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  • How to do pointer work with accessor methods in Objective-C

    - by Jasconius
    Basic problem statement: I have a very good reason for doing some pointer fanciness in an app where I need to pass a decimal by reference. So I have a class which stores many a decimal, so let's say is has a property as such: @property (nonatomic) double myDecimalValue; I want to pass it by reference to some other class. [someOtherObject sendMyDecimalByReference:&myDecimalValue]; But, a problem emerges! The way that actually has to be written (because it's a property) is [someOtherObject sendMyDecimalByReference:&decimalOrigin.myDecimalValue]; This fails to compile in objective-c I get around it by writing the following - (double *) myDecimalValueRef; [someOtherObject sendMyDecimalByReference:[decimalOrigin myDecimalValue]]; Except I have dozens of these decimals and I don't want to write that stupid wrapper function for every value. Is there a shorthand way to do this in Objective-C using just the Getter functions? Let's just assume I have a great reason for not using NSNumber. Thanks!

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  • Automatic Schema Validation using NHibernate/ActiveRecord

    - by Krembo
    Hi, let's assume I have a table of Products with columns: Id, Name, Price and using NHibernate (or ActiveRecord) I map the table to the POCO: public class Product { public virtual long Id { get; set; } public virtual string Name { get; set; } public virtual double Price { get; set; } } Now if someday a new column named ShipmentPrice (let's assume it's double too) will be added to the Products table, is there any way I can automatically know that. For saying automatically I mean adding code to do that or getting an exception? (I assume I don't have control on the columns of the table or a way to know of any changes to the table's schema in advance)

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  • C# - Angle between two 2d vectors, diff between two methods?

    - by Sean Ochoa
    Hey all. I've got this code snippet, and I'm wondering why the results of the first method differ from the results of the second method, given the same input? public double AngleBetween_1(vector a, vector b) { var dotProd = a.Dot(b); var lenProd = Len*b.Len; var divOperation = dotProd/lenProd; return Math.Acos(divOperation) * (180.0 / Math.PI); } public double AngleBetween_2(vector a, vector b) { var dotProd = a.Dot(b); var lenProd = Len*b.Len; var divOperation = dotProd/lenProd; return (1/Math.Cos(divOperation)) * (180.0 / Math.PI); }

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  • Vertical Scroll not working, are the guides but the screen does not scroll.

    - by Leandro
    package com.lcardenas.infoberry; import net.rim.device.api.system.DeviceInfo; import net.rim.device.api.system.GPRSInfo; import net.rim.device.api.system.Memory; import net.rim.device.api.ui.MenuItem; import net.rim.device.api.ui.component.Dialog; import net.rim.device.api.ui.component.LabelField; import net.rim.device.api.ui.component.Menu; import net.rim.device.api.ui.component.SeparatorField; import net.rim.device.api.ui.container.MainScreen; import net.rim.device.api.ui.container.VerticalFieldManager; import net.rim.device.api.ui.decor.Background; import net.rim.device.api.ui.decor.BackgroundFactory; public class vtnprincipal extends MainScreen { //llamamos a la clase principal private InfoBerry padre; //variables para el menu private MenuItem mnubateria; private MenuItem mnuestado; private MenuItem mnuacerca; public vtnprincipal(InfoBerry padre) { super(); this.padre = padre; } public void incventana(){ VerticalFieldManager _ventana = new VerticalFieldManager(VerticalFieldManager.VERTICAL_SCROLL | VerticalFieldManager.VERTICAL_SCROLLBAR); double tmemoria =((DeviceInfo.getTotalFlashSize()/1024)/1024.00); double fmemoria = ((Memory.getFlashFree()/1024)/1024.00); Background cyan = BackgroundFactory.createSolidBackground(0x00E0FFFF); Background gris = BackgroundFactory.createSolidBackground(0x00DCDCDC ); //Borramos todos de la pantalla this.deleteAll(); //llamamos al menu incMenu(); //DIBUJAMOS LA VENTANA try{ LabelField title = new LabelField("Info Berry", LabelField.FIELD_HCENTER | LabelField.USE_ALL_HEIGHT ); setTitle(title); _ventana.add(new LabelField("Información del Dispositivo", LabelField.FIELD_HCENTER |LabelField.RIGHT | LabelField.USE_ALL_HEIGHT | LabelField.NON_FOCUSABLE )); _ventana.add(new SeparatorField()); _ventana.add(new SeparatorField()); txthorizontal modelo = new txthorizontal("Modelo:", DeviceInfo.getDeviceName()); modelo.setBackground(gris); _ventana.add(modelo); txthorizontal pin = new txthorizontal("PIN:" , Integer.toHexString(DeviceInfo.getDeviceId()).toUpperCase()); pin.setBackground(cyan); _ventana.add(pin); txthorizontal imeid = new txthorizontal("IMEID:" , GPRSInfo.imeiToString(GPRSInfo.getIMEI())); imeid.setBackground(gris); _ventana.add(imeid); txthorizontal version= new txthorizontal("SO Versión:" , DeviceInfo.getSoftwareVersion()); version.setBackground(cyan); _ventana.add(version); txthorizontal plataforma= new txthorizontal("SO Plataforma:" , DeviceInfo.getPlatformVersion()); plataforma.setBackground(gris); _ventana.add(plataforma); txthorizontal numero= new txthorizontal("Numero Telefonico: " , "Hay que firmar"); numero.setBackground(cyan); _ventana.add(numero); _ventana.add(new SeparatorField()); _ventana.add(new SeparatorField()); _ventana.add(new LabelField("Memoria", LabelField.FIELD_HCENTER | LabelField.USE_ALL_HEIGHT | LabelField.NON_FOCUSABLE)); _ventana.add(new SeparatorField()); txthorizontal totalm= new txthorizontal("Memoria app Total:" , mmemoria(tmemoria) + " Mb"); totalm.setBackground(gris); _ventana.add(totalm); txthorizontal disponiblem= new txthorizontal("Memoria app Disponible:" , mmemoria(fmemoria) + " Mb"); disponiblem.setBackground(cyan); _ventana.add(disponiblem); ///txthorizontal estadoram = new txthorizontal("Memoria RAM:" , mmemoria(prueba) + " Mb"); //estadoram.setBackground(gris); //add(estadoram); _ventana.add(new SeparatorField()); _ventana.add(new SeparatorField()); this.add(_ventana); }catch(Exception e){ Dialog.alert("Excepción en clase vtnprincipal: " + e.toString()); } } //DIBUJAMOS EL MENU private void incMenu() { MenuItem.separator(30); mnubateria = new MenuItem("Bateria",40, 10) { public void run() { bateria(); } }; mnuestado = new MenuItem("Estado de Red", 50, 10) { public void run() { estado(); } }; mnuacerca = new MenuItem("Acerca de..", 60, 10) { public void run() { acerca(); } }; MenuItem.separator(70); }; // public void makeMenu(Menu menu, int instance) { if (!menu.isDisplayed()) { menu.deleteAll(); menu.add(MenuItem.separator(30)); menu.add(mnubateria); menu.add(mnuestado); menu.add(mnuacerca); menu.add(MenuItem.separator(60)); } } public void bateria(){ padre.vtnbateria.incventana(); padre.pushScreen(padre.vtnbateria); } public void estado(){ padre.vtnestado.incventana(); padre.pushScreen(padre.vtnestado); } public void acerca(){ padre.vtnacerca.incventana(); padre.pushScreen(padre.vtnacerca); } public boolean onClose(){ Dialog.alert("Hasta Luego"); System.exit(0); return true; } public double mmemoria(double x) { if ( x > 0 ) return Math.floor(x * 100) / 100; else return Math.ceil(x * 100) / 100; } }

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  • Function pointer arrays in Fortran

    - by Eduardo Dobay
    I can create function pointers in Fortran 90, with code like real, external :: f and then use f as an argument to another function/subroutine. But what if I want an array of function pointers? In C I would just do double (*f[])(int); to create an array of functions returning double and taking an integer argument. I tried the most obvious, real, external, dimension(3) :: f but gfortran doesn't let me mix EXTERNAL and DIMENSION. Is there any way to do what I want? (The context for this is a program for solving a system of differential equations, so I could input the equations without having a million parameters in my subroutines.)

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  • Help Understanding Function

    - by Fred F.
    What does the following function perform? public static double CleanAngle(double angle) { while (angle < 0) angle += 2 * System.Math.PI; while (angle > 2 * System.Math.PI) angle -= 2 * System.Math.PI; return angle; } This is how it is used with ATan2. I believe the actually values passed to ATan2 are always positive. static void Main(string[] args) { int q = 1; //'x- and y-coordinates will always be positive values //'therefore, do i need to "clean"? foreach (Point oPoint in new Point[] { new Point(8,20), new Point(-8,20), new Point(8,-20), new Point(-8,-20)}) { Debug.WriteLine(Math.Atan2(oPoint.Y, oPoint.X), "unclean " + q.ToString()); Debug.WriteLine(CleanAngle(Math.Atan2(oPoint.Y, oPoint.X)), "cleaned " + q.ToString()); q++; } //'output //'unclean 1: 1.19028994968253 //'cleaned 1: 1.19028994968253 //'unclean 2: 1.95130270390726 //'cleaned 2: 1.95130270390726 //'unclean 3: -1.19028994968253 //'cleaned 3: 5.09289535749705 //'unclean 4: -1.95130270390726 //'cleaned 4: 4.33188260327232 }

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  • Polygon area calculation using Latitude and Longitude generated from Cartesian space and a world fil

    - by Heath
    Given a series of GPS coordinate pairs, I need to calculate the area of a polygon (n-gon). This is relatively small (not larger than 50,000 sqft). The geocodes are created by applying an affine transform with data from a world file. I have tried to use a two step approach by doing converting the geocodes to cartesian coordinates: double xPos = (lon-lonAnchor)*( Math.toRadians( 6378137 ) )*Math.cos( latAnchor ); double yPos = (lat-latAnchor)*( Math.toRadians( 6378137 ) ); then I use a cross product calculation to determine the area. The issue is that the results are a bit off in accuracy (around 1%). Is there anything I can look into to improve this? Thanks.

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  • Sorting List which has object that contains two string members that contains numbers

    - by Lemo
    I want to know the best solution for this my case here is that i am taking values from Excel sheet and pushing them to database field, sometimes that field might contain some strings (thats why I cant make my object members int / double) In my class below size is the variable responsible for showing size of files in bytes public class dataNameValue { public string Name { get; set; } public string Count { get; set; } public string Size { get; set; } } I wanted to sort the list by file Size something like List mylist = new List(); mylist = mylist.OrderByDescending(i = i.Size).ToList(); The problem is that if i sorted it without converting it to "int/double" first -- its not giving right results

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  • Mobile Safari Geolocation API Issues

    - by sph
    Hi, since Mobile Safari's Geolocation API should be an implementation of the W3C Geolocation API I found some bugs. I was wondering if anybody noticed the same. As specified in the W3C Geolocation API the PositionCallback returns a Position object, which contains a Coordinates object. In this object all attributes are of type double. Using navigator.geolocation.getCurrentPosition and checking the Position object in the successCallback the accuracy attribute is always an object, but should be a double. The heading attribute is always -1 when testing in the iPhone simulator, but should be null or between 0 and 360. 2. Setting the options parameter for navigator.geolocation.watchPosition or navigator.geolocation.getCurrentPosition as specified in the W3C Geolocation API has no effect. No matter what is set as the timeout value, the win callback is called every 10 seconds. For example setting the timeout=1000 should immediately call either the successCallback or errorCallback. Thanks

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  • Problem with building tree bottom up

    - by Esmond
    Hi, I have problems building a binary tree from the bottom up. THe input of the tree would be internal nodes of the trees with the children of this node being the leaves of the eventual tree. So initially if the tree is empty the root would be the first internal node. Afterwards, The next internal node to be added would be the new root(NR), with the old root(OR) being one of the child of NR. And so on. The problem i have is that whenever i add a NR, the children of the OR seems to be lost when i do a inOrder traversal. This is proven to be the case when i do a getSize() call which returns the same number of nodes before and after addNode(Tree,Node) Any help with resolving this problem is appreciated edited with the inclusion of node class code. both tree and node classes have the addChild methods because i'm not very sure where to put them for it to be appropriated. any comments on this would be appreciated too. The code is as follows: import java.util.*; public class Tree { Node root; int size; public Tree() { root = null; } public Tree(Node root) { this.root = root; } public static void setChild(Node parent, Node child, double weight) throws ItemNotFoundException { if (parent.child1 != null && parent.child2 != null) { throw new ItemNotFoundException("This Node already has 2 children"); } else if (parent.child1 != null) { parent.child2 = child; child.parent = parent; parent.c2Weight = weight; } else { parent.child1 = child; child.parent = parent; parent.c1Weight = weight; } } public static void setChild1(Node parent, Node child) { parent.child1 = child; child.parent = parent; } public static void setChild2(Node parent, Node child) { parent.child2 = child; child.parent = parent; } public static Tree addNode(Tree tree, Node node) throws ItemNotFoundException { Tree tree1; if (tree.root == null) { tree.root = node; } else if (tree.root.getSeq().equals(node.getChild1().getSeq()) || tree.root.getSeq().equals(node.getChild2().getSeq())) { Node oldRoot = tree.root; oldRoot.setParent(node); tree.root = node; } else { //form a disjoint tree and merge the 2 trees tree1 = new Tree(node); tree = mergeTree(tree, tree1); } System.out.print("addNode2 = "); if(tree.root != null ) { Tree.inOrder(tree.root); } System.out.println(); return tree; } public static Tree mergeTree(Tree tree, Tree tree1) { String root = "root"; Node node = new Node(root); tree.root.setParent(node); tree1.root.setParent(node); tree.root = node; return tree; } public static int getSize(Node root) { if (root != null) { return 1 + getSize(root.child1) + getSize(root.child2); } else { return 0; } } public static boolean isEmpty(Tree Tree) { return Tree.root == null; } public static void inOrder(Node root) { if (root != null) { inOrder(root.child1); System.out.print(root.sequence + " "); inOrder(root.child2); } } } public class Node { Node child1; Node child2; Node parent; double c1Weight; double c2Weight; String sequence; boolean isInternal; public Node(String seq) { sequence = seq; child1 = null; c1Weight = 0; child2 = null; c2Weight = 0; parent = null; isInternal = false; } public boolean hasChild() { if (this.child1 == null && this.child2 == null) { this.isInternal = false; return isInternal; } else { this.isInternal = true; return isInternal; } } public String getSeq() throws ItemNotFoundException { if (this.sequence == null) { throw new ItemNotFoundException("No such node"); } else { return this.sequence; } } public void setChild(Node child, double weight) throws ItemNotFoundException { if (this.child1 != null && this.child2 != null) { throw new ItemNotFoundException("This Node already has 2 children"); } else if (this.child1 != null) { this.child2 = child; this.c2Weight = weight; } else { this.child1 = child; this.c1Weight = weight; } } public static void setChild1(Node parent, Node child) { parent.child1 = child; child.parent = parent; } public static void setChild2(Node parent, Node child) { parent.child2 = child; child.parent = parent; } public void setParent(Node parent){ this.parent = parent; } public Node getParent() throws ItemNotFoundException { if (this.parent == null) { throw new ItemNotFoundException("This Node has no parent"); } else { return this.parent; } } public Node getChild1() throws ItemNotFoundException { if (this.child1 == null) { throw new ItemNotFoundException("There is no child1"); } else { return this.child1; } } public Node getChild2() throws ItemNotFoundException { if (this.child2 == null) { throw new ItemNotFoundException("There is no child2"); } else { return this.child2; } } }

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  • How to best integrate generated code

    - by Arne
    I am evaluating the use of code generation for my flight simulation project. More specifically there is a requirement to allow "the average engineer" (no offense I am one myself) to define the differential equations that describe the dynamic system in a more natural syntax than C++ provides. The idea is to devise a abstract descriptor language that can be easily understood and edited to generate C++ code from. This descriptor is supplied by the modeling engineer and used by the ones implementing and maintaining the simulation evironment to generate code. I've got something like this in mind: model Aircraft has state x1, x2; state x3; input double : u; input bool : flag1, flag2; algebraic double : x1x2; model Engine : tw1, tw2; model Gear : gear; model ISA : isa; trim routine HorizontalFight; trim routine OnGround, General; constant double : c1, c2; constant int : ci1; begin differential equations x1' = x1 + 2.*x2; x2' = x2 + x1x2; begin algebraic equations x1x2 = x1*x2 + x1'; end model It is important to retain the flexibility of the C language thus the descriptor language is meant to only define certain parts of the definition and implementation of the model class. This way one enigneer provides the model in from of the descriptor language as examplified above and the maintenance enigneer will add all the code to read parameters from files, start/stop/pause the execution of the simulation and how a concrete object gets instatiated. My first though is to either generate two files from the descriptor file: one .h file containing declarations and one .cpp file containing the implementation of certain functions. These then need to be #included at appropriate places [File Aircarft.h] class Aircraft { public: void Aircraft(..); // hand-written constructor void ReadParameters(string &file_name); // hand-written private: /* more hand wirtten boiler-plate code */ /* generate declarations follow */ #include "Aircraft.generated.decl" }; [File Aircraft.cpp] Aircarft::Aircraft(..) { /* hand-written constructer implementation */ } /* more hand-written implementation code */ /* generated implementation code follows */ #include "Aircraft.generated.impl" Any thoughts or suggestions?

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  • How to combine template partial specialization and template argument deduction

    - by KKKoo0
    My understanding is that template argument deduction is only for function templates, but function templates does not allow partial specialization. Is there a way to achieve both? I basically want to achieve a function-like object (can be a functor) with the signature template<class InputIterator1, class InputIterator2, class OutputIterator, int distribution> void GetQuantity(InputIterator1 frist1, InputIterator1 last1, InputIterator2 first2, OutputIterator result, double supply, double limit); Depending on the value of distribution, I want to have a couple of specializations of this template. And when I call this function,I basically do not want to specify all the type parameters, because they are many of them (and thus I need argument deduction)!

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  • Any way to get TStringList.CommaText to not escape commas with quotes?

    - by Mason Wheeler
    I'm doing some work with code generation, and one of the things I need to do is create a function call where one of the parameters is a function call, like so: result := Func1(x, y, Func2(a, b, c)); TStringList.CommaText is very useful for generating the parameter lists, but when I traverse the tree to build the outer function call, what I end up with looks like this: result := Func1(x, y, "Func2(a, b, c)"); It's quoting the third argument because it contains commas, and that produced invalid code. But I can't do something simplistic like StringReplace all double quotes with empty strings, because it's quite possible that a function argument could be a string with double quotes inside. Is there any way to make it just not escape the lines that contain commas?

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  • bin_at in dlmalloc

    - by chunhui
    In glibc malloc.c or dlmalloc It said "repositioning tricks"As in blew, and use this trick in bin_at. bins is a array,the space is allocated when av(struct malloc_state) is allocated.doesn't it? the sizeof(bin[i]) is less then sizeof(struct malloc_chunk*)? Who can describe this trick for me? I can't understand the bin_at macro.why they get the bins address use this method?how it works? Very thanks,and sorry for my poor English. /* To simplify use in double-linked lists, each bin header acts as a malloc_chunk. This avoids special-casing for headers. But to conserve space and improve locality, we allocate only the fd/bk pointers of bins, and then use repositioning tricks to treat these as the fields of a malloc_chunk*. */ typedef struct malloc_chunk* mbinptr; /* addressing -- note that bin_at(0) does not exist */ #define bin_at(m, i) \ (mbinptr) (((char *) &((m)->bins[((i) - 1) * 2])) \ - offsetof (struct malloc_chunk, fd)) The malloc_chunk struct like this: struct malloc_chunk { INTERNAL_SIZE_T prev_size; /* Size of previous chunk (if free). */ INTERNAL_SIZE_T size; /* Size in bytes, including overhead. */ struct malloc_chunk* fd; /* double links -- used only if free. */ struct malloc_chunk* bk; /* Only used for large blocks: pointer to next larger size. */ struct malloc_chunk* fd_nextsize; /* double links -- used only if free. */ struct malloc_chunk* bk_nextsize; }; And the bin type like this: typedef struct malloc_chunk* mbinptr; struct malloc_state { /* Serialize access. */ mutex_t mutex; /* Flags (formerly in max_fast). */ int flags; #if THREAD_STATS /* Statistics for locking. Only used if THREAD_STATS is defined. */ long stat_lock_direct, stat_lock_loop, stat_lock_wait; #endif /* Fastbins */ mfastbinptr fastbinsY[NFASTBINS]; /* Base of the topmost chunk -- not otherwise kept in a bin */ mchunkptr top; /* The remainder from the most recent split of a small request */ mchunkptr last_remainder; /* Normal bins packed as described above */ mchunkptr bins[NBINS * 2 - 2]; /* Bitmap of bins */ unsigned int binmap[BINMAPSIZE]; /* Linked list */ struct malloc_state *next; #ifdef PER_THREAD /* Linked list for free arenas. */ struct malloc_state *next_free; #endif /* Memory allocated from the system in this arena. */ INTERNAL_SIZE_T system_mem; INTERNAL_SIZE_T max_system_mem; };

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  • Memory in Eclipse

    - by user247866
    I'm getting the java.lang.OutOfMemoryError exception in Eclipse. I know that Eclipse by default uses heap size of 256M. I'm trying to increase it but nothing happens. For example: eclipse -vmargs -Xmx16g -XX:PermSize=2g -XX:MaxPermSize=2g I also tried different settings, using only the -Xmx option, using different cases of g, G, m, M, different memory sizes, but nothing helps. Does not matter which params I specify, the heap exception is thrown at the same time, so I assume there's something I'm doing wrong that Eclipse ignores the -Xmx parameter. I'm using a 32GB RAM machine and trying to execute something very simple such as: double[][] a = new double[15000][15000]; It only works when I reduce the array size to something around 10000 on 10000. I'm working on Linux and using the top command I can see how much memory the Java process is consuming; it's less than 2%. Thanks!

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  • jQuery / jqgrid / Editing form events

    - by MiBol
    I'm working with the jqGrid and I want to know if exists an event to read a double click in the Editing Form? Has example: I have a grid with ColumnA and ColumnB. I want read the event when the user perform a double click under ColumnB (In the Editing Form). Thanks! I found the solution of my problem ^^ Here is the code, to this example I use the alert "TEST!!!"... [Thanks to Oleg to wake up my mind :P] In the colModel { name: 'Total_uploads', index: 'Total_uploads', width: '100', editable: true, edittype: 'text', editoptions: { size: 10, maxlength: '20', dataInit: function (el) { $(el).click(function () { alert("TEST!!!"); }); } }, editrules: { required: true }, formoptions: { label: 'Total uploads: ', elmsuffix: '&nbsp;&nbsp; <span style="color : #0C66BE; font-family: Calibri">(*)</span>' } }

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  • Help with complex sql query

    - by eugeneK
    To make story short, i'm building self-learning banner management system. Users will be able to insert these banners to their site when banners will be shown based on sales/impressions ratio. I have 4 tables Banners bannerID int bannerImage varchar.... SmartBanners smartBannerID int smartBannerArrayID int bannerID int impressionsCount int visibility tinyint (percents) SmartBannerArrays smartBannerArrayID int userID int Statistics bannerID int saleAmountPerDay decimal... Each night i need to generate new "visibility" for each SmartBanner based on whole SmartBannerArray that same user has. So i need to get sum of impressions and sales for each bannerID in SmartBannerArray. All comes to my mind is to use double cursor, one will loop thought SmartBannerArrays get needed values for sum of impressions and sales and then inner loop which will access each SmartBanner and change it's "visibility" percentage based on (sales/impressions)/(sumOfSales/sumOfImpressions)*100 Hope you get the picture... Is there any other way to design better tables or not to use double cursor to avoid server overload ?

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  • What is the equivalent of <composite-element> in Castle ActiveRecord?

    - by Daniel T.
    I have a TrackLog that has a collection of TrackPoints: public class TrackLog { public string Name { get; set; } public ISet<TrackPoint> TrackPoints { get; set; } } public class TrackPoint { public DateTime Timestamp { get; set; } public double Latitude { get; set; } public double Longitude { get; set; } } I'd like to map the track points as a collection of components, as this makes the most sense. According to the book NHibernate in Action, on page 187: Collections of components are mapped similarily to other collections of value type instances. The only difference is the use of <composite-element> in place of the familiar <element> tag. How would I do this using Castle ActiveRecord attributes?

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  • How do you implement position-sensitive zooming inside a JScrollPane?

    - by tucuxi
    I am trying to implement position-sensitive zooming inside a JScrollPane. The JScrollPane contains a component with a customized 'paint' that will draw itself inside whatever space it is allocated - so zooming is as easy as using a MouseWheelListener that resizes the inner component as required. But I also want zooming into (or out of) a point to keep that point as central as possible within the resulting zoomed-in (or -out) view (this is what I refer to as 'position-sensitive' zooming), similar to how zooming works in google maps. I am sure this has been done many times before - does anybody know the "right" way to do it under Java Swing?. Would it be better to play with Graphic2D's transformations instead of using JScrollPanes? Sample code follows: package test; import java.awt.*; import java.awt.event.*; import java.awt.geom.*; import javax.swing.*; public class FPanel extends javax.swing.JPanel { private Dimension preferredSize = new Dimension(400, 400); private Rectangle2D[] rects = new Rectangle2D[50]; public static void main(String[] args) { JFrame jf = new JFrame("test"); jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); jf.setSize(400, 400); jf.add(new JScrollPane(new FPanel())); jf.setVisible(true); } public FPanel() { // generate rectangles with pseudo-random coords for (int i=0; i<rects.length; i++) { rects[i] = new Rectangle2D.Double( Math.random()*.8, Math.random()*.8, Math.random()*.2, Math.random()*.2); } // mouse listener to detect scrollwheel events addMouseWheelListener(new MouseWheelListener() { public void mouseWheelMoved(MouseWheelEvent e) { updatePreferredSize(e.getWheelRotation(), e.getPoint()); } }); } private void updatePreferredSize(int n, Point p) { double d = (double) n * 1.08; d = (n > 0) ? 1 / d : -d; int w = (int) (getWidth() * d); int h = (int) (getHeight() * d); preferredSize.setSize(w, h); getParent().doLayout(); // Question: how do I keep 'p' centered in the resulting view? } public Dimension getPreferredSize() { return preferredSize; } private Rectangle2D r = new Rectangle2D.Float(); public void paint(Graphics g) { super.paint(g); g.setColor(Color.red); int w = getWidth(); int h = getHeight(); for (Rectangle2D rect : rects) { r.setRect(rect.getX() * w, rect.getY() * h, rect.getWidth() * w, rect.getHeight() * h); ((Graphics2D)g).draw(r); } } }

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  • MySQL - how long to create an index?

    - by user293594
    Can anyone tell me how adding a key scales in MySQL? I have 500,000,000 rows in a database, trans, with columns i (INT UNSIGNED), j (INT UNSIGNED), nu (DOUBLE), A (DOUBLE). I try to index a column, e.g. ALTER TABLE trans ADD KEY idx_A (A); and I wait. For a table of 14,000,000 rows it took about 2 minutes to execute on my MacBook Pro, but for the whole half a billion, it's taking 15hrs and counting. Am I doing something wrong, or am I just being naive about how indexing a database scales with the number of rows?

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  • Declarative JDOQL vs Single-String JDOQL : performance

    - by DrDro
    When querying with JDOQL is there a performance difference between using the declarative version and the Single-String version: Example from the JDOQL doc: //Declarative JDOQL : Query q = pm.newQuery(org.jpox.Person.class, "lastName == \"Jones\" && age < age_limit"); q.declareParameters("double age_limit"); List results = (List)q.execute(20.0); //Single-String JDOQL : Query q = pm.newQuery("SELECT FROM org.jpox.Person WHERE lastName == \"Jones\"" + " && age < :age_limit PARAMETERS double age_limit"); List results = (List)q.execute(20.0); Other then performance, are there any reasons for which one is better to use then the other or is it just about the one with which we feel more comfortable.

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  • nhibernate fatal error

    - by Afif Lamloumi
    i have an error ( System.InvalidCastException: Unable to cast object of type 'AccountProxy' to type 'System.String'.) when i did this code i mapped the tables( Account,AccountString,EventData,...) of the the database opengts ( open source) i have this error when i called a function from EventData.cs IQuery query = session.CreateQuery("FROM Eventdata"); IList pets = query.List(); return pets; the Stack Trace: [InvalidCastException: Impossible d'effectuer un cast d'un objet de type 'AccountProxy' en type 'System.String'.] (Object , Object[] , SetterCallback ) +431 NHibernate.Bytecode.Lightweight.AccessOptimizer.SetPropertyValues(Object target, Object[] values) +20 NHibernate.Tuple.Component.PocoComponentTuplizer.SetPropertyValues(Object component, Object[] values) +49 NHibernate.Type.ComponentType.SetPropertyValues(Object component, Object[] values, EntityMode entityMode) +34 NHibernate.Type.ComponentType.ResolveIdentifier(Object value, ISessionImplementor session, Object owner) +150 NHibernate.Type.ComponentType.NullSafeGet(IDataReader rs, String[] names, ISessionImplementor session, Object owner) +42 NHibernate.Loader.Loader.GetKeyFromResultSet(Int32 i, IEntityPersister persister, Object id, IDataReader rs, ISessionImplementor session) +93 NHibernate.Loader.Loader.GetRowFromResultSet(IDataReader resultSet, ISessionImplementor session, QueryParameters queryParameters, LockMode[] lockModeArray, EntityKey optionalObjectKey, IList hydratedObjects, EntityKey[] keys, Boolean returnProxies) +92 NHibernate.Loader.Loader.DoQuery(ISessionImplementor session, QueryParameters queryParameters, Boolean returnProxies) +675 NHibernate.Loader.Loader.DoQueryAndInitializeNonLazyCollections(ISessionImplementor session, QueryParameters queryParameters, Boolean returnProxies) +129 NHibernate.Loader.Loader.DoList(ISessionImplementor session, QueryParameters queryParameters) +116 [GenericADOException: could not execute query [ select eventdata0_.deviceID as deviceID5_, eventdata0_.timestamp as timestamp5_, eventdata0_.statusCode as statusCode5_, eventdata0_.accountID as accountID5_, eventdata0_.latitude as latitude5_, eventdata0_.longitude as longitude5_, eventdata0_.gpsAge as gpsAge5_, eventdata0_.speedKPH as speedKPH5_, eventdata0_.heading as heading5_, eventdata0_.altitude as altitude5_, eventdata0_.transportID as transpo11_5_, eventdata0_.inputMask as inputMask5_, eventdata0_.outputMask as outputMask5_, eventdata0_.address as address5_, eventdata0_.DataSource as DataSource5_, eventdata0_.rawdata as rawdata5_, eventdata0_.distanceKM as distanceKM5_, eventdata0_.odometerKM as odometerKM5_, eventdata0_.geozoneIndex as geozone19_5_, eventdata0_.geozoneID as geozoneID5_, eventdata0_.creationTime as creatio21_5_ from eventdata eventdata0_ ] [SQL: select eventdata0_.deviceID as deviceID5_, eventdata0_.timestamp as timestamp5_, eventdata0_.statusCode as statusCode5_, eventdata0_.accountID as accountID5_, eventdata0_.latitude as latitude5_, eventdata0_.longitude as longitude5_, eventdata0_.gpsAge as gpsAge5_, eventdata0_.speedKPH as speedKPH5_, eventdata0_.heading as heading5_, eventdata0_.altitude as altitude5_, eventdata0_.transportID as transpo11_5_, eventdata0_.inputMask as inputMask5_, eventdata0_.outputMask as outputMask5_, eventdata0_.address as address5_, eventdata0_.DataSource as DataSource5_, eventdata0_.rawdata as rawdata5_, eventdata0_.distanceKM as distanceKM5_, eventdata0_.odometerKM as odometerKM5_, eventdata0_.geozoneIndex as geozone19_5_, eventdata0_.geozoneID as geozoneID5_, eventdata0_.creationTime as creatio21_5_ from eventdata eventdata0_]] NHibernate.Loader.Loader.DoList(ISessionImplementor session, QueryParameters queryParameters) +213 NHibernate.Loader.Loader.ListIgnoreQueryCache(ISessionImplementor session, QueryParameters queryParameters) +18 NHibernate.Loader.Loader.List(ISessionImplementor session, QueryParameters queryParameters, ISet`1 querySpaces, IType[] resultTypes) +79 NHibernate.Hql.Ast.ANTLR.Loader.QueryLoader.List(ISessionImplementor session, QueryParameters queryParameters) +51 NHibernate.Hql.Ast.ANTLR.QueryTranslatorImpl.List(ISessionImplementor session, QueryParameters queryParameters) +231 NHibernate.Engine.Query.HQLQueryPlan.PerformList(QueryParameters queryParameters, ISessionImplementor session, IList results) +369 NHibernate.Impl.SessionImpl.List(String query, QueryParameters queryParameters, IList results) +317 NHibernate.Impl.SessionImpl.List(String query, QueryParameters parameters) +282 NHibernate.Impl.QueryImpl.List() +163 DATA1.EventdataExtensions.GetEventdata() in C:\Users\HP\Desktop\our_project\DATA1\Queries\Eventdata.cs:33 MvcApplication7.Controllers.HistoriqueController.Index() in C:\Users\HP\Desktop\our_project\MvcApplication7\Controllers\HistoriqueController.cs:17 lambda_method(Closure , ControllerBase , Object[] ) +62 System.Web.Mvc.ActionMethodDispatcher.Execute(ControllerBase controller, Object[] parameters) +17 System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters) +208 System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +27 System.Web.Mvc.<>c__DisplayClass15.<InvokeActionMethodWithFilters>b__12() +55 System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation) +263 System.Web.Mvc.<>c__DisplayClass17.<InvokeActionMethodWithFilters>b__14() +19 System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodWithFilters(ControllerContext controllerContext, IList`1 filters, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +191 System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName) +343 System.Web.Mvc.Controller.ExecuteCore() +116 System.Web.Mvc.ControllerBase.Execute(RequestContext requestContext) +97 System.Web.Mvc.ControllerBase.System.Web.Mvc.IController.Execute(RequestContext requestContext) +10 System.Web.Mvc.<>c__DisplayClassb.<BeginProcessRequest>b__5() +37 System.Web.Mvc.Async.<>c__DisplayClass1.<MakeVoidDelegate>b__0() +21 System.Web.Mvc.Async.<>c__DisplayClass8`1.<BeginSynchronous>b__7(IAsyncResult _) +12 System.Web.Mvc.Async.WrappedAsyncResult`1.End() +62 System.Web.Mvc.<>c__DisplayClasse.<EndProcessRequest>b__d() +50 System.Web.Mvc.SecurityUtil.<GetCallInAppTrustThunk>b__0(Action f) +7 System.Web.Mvc.SecurityUtil.ProcessInApplicationTrust(Action action) +22 System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +60 System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +9 System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +8841105 System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +184 Any suggestions? how can correct this error Data entity class (outtake from comment): public class MyClass { public virtual string DeviceID { get; set; } public virtual int Timestamp { get; set; } public virtual string Account { get; set; } public virtual int StatusCode { get; set; } public virtual double Latitude { get; set; } public virtual double Longitude { get; set; } public virtual int GpsAge { get; set; } public virtual double SpeedKPH { get; set; } public virtual double Heading { get; set; } public override bool Equals(object obj) { return true; } public override int GetHashCode() { return 0; } }

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  • What can be done to speed up synchronous WCF calls?

    - by Dimitri C.
    My performance measurements of synchronous WCF calls from within a Silverlight application showed I can make 7 calls/s on a localhost connection, which is very slow. Can this be speeded up, or is this normal? This is my test code: const UInt32 nrCalls = 100; ICalculator calculator = new CalculatorClient(); // took over from the MSDN calculator example for (double i = 0; i < nrCalls; ++i) { var call = calculator.BeginSubtract(i + 1, 1, null, null); call.AsyncWaitHandle.WaitOne(); double result = calculator.EndSubtract(call); } Remarks: CPU load is almost 0%. Apparently, the WCF module is waiting for something. I tested this both on Firefox 3.6 and Internet Explorer 7. I'm using Silverlight v3.0

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  • Java Regex for matching quoted string with escaped quotes

    - by kayahr
    I know there are already many questions like mine but I found no answer which works in Java. So I write a new question. I have text files with content like this: key1 = "This is a \"test\" text with escapes using '\\' characters"; key2 = 'It must work with \'single\' quotes and "double" quotes'; I need a regular expression which matches the values in the double-quotes (or single-quotes). This regular expression must support the escaped quotes and escaped backslashes. The regular expression must work with Java standard Pattern/Matcher classes.

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