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  • Delete Duplicate records from large csv file C# .Net

    - by Sandhurst
    I have created a solution which read a large csv file currently 20-30 mb in size, I have tried to delete the duplicate rows based on certain column values that the user chooses at run time using the usual technique of finding duplicate rows but its so slow that it seems the program is not working at all. What other technique can be applied to remove duplicate records from a csv file Here's the code, definitely I am doing something wrong DataTable dtCSV = ReadCsv(file, columns); //columns is a list of string List column DataTable dt=RemoveDuplicateRecords(dtCSV, columns); private DataTable RemoveDuplicateRecords(DataTable dtCSV, List<string> columns) { DataView dv = dtCSV.DefaultView; string RowFilter=string.Empty; if(dt==null) dt = dv.ToTable().Clone(); DataRow row = dtCSV.Rows[0]; foreach (DataRow row in dtCSV.Rows) { try { RowFilter = string.Empty; foreach (string column in columns) { string col = column; RowFilter += "[" + col + "]" + "='" + row[col].ToString().Replace("'","''") + "' and "; } RowFilter = RowFilter.Substring(0, RowFilter.Length - 4); dv.RowFilter = RowFilter; DataRow dr = dt.NewRow(); bool result = RowExists(dt, RowFilter); if (!result) { dr.ItemArray = dv.ToTable().Rows[0].ItemArray; dt.Rows.Add(dr); } } catch (Exception ex) { } } return dt; }

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  • Help with my PHP template class

    - by blerh
    I want to separate the output of HTML from my program code in my projects, so I wrote a very simple database class. <?php class Template { private $template; function load($filePath) { if(!$this->template = file_get_contents($filePath)) $this->error('Error: Failed to open <strong>' . $filePath . '</strong>'); } function replace($var, $content) { $this->template = str_replace("{$var}", $content, $this->template); } function display() { echo $this->template; } function error($errorMessage) { die('die() by template class: <strong>' . $errorMessage . '</strong>'); } } ?> The thing I need help with is the display() method. Say for example I use this code: $tplObj = new Template(); $tplObj->load('index.php'); $tplObj->replace('{TITLE}', 'Homepage'); $tplObj->display(); And the index.php file is this: <html> <head> <title>{TITLE}</title> </head> <body> <h1>{TITLE}</h1> <?php if($something) { echo '$something is true'; } else { echo '$something is false'; } ?> </body> </html> I'm just wondering if the PHP code in there would be run? Or would it just be sent to the browser as plaintext? I was using eval() in my template class but I hate that function :P Thanks.

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  • How to convert a printer driver to a stand-alone console application which can generate a printer fi

    - by Thorbjørn Ravn Andersen
    I have a situation where the only way to generate a certain datafile is to print it manually to FILE: under Windows and save it in a file for further processing. I would really like to have a small stand-alone program which embeds this binary printer driver so I can run it from a batch file and have it generate that binary file for me, as we can then fully automate the "save file in Visio, 'print' it and upload it to the final destination and trigger a remote test". Is this possible with a suitable Windows SDK? I am a Java programmer, so I do not know Visual Studio and the possibilities with MSDN - yet! - but I'd appreciate pointers. EDIT: I have the installation files for that printer driver, both 32 and 64 bit. Older versions may include a 16 bit driver. EDIT: The "print to FILE:" functionality is just what was recommended by the documentation. I have played a little bit with using the LPR-protocol to see what it can do. I'd still prefer the "invoke small binary" approach.

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  • is mysql index useful on column 'state' when only doing bit-operations on the column?

    - by Geert-Jan
    I have a lot of domain entities (stored in mysql) which undergo lots of different operations. Each operation is executed from a different program. I need to keep (flow)-state for these entities which I implemented in as a long field 'flowstate' used as a bitset. to query mysql for entities which have undergone a certain operation I do something like: select * from entities where state >> 7 & 1 = 1 Indicating bit 7 (cooresponding to operation 7) has run. (<-- simplified) Anyway, I really didn't pay attention to the performance implications of this setup in the beginning, and I think I'm in a bit of trouble since queries as the above run pretty slow. What I'd like to know: Does an mysql index on 'flowstate' help at all? After all it's not a single value Mysql can quickly find using a binary sort or whatever. If it doesn't, are there any other things I could do to speed things up? . Are there special 'mask-indices' for fields with use-cases as the above? TIA, Geert-jan

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  • not able to Deserialize object

    - by Ravisha
    I am having following peice of code ,where in i am trying to serialize and deserailize object of StringResource class. Please note Resource1.stringXml = its coming from resource file.If i pass strelemet.outerXMl i get the object from Deserialize object ,but if i pass Resource1.stringXml i am getting following exception {"< STRING xmlns='' was not expected."} System.Exception {System.InvalidOperationException} class Program { static void Main(string[] args) { StringResource str = new StringResource(); str.DELETE = "CanDelete"; str.ID= "23342"; XmlElement strelemet = SerializeObjectToXmlNode (str); StringResource strResourceObject = DeSerializeXmlNodeToObject<StringResource>(Resource1.stringXml); Console.ReadLine(); } public static T DeSerializeXmlNodeToObject<T>(string objectNodeOuterXml) { try { TextReader objStringsTextReader = new StringReader(objectNodeOuterXml); XmlSerializer stringResourceSerializer = new XmlSerializer(typeof(T),string.Empty); return (T)stringResourceSerializer.Deserialize(objStringsTextReader); } catch (Exception excep) { return default(T); } } public static XmlElement SerializeObjectToXmlNode(object obj) { using (MemoryStream memoryStream = new MemoryStream()) { try { XmlSerializerNamespaces xmlNameSpace = new XmlSerializerNamespaces(); xmlNameSpace.Add(string.Empty, string.Empty); XmlWriterSettings writerSettings = new XmlWriterSettings(); writerSettings.CloseOutput = false; writerSettings.Encoding = System.Text.Encoding.UTF8; writerSettings.Indent = false; writerSettings.OmitXmlDeclaration = true; XmlWriter writer = XmlWriter.Create(memoryStream, writerSettings); XmlSerializer xmlserializer = new XmlSerializer(obj.GetType()); xmlserializer.Serialize(writer, obj, xmlNameSpace); writer.Close(); memoryStream.Position = 0; XmlDocument serializeObjectDoc = new XmlDocument(); serializeObjectDoc.Load(memoryStream); return serializeObjectDoc.DocumentElement; } catch (Exception excep) { return null; } } } } public class StringResource { [XmlAttribute] public string DELETE; [XmlAttribute] public string ID; }

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  • C++ cin keeps skipping.....

    - by user69514
    I am having problems with my program. WHen I run it, it asks the user for the album, the title, but then it just exits the loop without asking for the price and the sale tax. Any ideas what's going on? This is a sample run Discounts effective for September 15, 2010 Classical 8% Country 4% International 17% Jazz 0% Rock 16% Show 12% Are there more transactions? Y/N y Enter Artist of CD: Sevendust Enter Title of CD: Self titled Enter Genre of CD: Rock enter price Are there more transactions? Y/N Thank you for shopping with us! Program code: #include <iostream> #include <string> using namespace std; int counter = 0; string discount_tiles[] = {"Classical", "Country", "International", "Jazz", "Rock", "Show"}; int discount_amounts[] = {8, 4, 17, 0, 16, 12, 14}; string date = "September 15, 2010"; // Array Declerations //Artist array char** artist = new char *[100]; //Title array char** title = new char *[100]; //Genres array char** genres = new char *[100]; //Price array double* price[100]; //Discount array double* tax[100]; // sale price array double* sale_price[100]; //sale tax array double* sale_tax[100]; //cash price array double* cash_price[100]; //Begin Prototypes char* getArtist(); char* getTitle(); char* getGenre(); double* getPrice(); double* getTax(); unsigned int* AssignDiscounts(); void ReadTransaction (char ** artist, char ** title, char ** genre, float ** cash, float & taxrate, int albumcount); void computesaleprice(); bool AreThereMore (); //End Prototypes bool areThereMore () { char answer; cout << "Are there more transactions? Y/N" << endl; cin >> answer; if (answer =='y' || answer =='Y') return true; else return false; } char* getArtist() { char * artist= new char [100]; cout << "Enter Artist of CD: " << endl; cin.getline(artist,100); cin.ignore(); return artist; } char* getTitle() { char * title= new char [100]; cout << "Enter Title of CD: " << endl; cin.getline(title,100); cin.ignore(); return title; } char* getGenre() { char * genre= new char [100]; cout << "Enter Genre of CD: " << endl; cin.getline(genre,100); cin.ignore(); return genre; } double* getPrice() { //double* price = new double(); //cout << "Enter Price of CD: " << endl; //cin >> *price; //return price; double p = 0.0; cout<< "enter price" << endl; cin >> p; cin.ignore(); double* pp = &p; return pp; } double* getTax() { double* tax= new double(); cout << "Enter local sales tax: " << endl; cin >> *tax; return tax; } int findDiscount(string str){ if(str.compare(discount_tiles[0]) == 0) return discount_amounts[0]; else if(str.compare(discount_tiles[0]) == 0) return discount_amounts[1]; else if(str.compare(discount_tiles[0]) == 0) return discount_amounts[2]; else if(str.compare(discount_tiles[0]) == 0) return discount_amounts[3]; else if(str.compare(discount_tiles[0]) == 0) return discount_amounts[4]; else if(str.compare(discount_tiles[0]) == 0) return discount_amounts[5]; else{ cout << "Error in findDiscount function" << endl; return 0; } } void computesaleprice() { /** fill in array for all purchases **/ for( int i=0; i<=counter; i++){ double temp = *price[i]; temp -= findDiscount(genres[i]); double* tmpPntr = new double(); tmpPntr = &temp; sale_price[i] = tmpPntr; delete(&temp); delete(tmpPntr); } } void printDailyDiscounts(){ cout << "Discounts effective for " << date << endl; for(int i=0; i < 6; i++){ cout << discount_tiles[i] << "\t" << discount_amounts[i] << "%" << endl; } } //Begin Main int main () { for( int i=0; i<100; i++){ artist[i]=new char [100]; title[i]=new char [100]; genres[i]=new char [100]; price[i] = new double(0.0); tax[i] = new double(0.0); } // End Array Decleration printDailyDiscounts(); bool flag = true; while(flag == true){ if(areThereMore() == true){ artist[counter] = getArtist(); title[counter] = getTitle(); genres[counter] = getGenre(); price[counter] = getPrice(); //tax[counter] = getTax(); //counter++; flag = true; } else { flag = false; } } //compute sale prices //computesaleprice(); cout << "Thank you for shopping with us!" << endl; return 0; } //End Main /** void ReadTransaction (char ** artist, char ** title, char ** genre, float ** cash, float & taxrate, int albumcount) { strcpy(artist[albumcount],getArtist()); strcpy(title[albumcount],getTitle()); strcpy(genre[albumcount],getGenre()); //cash[albumcount][0]=computesaleprice();??????? //taxrate=getTax;?????????????? } * * */ unsigned int * AssignDiscounts() { unsigned int * discount = new unsigned int [7]; cout << "Enter Classical Discount: " << endl; cin >> discount[0]; cout << "Enter Country Discount: " << endl; cin >> discount[1]; cout << "Enter International Discount: " << endl; cin >> discount[2]; cout << "Enter Jazz Discount: " << endl; cin >> discount[3]; cout << "Enter Pop Discount: " << endl; cin >> discount[4]; cout << "Enter Rock Discount: " << endl; cin >> discount[5]; cout << "Enter Show Discount: " << endl; cin >> discount[6]; return discount; } /** char ** AssignGenres () { char ** genres = new char * [7]; for (int x=0;x<7;x++) genres[x] = new char [20]; strcpy(genres [0], "Classical"); strcpy(genres [1], "Country"); strcpy(genres [2], "International"); strcpy(genres [3], "Jazz"); strcpy(genres [4], "Pop"); strcpy(genres [5], "Rock"); strcpy(genres [6], "Show"); return genres; } **/ float getTax(float taxrate) { cout << "Please enter store tax rate: " << endl; cin >> taxrate; return taxrate; }

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  • Problem with writing a hexadecimal string

    - by quilby
    Here is my code /* gcc -c -Wall -g main.c gcc -g -lm -o main main.o */ #include <stdlib.h> #include <stdio.h> #include <string.h> void stringToHex(const char* string, char* hex) { int i = 0; for(i = 0; i < strlen(string)/2; i++) { printf("s%x", string[2*i]); //for debugging sprintf(&hex[i], "%x", string[2*i]); printf("h%x\n", hex[i]); //for debugging } } void writeHex(char* hex, int length, FILE* file, long position) { fseek(file, position, SEEK_SET); fwrite(hex, sizeof(char), length, file); } int main(int argc, char** argv) { FILE* pic = fopen("hi.bmp", "w+b"); const char* string = "f2"; char hex[strlen(string)/2]; stringToHex(string, hex); writeHex(hex, strlen(string)/2, pic, 0); fclose(pic); return 0; } I want it to save the hexadecimal number 0xf2 to a file (later I will have to write bigger/longer numbers though). The program prints out - s66h36 And when I use hexedit to view the file I see the number '36' in it. Why is my code not working? Thanks!

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  • In C#, are event handler arguments covariant?

    - by Roger Lipscombe
    Maybe covariant's not the word, but if I have a class that raises an event, with (e.g.) FrobbingEventArgs, am I allowed to handle it with a method that takes EventArgs? Here's some code: class Program { static void Main(string[] args) { Frobber frobber = new Frobber(); frobber.Frobbing += FrobberOnFrobbing; frobber.Frob(); } private static void FrobberOnFrobbing(object sender, EventArgs e) { // Do something interesting. Note that the parameter is 'EventArgs'. } } internal class Frobber { public event EventHandler<FrobbingEventArgs> Frobbing; public event EventHandler<FrobbedEventArgs> Frobbed; public void Frob() { OnFrobbing(); // Frob. OnFrobbed(); } private void OnFrobbing() { var handler = Frobbing; if (handler != null) handler(this, new FrobbingEventArgs()); } private void OnFrobbed() { var handler = Frobbed; if (handler != null) handler(this, new FrobbedEventArgs()); } } internal class FrobbedEventArgs : EventArgs { } internal class FrobbingEventArgs : EventArgs { } The reason I ask is that ReSharper seems to have a problem with (what looks like) the equivalent in XAML, and I'm wondering if it's a bug in ReSharper, or a mistake in my understanding of C#.

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  • How to modify/replace option set file when building from command line?

    - by Heinrich Ulbricht
    I build packages from a batch file using commands like: msbuild ..\lib\Package.dproj /target:Build /p:config=%1 The packages' settings are dependent on an option set: <Import Project="..\optionsets\COND_Defined.optset" Condition="'$(Base)'!='' And Exists('..\optionsets\COND_Defined.optset')"/> This option set defines a conditional symbol many of my packages depend on. The file looks like this: <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003"> <PropertyGroup> <DCC_Define>CONDITION;$(DCC_Define)</DCC_Define> </PropertyGroup> <ProjectExtensions> <Borland.Personality>Delphi.Personality.12</Borland.Personality> <Borland.ProjectType>OptionSet</Borland.ProjectType> <BorlandProject> <Delphi.Personality/> </BorlandProject> <ProjectFileVersion>12</ProjectFileVersion> </ProjectExtensions> </Project> Now I need two builds: one with the condition defined and one without. My attack vector would be the option set file. I have some ideas on what to do: write a program which modifies the option set file, run this before batch build fiddle with the project files and modify the option set path to contain an environment variable, then have different option sets in different locations But before starting to reinvent the wheel I'd like to ask how you would tackle this task? Maybe there are already means meant to support such a case (like certain command line switches, things I could configure in Delphi or batch file magic).

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  • Something preventing default (explorer-style) CListCtrl jump to line behaviour

    - by andywebsdale
    I'm maintaining an MFC/COM/ATL 45-odd project solution originally written with VS6. I'm now using VS2008. I'm looking at a list control(vanilla CListCtrl) which doesn't behave as we think it should. Normally in an MFC list control you can press a key, (Q say) & selection will jump down to the 1st line beginning with 'Q' (like windows explorer). Does anyone have an idea as to why this might not happen? The styles/Extended styles are set the same as another control in the same project, which DOES work OK. Do I have to send my own message, or is there a flag, etc. that controls that functionality or what? Normally Google would supply the answer, but I haven't been able to frame my query correctly to come up with the relevant info this time. Here's the line from the .rc file for the CListCtrl that doesn't jump to a line on keypress: CONTROL "List1",IDC_BAL_LIST,"SysListView32",LVS_REPORT | LVS_SHOWSELALWAYS | WS_BORDER | WS_TABSTOP,0,73,493,230 And here's a line from the same .rc file showing a list control that does do that: CONTROL "List1",IDC_LIST1,"SysListView32",LVS_REPORT | LVS_SHOWSELALWAYS | WS_BORDER | WS_TABSTOP,1,38,501,219 As you can see, there's no obvious difference to the properties, so what program code would affect it?

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  • Android maps out of memory error

    - by SamB09
    Hi , sometimes when running a google maps program with an overlay image i will receive a bit map out of memory error. It always seems to be at a random point in the app. Im not sure how to solve this. Anyone have any ideas ? My overlay code is below , im not sure if you need to see the class its called in though? public class MyOverlay2 extends Overlay { private static final double MAX_TAP_DISTANCE_KM = 3; // Rough approximation - one degree = 50 nautical miles private static final double MAX_TAP_DISTANCE_DEGREES = MAX_TAP_DISTANCE_KM * 0.5399568 * 50; private final GeoPoint gPoint; private final Context cont; private final int draw; // private final int lat; public MyOverlay2(Context cont, GeoPoint gPoint1, int draw) { // constructor will be called in the userLocation class to draw an overly image this.cont = cont; this.gPoint = gPoint1; this.draw = draw; } @Override public boolean draw(Canvas canvas, MapView mapView, boolean shadow, long when) { // constructor takes 3 arguments super.draw(canvas, mapView, shadow); // Convert geo coordinates to screen pixels Point screenPoint = new Point(); mapView.getProjection().toPixels(gPoint, screenPoint); //Read the image from the xml resource using a bitmap factory BitmapFactory.Options options=new BitmapFactory.Options(); options.inSampleSize = 1; Bitmap preview_bitmap=BitmapFactory.decodeResource(cont.getResources(),R.drawable.monday12,options); //draw the image at the location specified by the co-ordinates canvas.drawBitmap(preview_bitmap, screenPoint.x - preview_bitmap.getWidth() /2, screenPoint.y - preview_bitmap.getHeight()/2 , null); // get the images height and width values divided by two draw the image at the specified screen points return true; } @Override public boolean onTap(GeoPoint s, MapView mapView) { // Handle tapping on the overlay here return true; } }

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  • How can I work around the fact that in C++, sin(M_PI) is not 0?

    - by Adam Doyle
    In C++, const double Pi = 3.14159265; cout << sin(Pi); // displays: 3.58979e-009 it SHOULD display the number zero I understand this is because Pi is being approximated, but is there any way I can have a value of Pi hardcoded into my program that will return 0 for sin(Pi)? (a different constant maybe?) In case you're wondering what I'm trying to do: I'm converting polar to rectangular, and while there are some printf() tricks I can do to print it as "0.00", it still doesn't consistently return decent values (in some cases I get "-0.00") The lines that require sin and cosine are: x = r*sin(theta); y = r*cos(theta); BTW: My Rectangular - Polar is working fine... it's just the Polar - Rectangular Thanks! edit: I'm looking for a workaround so that I can print sin(some multiple of Pi) as a nice round number to the console (ideally without a thousand if-statements) edit: In case anyone's curious, this was what I landed on: double sin2(double theta) // in degrees { double s = sin(toRadians(theta)); if (fabs(s - (int)s) < 0.000001) { return floor(s + 0.5); } return s; } where toRadians() is a macro that converts to radians

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  • How is a relative JMP (x86) implemented in an Assembler?

    - by Pindatjuh
    While building my assembler for the x86 platform I encountered some problems with encoding the JMP instruction: enc inst size in bytes EB cb JMP rel8 2 E9 cw JMP rel16 4 (because of 0x66 16-bit prefix) E9 cd JMP rel32 5 ... (from my favourite x86 instruction website, http://siyobik.info/index.php?module=x86&id=147) All are relative jumps, where the size of each encoding (operation + operand) is in the third column. Now my original (and thus fault because of this) design reserved the maximum (5 bytes) space for each instruction. The operand is not yet known, because it's a jump to a yet unknown location. So I've implemented a "rewrite" mechanism, that rewrites the operands in the correct location in memory, if the location of the jump is known, and fills the rest with NOPs. This is a somewhat serious concern in tight-loops. Now my problem is with the following situation: b: XXX c: JMP a e: XXX ... XXX d: JMP b a: XXX (where XXX is any instruction, depending on the to-be assembled program) The problem is that I want the smallest possible encoding for a JMP instruction (and no NOP filling). I have to know the size of the instruction at c before I can calculate the relative distance between a and b for the operand at d. The same applies for the JMP at c: it needs to know the size of d before it can calculate the relative distance between e and a. How do existing assemblers implement this, or how would you implement this? This is what I am thinking which solves the problem: First encode all the instructions to opcodes between the JMP and it's target, and if this region contains a variable-sized opcode, use the maximum size, i.e. 5 for JMP. Then in some conditions, the JMP is oversized (because it may fit in a smaller encoding): so another pass will search for oversized JMPs, shrink them, and move all instructions ahead), and set absolute branching instructions (i.e. external CALLs) after this pass is completed. I wonder, perhaps this is an over-engineered solution, that's why I ask this question.

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  • Python Turtle Graphics, how to plot functions over an interval?

    - by TheDragonAce
    I need to plot a function over a specified interval. The function is f1, which is shown below in the code, and the interval is [-7, -3]; [-1, 1]; [3, 7] with a step of .01. When I execute the program, nothing is drawn. Any ideas? import turtle from math import sqrt wn = turtle.Screen() wn.bgcolor("white") wn.title("Plotting") mypen = turtle.Turtle() mypen.shape("classic") mypen.color("black") mypen.speed(10) while True: try: def f1(x): return 2 * sqrt((-abs(abs(x)-1)) * abs(3 - abs(x))/((abs(x)-1)*(3-abs(x)))) * \ (1 + abs(abs(x)-3)/(abs(x)-3))*sqrt(1-(x/7)**2)+(5+0.97*(abs(x-0.5)+abs(x+0.5))-\ 3*(abs(x-0.75)+abs(x+0.75)))*(1+abs(1-abs(x))/(1-abs(x))) mypen.penup() step=.01 startf11=-7 stopf11=-3 startf12=-1 stopf12=1 startf13=3 stopf13=7 def f11 (startf11,stopf11,step): rc=[] y = f1(startf11) while y<=stopf11: rc.append(startf11) #y+=step mypen.setpos(f1(startf11)*25,y*25) mypen.dot() def f12 (startf12,stopf12,step): rc=[] y = f1(startf12) while y<=stopf12: rc.append(startf12) #y+=step mypen.setpos(f1(startf12)*25, y*25) mypen.dot() def f13 (startf13,stopf13,step): rc=[] y = f1(startf13) while y<=stopf13: rc.append(startf13) #y+=step mypen.setpos(f1(startf13)*25, y*25) mypen.dot() f11(startf11,stopf11,step) f12(startf12,stopf12,step) f13(startf13,stopf13,step) except ZeroDivisionError: continue

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  • Color picker does not give gradient appearance

    - by ykaratoprak
    i added below codes. But it generates to me 16 color. but i need 16 color between "red" and "khaki". i don't need gradient flow. My colors look like gradient flow. My colors must not closer to each other. Because i will use this codes return values in chart columns. they are too near each other. static class Program { [STAThread] static void Main() { Form form = new Form(); Color start = Color.Red, end = Color.Khaki; for (int i = 0; i < 16; i++) { int r = Interpolate(start.R, end.R, 15, i), g = Interpolate(start.G, end.G, 15, i), b = Interpolate(start.B, end.B, 15, i); Button button = new Button(); button.Dock = DockStyle.Top; button.BackColor = Color.FromArgb(r, g, b); form.Controls.Add(button); button.BringToFront(); } Application.Run(form); } static int Interpolate(int start, int end, int steps, int count) { float s = start, e = end, final = s + (((e - s) / steps) * count); return (int)final; } }

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  • standard way to perform a clean shutdown with Boost.Asio

    - by Timothy003
    I'm writing a cross-platform server program in C++ using Boost.Asio. Following the HTTP Server example on this page, I'd like to handle a user termination request without using implementation-specific APIs. I've initially attempted to use the standard C signal library, but have been unable to find a design pattern suitable for Asio. The Windows example's design seems to resemble the signal library closest, but there's a race condition where the console ctrl handler could be called after the server object has been destroyed. I'm trying to avoid race conditions that cause undefined behavior as specified by the C++ standard. Is there a standard (correct) way to stop the server? So far: #include <csignal> #include <functional> #include <boost/asio.hpp> using std::signal; using boost::asio::io_service; extern "C" { static void handle_signal(int); } namespace { std::function<void ()> sighandler; } void handle_signal(int) { sighandler(); } int main() { io_service s; sighandler = std::bind(&io_service::stop, &s); auto res = signal(SIGINT, &handle_signal); // race condition? SIGINT raised before I could set ignore back if (res == SIG_IGN) signal(SIGINT, SIG_IGN); res = signal(SIGTERM, &handle_signal); // race condition? SIGTERM raised before I could set ignore back if (res == SIG_IGN) signal(SIGTERM, SIG_IGN); s.run(); // reset signals signal(SIGTERM, SIG_DFL); signal(SIGINT, SIG_DFL); // is it defined whether handle_signal can still be in execution at this // point? sighandler = nullptr; }

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  • Performance Difference between HttpContext user and Thread user

    - by atrueresistance
    I am wondering what the difference between HttpContext.Current.User.Identity.Name.ToString.ToLower and Thread.CurrentPrincipal.Identity.Name.ToString.ToLower. Both methods grab the username in my asp.net 3.5 web service. I decided to figure out if there was any difference in performance using a little program. Running from full Stop to Start Debugging in every run. Dim st As DateTime = DateAndTime.Now Try 'user = HttpContext.Current.User.Identity.Name.ToString.ToLower user = Thread.CurrentPrincipal.Identity.Name.ToString.ToLower Dim dif As TimeSpan = Now.Subtract(st) Dim break As String = "nothing" Catch ex As Exception user = "Undefined" End Try I set a breakpoint on break to read the value of dif. The results were the same for both methods. dif.Milliseconds 0 Integer dif.Ticks 0 Long Using a longer duration, loop 5,000 times results in these figures. Thread Method run 1 dif.Milliseconds 125 Integer dif.Ticks 1250000 Long run 2 dif.Milliseconds 0 Integer dif.Ticks 0 Long run 3 dif.Milliseconds 0 Integer dif.Ticks 0 Long HttpContext Method run 1 dif.Milliseconds 15 Integer dif.Ticks 156250 Long run 2 dif.Milliseconds 156 Integer dif.Ticks 1562500 Long run 3 dif.Milliseconds 0 Integer dif.Ticks 0 Long So I guess what is more prefered, or more compliant with webservice standards? If there is some type of a performance advantage, I can't really tell. Which one scales to larger environments easier?

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  • How do I simulate the usage of a sequence of web pages?

    - by Rory Becker
    I have a simple sequence of web pages written in ASP.Net 3.5 SP1. Page1 - A Logon Form.... txtUsername, txtPassword and cmdLogon Page2 - A Menu (created using DevExpress ASP.Net controls) Page3 - The page redirected to by the server in the event that the user picks the right menu option in Page2 I would like to create a threaded program to simulate many users trying to use this sequence of pages. I have managed to create a host Winforms app which Launches a new thread for each "User" I have further managed to work out the basics of WebRequest enough to perform a request which retrieves the Logon page itself. Dim Request As HttpWebRequest = TryCast(WebRequest.Create("http://MyURL/Logon.aspx"), HttpWebRequest) Dim Response As HttpWebResponse = TryCast(Request.GetResponse(), HttpWebResponse) Dim ResponseStream As StreamReader = New StreamReader(Response.GetResponseStream(), Encoding.GetEncoding(1252)) Dim HTMLResponse As String = ResponseStream.ReadToEnd() Response.Close() ResponseStream.Close() Next I need to simulate the user having entered information into the 2 TextBoxes and pressing logon.... I have a hunch this requires me to add the right sort of "PostData" to the request. before submitting. However I'm also concerned that "ViewState" may be an issue. Am I correct regarding the PostData? How do I add the postData to the request? Do I need to be concerned about Viewstate? Update: While I appreciate that Selenium or similar products are useful for acceptance testing , I find that they are rather clumsy for what amounts to load testing. I would prefer not to load 100 instances of Firefox or IE in order to simulate 100 users hitting my site. This was the reason I was hoping to take the ASPNet HttpWebRequest route.

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  • Hotkeys in webapps

    - by Johoo
    When creating webapps, is there any guidelines on which keys you can use for your own hotkeys without overriding too many of the browsers default hotkeys. For example i might want to have a custom copy command for copying entire sets of data that only makes sense for my program instead of just text. The logical combination for this would be ctrl+c but that would destroy the default copy hotkey for normal text. One solution i was thinking about is to only catch the hotkey when it "makes sense" but when you use some advanced custom selection it might be hard to differentiate if your data is focused, if text is selected or both. Right now i am only using single keys as the hotkey, so just 'c' for the example above and this seems to be what most other sites are doing too. The problem is that if you have text input this doesn't work so good. Is this the best solution? To clarify I'm talking about advanced webapps that behave more like normal programs and not just some website presenting information(even though i think these guidlines would be valid for both cases). So for the copy example it might not be a big deal if you can't copy the text in the menu but when ctrl+tab, alt+d or ctrl+e doesn't work i would be really pissed, cough flash cough.

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  • Setting Up OpenCV and .lib files

    - by jhaip
    I have been trying to set up OpenCV for the past few days with no results. I am using Windows 7 and VS C++ 2008 express edition. I have downloaded and installed OpenCV 2.1 and some of the examples work. I downloaded CMake and ran it to generate the VS project files and built all of them but there with several errors, and couldn't get any farther than that. When I ran CMake I configured it to use the VS 9 compiler, and then it brought up a list of items in red such as BUILD_EXAMPLES, BUILD_LATEX_DOCS, ect. All of them were unchecked except BUILD_NEW_PYTHON_SUPPORT, BUILD_TESTS, ENABLE_OPENMP, and OPENCV_BUILD_3RDPARTY_LIBS. I configured and generate without changing anything and then it generated the VS files such as ALL_BUILD.vcproj. I built the OpenCV VS solution in debug mode and it had 15 failures (maybe this is part of the problem or is it because I don't have python and stuff like that?) Now there was a lib folder created after building but inside there was just this VC++ Minimum Rebuild Dependency file and Program Debug Database file, both called cvhaartraining. I believe it should have created the .lib files I need instead of this. Also, the bin folder now has a folder called Debug with the same types of files with names like cv200d and cvaux200d. Believe I need those .lib files to move forward. I would also greatly appreciate if someone could direct me to a reliable tutorial to set up VS for OpenCV because I have been reading a lot of tutorials and they all say different things such as some say to configure Window's environment variables and other say files are located in folders such as OpenCV/cv which I don't have. I have gotten past the point of clear headed thinking so if anyone could offer some direction or a simple list of the files I need to link then I would be thankful. Also a side question: why when linking the OpenCV libs do you have to put them in quotes?

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  • How to access a superclass's class attributes in Python?

    - by Brecht Machiels
    Have a look at the following code: class A(object): defaults = {'a': 1} def __getattr__(self, name): print('A.__getattr__') return self.get_default(name) @classmethod def get_default(cls, name): # some debug output print('A.get_default({}) - {}'.format(name, cls)) try: print(super(cls, cls).defaults) # as expected except AttributeError: #except for the base object class, of course pass # the actual function body try: return cls.defaults[name] except KeyError: return super(cls, cls).get_default(name) # infinite recursion #return cls.__mro__[1].get_default(name) # this works, though class B(A): defaults = {'b': 2} class C(B): defaults = {'c': 3} c = C() print('c.a =', c.a) I have a hierarchy of classes each with its own dictionary containing some default values. If an instance of a class doesn't have a particular attribute, a default value for it should be returned instead. If no default value for the attribute is contained in the current class's defaults dictionary, the superclass's defaults dictionary should be searched. I'm trying to implement this using the recursive class method get_default. The program gets stuck in an infinite recursion, unfortunately. My understanding of super() is obviously lacking. By accessing __mro__, I can get it to work properly though, but I'm not sure this is a proper solution. I have the feeling the answer is somewhere in this article, but I haven't been able to find it yet. Perhaps I need to resort to using a metaclass?

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  • Trying to write a video file using OpenCV

    - by Ted pottel
    Hi , I’m trying to use OpenCV to write a video file. I have a simple program that loads frames from a video file then accepts to save them At first the cvCreateVideoWrite always return NULL. I got a answer from your group saying it returns separate images and to try to change the file name to test0001.png, this worked. But now the cvWriteFrame function always fails, the code is CString path; path="d:\\mice\\Test_Day26_2.avi"; CvCapture* capture = cvCaptureFromAVI(path); IplImage* img = 0; CvVideoWriter *writer = 0; int isColor = 1; int fps = 25; // or 30 int frameW = 640; // 744 for firewire cameras int frameH = 480; // 480 for firewire cameras writer=cvCreateVideoWriter("d:\\mice\\test0001.png",CV_FOURCC('P','I','M','1'), fps,cvSize(frameW,frameH),isColor); if (writer==0) MessageBox("could not open writter"); int nFrames = 50; for(int i=0;i<nFrames;i++){ if (!cvGrabFrame(capture)) MessageBox("could not grab frame"); img=cvRetrieveFrame(capture); // retrieve the captured frame if (img==0) MessageBox("could not retrive data"); if (!cvWriteFrame(writer,img) ) MessageBox("could not write frame"); } cvReleaseVideoWriter(&writer); Any help would be GREAT - Ted

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  • Compilation Error: "The modifier 'public' is not valid for this item" while creating public method o

    - by Lalit
    I am getting this error while creating public method on a class for explicitly implementing the interface. I have the workaround: by removing the explicit implementation of PrintName Method, But surprised why i am getting this error. Can anyone explain the error. Code for Library: using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace Test.Lib1 { public class Customer : i1 { public string i1.PrintName() //Error Here... { return this.GetType().Name + " called from interface i1"; } } public interface i1 { string PrintName(); } interface i2 { string PrintName(); } } Code for Console Test Application: using System; using System.Collections.Generic; using System.Linq; using System.Text; using Test.Lib1; namespace ca1.Test { class Program { static void Main(string[] args) { Customer customer = new Customer(); Console.WriteLine(customer.PrintName()); //i1 i1o = new Customer(); //Console.WriteLine(i1o.printname()); //i2 i2o = new Customer(); //Console.WriteLine(i2o.printname()); } } }

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  • Verizon SongID - How is it programmed?

    - by CheeseConQueso
    For anyone not familiar with Verizon's SongID program, it is a free application downloadable through Verizon's VCast network. It listens to a song for 10 seconds at any point during the song and then sends this data to some all-knowing algorithmic beast that chews it up and sends you back all the ID3 tags (artist, album, song, etc...) The first two parts and last part are straightforward, but what goes on during the processing after the recorded sound is sent? I figure it must take the sound file (what format?), parse it (how? with what?) for some key identifiers (what are these? regular attributes of wave functions? phase/shift/amplitude/etc), and check it against a database. Everything I find online about how this works is something generic like what I typed above. From audiotag.info This service is based on a sophisticated audio recognition algorithm combining advanced audio fingerprinting technology and a large songs' database. When you upload an audio file, it is being analyzed by an audio engine. During the analysis its audio “fingerprint” is extracted and identified by comparing it to the music database. At the completion of this recognition process, information about songs with their matching probabilities are displayed on screen.

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  • getting expat to use .dtd for entity replacement in python

    - by nicolas78
    I'm trying to read in an xml file which looks like this <?xml version="1.0" encoding="ISO-8859-1"?> <!DOCTYPE dblp SYSTEM "dblp.dtd"> <dblp> <incollection> <author>Jos&eacute; A. Blakeley</author> </incollection> </dblp> The point that creates the problem looks is the Jos&eacute; A. Blakeley part: The parser calls its character handler twice, once with "Jos", once with " A. Blakeley". Now I understand this may be the correct behaviour if it doesn't know the eacute entity. However, this is defined in the dblp.dtd, which I have. I don't seem to be able to convince expat to use this file, though. All I can say is p = xml.parsers.expat.ParserCreate() # tried with and without following line p.SetParamEntityParsing(xml.parsers.expat.XML_PARAM_ENTITY_PARSING_ALWAYS) p.UseForeignDTD(True) f = open(dblp_file, "r") p.ParseFile(f) but expat still doesn't recognize my entity. Why is there no way to tell expat which DTD to use? I've tried putting the file into the same directory as the XML putting the file into the program's working directory replacing the reference in the xml file by an absolute path What am I missing? Thx.

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