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  • Should we use <label> for every <input>?

    - by metal-gear-solid
    Should we use <label> for every input? , even for submit button and keep hidden thorough css if we don't want to show label. or no need of label for submit button? .hide {display:none} <fieldset> <legend>Search</legend> <label for="Search">Search...</label> <input value="" id="Search" name="Search"> <label for="Submit" class="hide">Submit</label> <input type="submit" value="Go!" name="submit" id="submit"> </fieldset> or we should use like this (no label for submit) <fieldset> <legend>Search</legend> <label for="Search">Search...</label> <input value="" id="Search" name="Search"> <input type="submit" value="Go!" name="submit" > </fieldset>

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  • Filtering two arrays to avoid Inf/NaN values

    - by Gacek
    I have two arrays of doubles of the same size, containg X and Y values for some plots. I need to create some kind of protection against Inf/NaN values. I need to find all that pairs of values (X, Y) for which both, X and Y are not Inf nor NaN If I have one array, I can do it using lambdas: var filteredValues = someValues.Where(d=> !(double.IsNaN(d) || double.IsInfinity(d))).ToList(); Now, for two arrays I use following loop: List<double> filteredX=new List<double>(); List<double> filteredX=new List<double>(); for(int i=0;i<XValues.Count;i++) { if(!double.IsNan(XValues[i]) && !double.IsInfinity(XValues[i]) && !double.IsNan(YValues[i]) && !double.IsInfinity(YValues[i]) ) { filteredX.Add(XValues[i]); filteredY.Add(YValues[i]); } } Is there any way of filtering two arrays at the same time using LINQ/Lambdas, as it was done for single array?

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  • I need to modify a program to use arrays and a method call. Should I modify the running file, the data collection file, or both?

    - by g3n3rallyl0st
    I have to have multiple classes for this program. The problem is, I don't fully understand arrays and how they work, so I'm a little lost. I will post my program I have written thus far so you can see what I'm working with, but I don't expect anyone to DO my assignment for me. I just need to know where to start and I'll try to go from there. I think I need to use a double array since I will be working with decimals since it deals with money, and my method call needs to calculate total price for all items entered by the user. Please help: RUNNING FILE package inventory2; import java.util.Scanner; public class RunApp { public static void main(String[] args) { Scanner input = new Scanner( System.in ); DataCollection theProduct = new DataCollection(); String Name = ""; double pNumber = 0.0; double Units = 0.0; double Price = 0.0; while(true) { System.out.print("Enter Product Name: "); Name = input.next(); theProduct.setName(Name); if (Name.equalsIgnoreCase("stop")) { return; } System.out.print("Enter Product Number: "); pNumber = input.nextDouble(); theProduct.setpNumber(pNumber); System.out.print("Enter How Many Units in Stock: "); Units = input.nextDouble(); theProduct.setUnits(Units); System.out.print("Enter Price Per Unit: "); Price = input.nextDouble(); theProduct.setPrice(Price); System.out.print("\n Product Name: " + theProduct.getName()); System.out.print("\n Product Number: " + theProduct.getpNumber()); System.out.print("\n Amount of Units in Stock: " + theProduct.getUnits()); System.out.print("\n Price per Unit: " + theProduct.getPrice() + "\n\n"); System.out.printf("\n Total cost for %s in stock: $%.2f\n\n\n", theProduct.getName(), theProduct.calculatePrice()); } } } DATA COLLECTION FILE package inventory2; public class DataCollection { String productName; double productNumber, unitsInStock, unitPrice, totalPrice; public DataCollection() { productName = ""; productNumber = 0.0; unitsInStock = 0.0; unitPrice = 0.0; } //setter methods public void setName(String name) { productName = name; } public void setpNumber(double pNumber) { productNumber = pNumber; } public void setUnits(double units) { unitsInStock = units; } public void setPrice(double price) { unitPrice = price; } //getter methods public String getName() { return productName; } public double getpNumber() { return productNumber; } public double getUnits() { return unitsInStock; } public double getPrice() { return unitPrice; } public double calculatePrice() { return (unitsInStock * unitPrice); } }

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  • Need to interface to a C++ DLL

    - by Pedro
    Hi, I need to call a C++ API from C#. I have been able to call the API, but the char[] parameters do not seem to be marshalling correctly. Here's the C++ signature: Create2ptModel(double modelPowers[2], double modelDacs[2], int pclRange[2], double targetPowers[32], double *dacAdjustFactor, unsigned short powerRampFactors[32], BOOL bPCLDacAdjusted[32], char calibrationModel[32], char errMsg[1024]) and this is how I am trying to call it from C# [DllImport("AlgorithmsLib.dll", EntryPoint = "_Create2ptModel@36", ExactSpelling = true, CallingConvention = CallingConvention.StdCall, CharSet = CharSet.Auto)] private static extern AlgorithmStatus Create2ptModel( double[] modelPowers, double[] modelDacs, int[] pclRange, double[] targetPowers, ref double dacAdjustFactor, ushort[] powerRampFactors, bool[] bPCLDacAdjusted, /**/char[] calibrationModel, char[] errMsg/**/); Any idea of how I can marshall it correctly? Thanks in advance!

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  • Keep getting error class, interface, or enum expected

    - by user1746605
    I can't see the problem with this short class. I get 8 class, interface, or enum expected errors. Thanks public class BankAccount { public BankAccount { private double balance = 0; } public BankAccount(double balanceIn) { private double balance = balanceIn; } public double checkBalance { return balance; } public void deposit(double amount) { if(amount > 0) balance += amount; } public void withdraw(double amount) { if(amount <= balance) balance -= amount; } }

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  • reference function from another function

    - by JohnWong
    I forgot how to reference another function into a function in C++? In python it is declare as a class so that I can use it. double footInches(double foot) { double inches = (1.0/12.00) * foot; return inches; } double inchMeter(double inch) { double meter = 39.37 * (footInches(inches)); return meter; } I want to reference footInches in inchMeter.

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  • Declaring two large 2d arrays gives segmentation fault.

    - by pfdevil
    Hello, i'm trying to declare and allocate memory for two 2d-arrays. However when trying to assign values to itemFeatureQ[39][16816] I get a segmentation vault. I can't understand it since I have 2GB of RAM and only using 19MB on the heap. Here is the code; double** reserveMemory(int rows, int columns) { double **array; int i; array = (double**) malloc(rows * sizeof(double *)); if(array == NULL) { fprintf(stderr, "out of memory\n"); return NULL; } for(i = 0; i < rows; i++) { array[i] = (double*) malloc(columns * sizeof(double *)); if(array == NULL) { fprintf(stderr, "out of memory\n"); return NULL; } } return array; } void populateUserFeatureP(double **userFeatureP) { int x,y; for(x = 0; x < CUSTOMERS; x++) { for(y = 0; y < FEATURES; y++) { userFeatureP[x][y] = 0; } } } void populateItemFeatureQ(double **itemFeatureQ) { int x,y; for(x = 0; x < FEATURES; x++) { for(y = 0; y < MOVIES; y++) { printf("(%d,%d)\n", x, y); itemFeatureQ[x][y] = 0; } } } int main(int argc, char *argv[]){ double **userFeatureP = reserveMemory(480189, 40); double **itemFeatureQ = reserveMemory(40, 17770); populateItemFeatureQ(itemFeatureQ); populateUserFeatureP(userFeatureP); return 0; }

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  • 2 dimensional arrays passed to a function in c++

    - by John Marcus
    I'm working on doing calculations in a two dimensional array but keep getting a nasty error. i call the function by : if(checkArray(array)) and try to pass it in like this: bool checkArray(double array[][10]) //or double *array[][10] to no avail the error is error: cannot convert ‘double ()[(((unsigned int)(((int)n) + -0x00000000000000001)) + 1)]’ to ‘double’ for argument ‘1’ to ‘bool checkArray(double*)’ code snippet //array declaration int n = 10; double array[n][n]; //function call to pass in array while(f != 25) { cout<<endl; cout<<endl; if(checkArray(array)) //this is the line of the error { cout<<"EXIT EXIT EXIT"<<endl; } f++; } //function declaration bool checkArray(double *array)//, double newArray[][10]) { double length = sizeof(array); for(int i = 0; i < length; i++) for(int j = 0; j < length;j++) { double temp = array[i][j]; } }

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  • Need help with java map and javabean

    - by techoverflow
    Hi folks, I have a nested map: Map<Integer, Map<Integer, Double>> areaPrices = new HashMap<Integer, Map<Integer, Double>>(); and this map is populated using the code: while(oResult.next()) { Integer areaCode = new Integer(oResult.getString("AREA_CODE")); Map<Integer, Double> zonePrices = areaPrices.get(areaCode); if(zonePrices==null) { zonePrices = new HashMap<Integer, Double>(); areaPrices.put(areaCode, zonePrices); } Integer zoneCode = new Integer(oResult.getString("ZONE_CODE")); Double value = new Double(oResult.getString("ZONE_VALUE")); zonePrices.put(zoneCode, value); myBean.setZoneValues(areaPrices); } I want to use the value of this Map in another method of the same class. For that I have a bean. How do I populate it on the bean, so that I can get the ZONE_VALUE in this other method In my bean I added one new field as: private Map<Integer, Map<Integer, Double>> zoneValues; with getter and setter as: public Map<Integer, Map<Integer, Double>> getZoneValues() { return zoneValues; } public void setZoneValues(Map<Integer, Map<Integer, Double>> areaPrices) { this.zoneValues = areaPrices; } What I am looking for to do in the other method is something like this: Double value = myBean.get(areaCode).get(zoneCode); How do I make it happen :(

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  • Using template specialization in C++

    - by user550413
    How can I write a function using template specialization that has 2 different input types and an output type: template <class input1, class input2, class output> and return the sum of the 2 numbers (integers/doubles). However, if I get 2 integers I want to return an integer type but for any other combinations of integer and double I'll always return double. I am trying to do that without using directly the '+' operator but having the next functions instead: double add_double_double(double a, double b) {return (a+b);} double add_int_double(int a, double b) {return ((double)(a)+b);} int add_int_int(int a, int b) {return (a+b);}

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  • "...redeclared as different kind of symbol"?

    - by CodeNewb
    #include <stdio.h> #include <math.h> double integrateF(double low, double high) { double low = 0; double high = 20; double delta_x=0; double x, ans; double s = 1/2*exp((-x*x)/2); for(x=low;x<=high;x++) delta_x = x+delta_x; ans = delta_x*s; return ans; } It says that low and high are "redeclared as different type of symbol" and I don't know what that means. Basically, all I'm doing here (READ: trying) is integrating from low (which I set to 0) to high (20) to find the Riemann sum. The for loop looks kinda trippy too...I'm so lost.

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  • How to optimize method's that track metrics in 3rd party application?

    - by WulfgarPro
    Hi, I have two listboxes that keep updated lists of various objects roaming in a 3rd party application. When a user selects an object from a listbox, an event handler is fired, calling a method that gathers various metrics belonging to that object from the 3rd party application for displaying in a set of textboxes. This is slow! I am not sure how to optimize this functionality to facilitate greater speeds.. private void lsbUavs_SelectedIndexChanged(object sender, EventArgs e) { if (_ourSelectedUavFromListBox != null) { UtilStkScenario.ChangeUavColourOnScenario(_ourSelectedUavFromListBox.UavName, false); } if (lsbUavs.SelectedItem != null) { Uav ourUav = UtilStkScenario.FindUavFromScenarioBasedOnName(lsbUavs.SelectedItem.ToString()); hsbThrottle.Value = (int)ourUav.ThrottleValue; UtilStkScenario.ChangeUavColourOnScenario(ourUav.UavName, true); _ourSelectedUavFromListBox = ourUav; // we don't want this thread spawning many times if (tUpdateMetricInformationInTabControl != null) { if (tUpdateMetricInformationInTabControl.IsAlive) { tUpdateMetricInformationInTabControl.Abort(); } } tUpdateMetricInformationInTabControl = new Thread(UpdateMetricInformationInTabControl); tUpdateMetricInformationInTabControl.Name = "UpdateMetricInformationInTabControlUavs"; tUpdateMetricInformationInTabControl.IsBackground = true; tUpdateMetricInformationInTabControl.Start(lsbUavs); } } delegate string GetNameOfListItem(ListBox listboxId); delegate void SetTextBoxValue(TextBox textBoxId, string valueToSet); private void UpdateMetricInformationInTabControl(object listBoxToUpdate) { ListBox theListBoxToUpdate = (ListBox)listBoxToUpdate; GetNameOfListItem dGetNameOfListItem = new GetNameOfListItem(GetNameOfSelectedListItem); SetTextBoxValue dSetTextBoxValue = new SetTextBoxValue(SetNamedTextBoxValue); try { foreach (KeyValuePair<string, IAgStkObject> entity in UtilStkScenario._totalListOfAllStkObjects) { if (entity.Key.ToString() == (string)theListBoxToUpdate.Invoke(dGetNameOfListItem, theListBoxToUpdate)) { while ((string)theListBoxToUpdate.Invoke(dGetNameOfListItem, theListBoxToUpdate) == entity.Key.ToString()) { if (theListBoxToUpdate.Name == "lsbEntities") { double[] latLonAndAltOfEntity = UtilStkScenario.FindMetricsOfStkObjectOnScenario(UtilStkScenario._stkObjectRoot.CurrentTime, entity.Value); SetEntityOrUavMetricValuesInTextBoxes(dSetTextBoxValue, "Entity", entity.Key, "", "", "", "", latLonAndAltOfEntity[4].ToString(), latLonAndAltOfEntity[3].ToString()); } else if (theListBoxToUpdate.Name == "lsbUavs") { double[] latLonAndAltOfEntity = UtilStkScenario.FindMetricsOfStkObjectOnScenario(UtilStkScenario._stkObjectRoot.CurrentTime, entity.Value); SetEntityOrUavMetricValuesInTextBoxes(dSetTextBoxValue, "UAV", entity.Key, entity.Value.ClassName.ToString(), latLonAndAltOfEntity[0].ToString(), latLonAndAltOfEntity[1].ToString(), latLonAndAltOfEntity[2].ToString(), latLonAndAltOfEntity[4].ToString(), latLonAndAltOfEntity[3].ToString()); } } } } } catch (Exception e) { // selected entity was deleted(end-of-life) in STK - remove LLA information from GUI if (theListBoxToUpdate.Name == "lsbEntities") { SetEntityOrUavMetricValuesInTextBoxes(dSetTextBoxValue, "Entity", "", "", "", "", "", "", ""); UtilLog.Log(e.Message.ToString(), e.GetType().ToString(), "UpdateMetricInformationInTabControl", UtilLog.logWriter); } else if (theListBoxToUpdate.Name == "lsbUavs") { SetEntityOrUavMetricValuesInTextBoxes(dSetTextBoxValue, "UAV", "", "", "", "", "", "", ""); UtilLog.Log(e.Message.ToString(), e.GetType().ToString(), "UpdateMetricInformationInTabControl", UtilLog.logWriter); } } } internal static double[] FindMetricsOfStkObjectOnScenario(object timeToFindMetricState, IAgStkObject stkObject) { double[] stkObjectMetrics = null; try { stkObjectMetrics = new double[5]; object latOfStkObject, lonOfStkObject; double altOfStkObject, headingOfStkObject, velocityOfStkObject; IAgProvideSpatialInfo spatial = stkObject as IAgProvideSpatialInfo; IAgVeSpatialInfo spatialInfo = spatial.GetSpatialInfo(false); IAgSpatialState spatialState = spatialInfo.GetState(timeToFindMetricState); spatialState.FixedPosition.QueryPlanetodetic(out latOfStkObject, out lonOfStkObject, out altOfStkObject); double[] stkObjectheadingAndVelocity = FindHeadingAndVelocityOfStkObjectFromScenario(stkObject.InstanceName); headingOfStkObject = stkObjectheadingAndVelocity[0]; velocityOfStkObject = stkObjectheadingAndVelocity[1]; stkObjectMetrics[0] = (double)latOfStkObject; stkObjectMetrics[1] = (double)lonOfStkObject; stkObjectMetrics[2] = altOfStkObject; stkObjectMetrics[3] = headingOfStkObject; stkObjectMetrics[4] = velocityOfStkObject; } catch (Exception e) { UtilLog.Log(e.Message.ToString(), e.GetType().ToString(), "FindMetricsOfStkObjectOnScenario", UtilLog.logWriter); } return stkObjectMetrics; } private static double[] FindHeadingAndVelocityOfStkObjectFromScenario(string stkObjectName) { double[] stkObjectHeadingAndVelocity = new double[2]; IAgStkObject stkUavObject = null; try { string typeOfObject = CheckIfStkObjectIsEntityOrUav(stkObjectName); if (typeOfObject == "UAV") { stkUavObject = _stkObjectRootToIsolateForUavs.CurrentScenario.Children[stkObjectName]; IAgDataProviderGroup group = (IAgDataProviderGroup)stkUavObject.DataProviders["Heading"]; IAgDataProvider provider = (IAgDataProvider)group.Group["Fixed"]; IAgDrResult result = ((IAgDataPrvTimeVar)provider).ExecSingle(_stkObjectRootToIsolateForUavs.CurrentTime); stkObjectHeadingAndVelocity[0] = (double)result.DataSets[1].GetValues().GetValue(0); stkObjectHeadingAndVelocity[1] = (double)result.DataSets[4].GetValues().GetValue(0); } else if (typeOfObject == "Entity") { IAgStkObject stkEntityObject = _stkObjectRootToIsolateForEntities.CurrentScenario.Children[stkObjectName]; IAgDataProviderGroup group = (IAgDataProviderGroup)stkEntityObject.DataProviders["Heading"]; IAgDataProvider provider = (IAgDataProvider)group.Group["Fixed"]; IAgDrResult result = ((IAgDataPrvTimeVar)provider).ExecSingle(_stkObjectRootToIsolateForEntities.CurrentTime); stkObjectHeadingAndVelocity[0] = (double)result.DataSets[1].GetValues().GetValue(0); stkObjectHeadingAndVelocity[1] = (double)result.DataSets[4].GetValues().GetValue(0); } } catch (Exception e) { UtilLog.Log(e.Message.ToString(), e.GetType().ToString(), "FindHeadingAndVelocityOfStkObjectFromScenario", UtilLog.logWriter); } return stkObjectHeadingAndVelocity; } Any help would be really appreciated. From my knowledge, I cant really see any issues with the C#. Maybe it has to do with the methodology I'm using.. maybe some kind of caching mechanism is required - this is not natively available. WulfgarPro

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  • Troubleshooting VC++ DLL in VB.Net

    - by Jolyon
    I'm trying to make a solution in Visual Studio that consists of a VC++ DLL and a VB.Net application. To figure this out, I created a VC++ Class Library project, with the following code (I removed all the junk the wizard creates): mathfuncs.cpp: #include "MathFuncs.h" namespace MathFuncs { double MyMathFuncs::Add(double a, double b) { return a + b; } } mathfuncs.h: using namespace System; namespace MathFuncs { public ref class MyMathFuncs { public: static double Add(double a, double b); }; } This compiles quite happily. I can then add a VC++ console project to the solution, add a reference to the original project for this new project, and call it as follows: test.cpp: using namespace System; int main(array<System::String ^> ^args) { double a = 7.4; int b = 99; Console::WriteLine("a + b = {0}", MathFuncs::MyMathFuncs::Add(a, b)); return 0; } This works just fine, and will build to test.exe and mathsfuncs.dll. However, I want to use a VB.Net project to call the DLL. To do this, I add a VB.Net project to the solution, make it the startup project, and add a reference to the original project. Then, I attempt to use it as follows: MsgBox(MathFuncs.MyMathFuncs.Add(1, 2)) However, when I run this code, it gives me an error: "Could not load file or assembly 'MathFuncsAssembly, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null' or one of its dependencies. An attempt was made to load a program with an incorrect format." Do I need to expose the method somehow? I'm using Visual Studio 2008 Professional.

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  • Semi Fixed-timestep ported to javascript

    - by abernier
    In Gaffer's "Fix Your Timestep!" article, the author explains how to free your physics' loop from the paint one. Here is the final code, written in C: double t = 0.0; const double dt = 0.01; double currentTime = hires_time_in_seconds(); double accumulator = 0.0; State previous; State current; while ( !quit ) { double newTime = time(); double frameTime = newTime - currentTime; if ( frameTime > 0.25 ) frameTime = 0.25; // note: max frame time to avoid spiral of death currentTime = newTime; accumulator += frameTime; while ( accumulator >= dt ) { previousState = currentState; integrate( currentState, t, dt ); t += dt; accumulator -= dt; } const double alpha = accumulator / dt; State state = currentState*alpha + previousState * ( 1.0 - alpha ); render( state ); } I'm trying to implement this in JavaScript but I'm quite confused about the second while loop... Here is what I have for now (simplified): ... (function animLoop(){ ... while (accumulator >= dt) { // While? In a requestAnimation loop? Maybe if? ... } ... // render requestAnimationFrame(animLoop); // stand for the 1st while loop [OK] }()) As you can see, I'm not sure about the while loop inside the requestAnimation one... I thought replacing it with a if but I'm not sure it will be equivalent... Maybe some can help me.

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  • Technique to have screen independent grid based puzzle with sprite animation

    - by Yan Cheng CHEOK
    Hello all, let's say I have a fixed size grid puzzle game (8 x 10). I will be using sprites animation, when the "pieces" in the puzzle is moving from one grid to another grid. I was wondering, what is the technique to have this game being implemented as screen resolution independent. Here is what I plan to do. 1) The data structure coordinate will be represented using double, with 1.0 as max value. // Puzzle grid of 8 x 10 Environment { double width = 0.8; double height = 1.0; } // Location of Sprite at coordinate (1, 1) Sprite { double posX = 0.1; double posY = 0.1; double width = 0.1; double height = 0.1; } // scale = PYSICAL_SCREEN_SIZE drawBitmap ( sprite_image, sprite_image_rect, new Rect(sprite.posX * Scale, sprite.posY * Scale, (sprite.posX + sprite.width) * Scale, (sprite.posY + sprite.Height) * Scale), paint ); 2) A large size sprite image will be used (128x128). As sprite image shall look fine if we scale from large size down to small size, but not vice versa. Besides the above mentioned technique, is there any other consideration I had missed out?

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  • C++ Windows Forms application unhandled exception error when textbox empty

    - by cmorris1441
    I'm building a temperature conversion application in Visual Studio for a C++ course. It's a Windows Forms application and the code that I've written is below. There's other code to of course, but I'm not sure you need it to help me. My problem is, when I run the application if I don't have anything entered into either the txtFahrenheit or txtCelsius2 textboxes I get the following error: "An unhandled exception of type 'System.FormatException' occurred in mscorlib.dll" The application only works right now when a number is entered into both of the textboxes. I was told to try and use this: Double::TryParse() but I'm brand new to C++ and can't figure out how to use it, even after checking the MSDN library. Here's my code: private: System::Void btnFtoC_Click(System::Object^ sender, System::EventArgs^ e) { // Convert the input in the Fahrenheit textbox to a double datatype named fahrenheit for manipulation double fahrenheit = Convert::ToDouble(txtFahrenheit->Text); // Set the result string to F * (5/9) -32 double result = fahrenheit * .5556 - 32; // Set the Celsius text box to display the result string txtCelsius->Text = result.ToString(); } private: System::Void btnCtoF_Click(System::Object^ sender, System::EventArgs^ e) { // Convert the input in the Celsius textbox to a double datatype name celsius for manipulation double celsius = Convert::ToDouble(txtCelsius2->Text); // Set the result2 string to C * (9/5) + 32 double result2 = celsius * 1.8 + 32; // Set the Fahrenheit text box to display the result2 string txtFahrenheit2->Text = result2.ToString(); }

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  • Writing a program in C++ and I need help [migrated]

    - by compscinoob
    So I am a new to this. I am trying to write a program with a function double_product(vector< double a, vector< double b) that computes the scalar product of two vectors. The scalar product is $a_{0}b_{0}+a_{1}b_{1}+...a_{n-1}b_{n-1}$. Here is what I have. It is a mess, but I am trying! #include<iostream> #include<vector> using namespace std; class Scalar_product { public: Scalar_product(vector<double> a, vector<bouble> b); }; double scalar_product(vector<double> a, vector<double> b) { double product = 0; for (int i=0; i <=a.size()-1; i++) for (int i=0; i <=b.size()-1; i++) product = product + (a[i])*(b[i]); return product; } int main() { cout << product << endl; return 0; }

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  • Applications: The Mathematics of Movement, Part 3

    - by TechTwaddle
    Previously: Part 1, Part 2 As promised in the previous post, this post will cover two variations of the marble move program. The first one, Infinite Move, keeps the marble moving towards the click point, rebounding it off the screen edges and changing its direction when the user clicks again. The second version, Finite Move, is the same as first except that the marble does not move forever. It moves towards the click point, rebounds off the screen edges and slowly comes to rest. The amount of time that it moves depends on the distance between the click point and marble. Infinite Move This case is simple (actually both cases are simple). In this case all we need is the direction information which is exactly what the unit vector stores. So when the user clicks, you calculate the unit vector towards the click point and then keep updating the marbles position like crazy. And, of course, there is no stop condition. There’s a little more additional code in the bounds checking conditions. Whenever the marble goes off the screen boundaries, we need to reverse its direction.  Here is the code for mouse up event and UpdatePosition() method, //stores the unit vector double unitX = 0, unitY = 0; double speed = 6; //speed times the unit vector double incrX = 0, incrY = 0; private void Form1_MouseUp(object sender, MouseEventArgs e) {     double x = e.X - marble1.x;     double y = e.Y - marble1.y;     //calculate distance between click point and current marble position     double lenSqrd = x * x + y * y;     double len = Math.Sqrt(lenSqrd);     //unit vector along the same direction (from marble towards click point)     unitX = x / len;     unitY = y / len;     timer1.Enabled = true; } private void UpdatePosition() {     //amount by which to increment marble position     incrX = speed * unitX;     incrY = speed * unitY;     marble1.x += incrX;     marble1.y += incrY;     //check for bounds     if ((int)marble1.x < MinX + marbleWidth / 2)     {         marble1.x = MinX + marbleWidth / 2;         unitX *= -1;     }     else if ((int)marble1.x > (MaxX - marbleWidth / 2))     {         marble1.x = MaxX - marbleWidth / 2;         unitX *= -1;     }     if ((int)marble1.y < MinY + marbleHeight / 2)     {         marble1.y = MinY + marbleHeight / 2;         unitY *= -1;     }     else if ((int)marble1.y > (MaxY - marbleHeight / 2))     {         marble1.y = MaxY - marbleHeight / 2;         unitY *= -1;     } } So whenever the user clicks we calculate the unit vector along that direction and also the amount by which the marble position needs to be incremented. The speed in this case is fixed at 6. You can experiment with different values. And under bounds checking, whenever the marble position goes out of bounds along the x or y direction we reverse the direction of the unit vector along that direction. Here’s a video of it running;   Finite Move The code for finite move is almost exactly same as that of Infinite Move, except for the difference that the speed is not fixed and there is an end condition, so the marble comes to rest after a while. Code follows, //unit vector along the direction of click point double unitX = 0, unitY = 0; //speed of the marble double speed = 0; private void Form1_MouseUp(object sender, MouseEventArgs e) {     double x = 0, y = 0;     double lengthSqrd = 0, length = 0;     x = e.X - marble1.x;     y = e.Y - marble1.y;     lengthSqrd = x * x + y * y;     //length in pixels (between click point and current marble pos)     length = Math.Sqrt(lengthSqrd);     //unit vector along the same direction as vector(x, y)     unitX = x / length;     unitY = y / length;     speed = length / 12;     timer1.Enabled = true; } private void UpdatePosition() {     marble1.x += speed * unitX;     marble1.y += speed * unitY;     //check for bounds     if ((int)marble1.x < MinX + marbleWidth / 2)     {         marble1.x = MinX + marbleWidth / 2;         unitX *= -1;     }     else if ((int)marble1.x > (MaxX - marbleWidth / 2))     {         marble1.x = MaxX - marbleWidth / 2;         unitX *= -1;     }     if ((int)marble1.y < MinY + marbleHeight / 2)     {         marble1.y = MinY + marbleHeight / 2;         unitY *= -1;     }     else if ((int)marble1.y > (MaxY - marbleHeight / 2))     {         marble1.y = MaxY - marbleHeight / 2;         unitY *= -1;     }     //reduce speed by 3% in every loop     speed = speed * 0.97f;     if ((int)speed <= 0)     {         timer1.Enabled = false;     } } So the only difference is that the speed is calculated as a function of length when the mouse up event occurs. Again, this can be experimented with. Bounds checking is same as before. In the update and draw cycle, we reduce the speed by 3% in every cycle. Since speed is calculated as a function of length, speed = length/12, the amount of time it takes speed to reach zero is directly proportional to length. Note that the speed is in ‘pixels per 40ms’ because the timeout value of the timer is 40ms.  The readability can be improved by representing speed in ‘pixels per second’. This would require you to add some more calculations to the code, which I leave out as an exercise. Here’s a video of this second version,

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  • Check if a String is a double or an int?

    - by user69514
    I have a string for a Date in the form mm/dd, and I need to check if either the month or day was entered as a double public Date(String dateStr){ int slash = 0; //check slash is present try{ slash = dateStr.indexOf('/'); }catch(StringIndexOutOfBoundsException e){ error = "Invalid date format: " + dateStr; } //check if month is a number try{ month = Integer.parseInt(dateStr.substring(0, slash)); //day = Integer.parseInt(dateStr.substring(slash + 1, dateStr.length())); } catch(NumberFormatException e){ System.out.println("Invalid format for input string: " + dateStr.substring(0, slash)); } //check if day is a number try{ day = Integer.parseInt(dateStr.substring(slash + 1, dateStr.length())); } catch(NumberFormatException e){ System.out.println("Invalid format for input string: " + dateStr.substring(slash + 1, dateStr.length())); } //check if month was entered as a double }

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  • Any way to remove IEs black border around submit button in active forms?

    - by Magnar
    I am implementing a design that uses custom styled submit-buttons. They are quite simply light grey buttons with a slightly darker outer border: input.button { background: #eee; border: 1px solid #ccc; } This looks just right in Firefox, Safari and Opera. The problem is with Internet Explorer, both 6 and 7. Since the form is the first one on the page, it's counted as the main form - and thus active from the get go. The first submit button in the active form receives a solid black border in IE, to mark it as the main action. If I turn off borders, then the black extra border in IE goes away too. I am looking for a way to keep my normal borders, but remove the outline.

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  • Why we used double and triple pointer in objective-C or C language?

    - by Rajendra Bhole
    Hi, I confused when i want to take single pointer and when should i take double pointer? In following structure what exactly did? struct objc_class { Class isa; Class super_class; const char *name; long version; long info; long instance_size; struct objc_ivar_list *ivars; struct objc_method_list **methodLists; struct objc_cache *cache; struct objc_protocol_list *protocols; }; Why we use the "**methodLists" double pointer. Edited int sqlite3_get_table( sqlite3 *db, const char zSql, char **pazResult, int *pnRow, int *pnColumn, char *pzErrmsg ); In above scenario what will be meaning of triple pointer char **pazResult?

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  • when I click submit it should change the text and update the row something is wrong there

    - by Yousef Altaf
    good morning programers, I have this small code which content a news control panel and I made a submit button there to active or inactive the news row so if I click on this button it should change if it's active it will be inactive it worked but there's something wrong there when I click on item one it updates the last on the table not the first on as it should do. here is the code that I use <?php $getNewsData="select * from news"; $QgetNewsData=$db->query($getNewsData)or die($db->error); $count=mysqli_num_rows($QgetNewsData); while($newsRow = mysqli_fetch_array($QgetNewsData)) { $getActivityStatus=$newsRow['news_activity']; switch($getActivityStatus){ case 1: echo"<input style='color:red; font-weight:bold; background:none; border:0;' name='inactive' type='submit' value='?????' /><input name='inActive' type='hidden' value='".$newsRow['news_id']."'/>"; break; case 0: echo"<input style='color:green; font-weight:bold; background:none; border:0;' name='active' type='submit' value='?????' /><input name='Active' type='hidden' value='".$newsRow['news_id']."'/>"; break;} } if(isset($_POST['inactive'])){ $inActive=$_POST['inActive']; echo $inActive; $updateStatus="UPDATE news SET news_activity=0 WHERE news_id='".$inActive."' "; $QupdateStatus=$db->query($updateStatus)or die($db->error); if($QupdateStatus){ } } if(isset($_POST['active'])){ $Active=$_POST['Active']; echo $Active; $updateStatus="UPDATE news SET news_activity=1 WHERE news_id='".$Active."' "; $QupdateStatus=$db->query($updateStatus)or die($db->error); if($QupdateStatus){ header("Location:CpanelHome.php?id=7"); } } ?> please any idea to solve this problem. Thanks, regards

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  • Is there a reason why a submit button would fail in ie6 using jquery?

    - by kgrad
    I have a form being submit to a servlet, there is a jQuery Datepicker on the page. On some computers using ie6, for some reason the page is crashing on submit. I am getting a 404 error, but only sometimes. I have no idea why this would occur. My theory is that somehow it's bypassing the servlet, or its not loading jquery properly, or... I am at a loss. What are some reasons why this could occur on some computers? The exact version of ie6 is 6.0.2900.2180, on windows XP SP2. How can I test with this specific version?

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  • How RSS feed submitter softwares are able to submit feeds??

    - by Nok Imchen
    Well, recently i bought a software that submits RSS to various RSS directories. Some of the directories, when we visit manually through a internet browser, requires registrations to submit our feed (Most popular example of such directories is feedage dot com) What made me wonder is, the software don't ask any login details while submitting my feed to 'feedage'!!! Now, what i'd like to know is, how the software is able to submit my feed to feedage without loggin in ?? if i can get the procedure then i'm planning to code a php script that will do the work for me from my server using cron job

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