout. In the code snippet below taken from BorderLayout.layoutContainer(), note the calls to the child Component's setSize() method followed by setBounds(). Looking at the source for these methods of Component, setSize() actually calls setBounds() with the current values for Component.x and Component.y. Why is this done (and not entirely redudant?) Doesn't the setBounds() call completely overwrite the results of the setSize() call? if ((c=getChild(NORTH,ltr)) != null) { c.setSize(right - left, c.height); Dimension d = c.getPreferredSize(); c.setBounds(left, top, right - left, d.height); top += d.height + vgap; } I'm also tring to understand where/when the child Component's size is initially set (before the LayoutManager.layoutContainer() method is called). Finally, this post itself raises a "meta-question": in a situation like this, where the source is available elsewhere, is the accepteed protocol to include the entire method? Or some other way to make it easier for folks to participate in the thread? Thanks.

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• Why doesn't java.lang.Number implement Comparable?

  - by Julien Chastang

  Does anyone know why java.lang.Number does not implement Comparable? This means that you cannot sort Numbers with Collections.sort which seems to me a little strange. Post discussion update: Thanks for all the helpful responses. I ended up doing some more research about this topic. The simplest explanation for why java.lang.Number does not implement Comparable is rooted in mutability concerns. For a bit of review, java.lang.Number is the abstract super-type of AtomicInteger, AtomicLong, BigDecimal, BigInteger, Byte, Double, Float, Integer, Long and Short. On that list, AtomicInteger and AtomicLong to do not implement Comparable. Digging around, I discovered that it is not a good practice to implement Comparable on mutable types because the objects can change during or after comparison rendering the result of the comparison useless. Both AtomicLong and AtomicInteger are mutable. The API designers had the forethought to not have Number implement Comparable because it would have constrained implementation of future subtypes. Indeed, AtomicLong and AtomicInteger were added in Java 1.5 long after java.lang.Number was initially implemented. Apart from mutability, there are probably other considerations here too. A compareTo implementation in Number would have to promote all numeric values to BigDecimal because it is capable of accommodating all the Number sub-types. The implication of that promotion in terms of mathematics and performance is a bit unclear to me, but my intuition finds that solution kludgy.

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