265 Discussion / Question Topics
Remove Filter  | I am trying to parse the content of a wiki page. In a string like this: [code] ==Heading1== <test> some text here </test> ==Heading2== <test> even more text </test> [/code] I need to obtain "Heading1", "some text here", "Heading2" and "even more text". I got this to work: [code] import … |
| | I am trying to strip a prefix from a string, e.g. turn [code] VTK/Examples/Test [/code] Into [code] Test [/code] Sometimes the string does not contain the prefix, in which case I would expect nothing to happen. However, [code] >>> S="Main Page" >>> S.strip("VTK/Examples/") 'Main Pag' [/code] You can see that …  |
| | Is there a data structure that lets me push and pop things onto/off of a queue, but also doesn't allow duplicates? E.g. I want [code] queue a; a.push(1); a.push(2); a.push(2); a.push(3); [/code] to only have 3 elements, because 2 was added twice so the second time it is just ignored. … |
| | After reading a few tutorials, it looks like this: [url]http://www.rpi.edu/~doriad/Examples/Table/[/url] should make a full (100%) width table. However, the width is actually very small and the table is on the left of the page. Does anyone see what is wrong here? Thanks, Dave |
| | This code: [code] #include <iostream> class Parent { int name; class Child { int school; void test() { std::cout << this->name; } }; }; int main(int argc, char *argv[]) { Parent MyParent; return 0; } [/code] Generates this error: [code] error: 'class Parent::Child' has no member named 'name' [/code] Is … |
| | I have some code that uses _finite (I think from float.h) that my linker complains is not declared. I think this might be a "windows only" function. Is there an equivalent function that I can call that will work cross platform? Thanks, Dave |
| | I am trying to compile some old code a colleague gave me. I have MyClass.h [code] class MyClass { public: static int UseIndex; .... }; #include "MyClass.inl" [/code] MyClass.inl [code] ... int TreeNodeData::UseIndex=1; ... [/code] I am getting: [code] multiple definition of `MyClass::UseIndex' first defined here [/code] I got several … |
| | I am trying to get a variable number of arguments in one function, and pass them to another function. I tried this: [code] #include <iostream> #include <stdarg.h> void Function1(unsigned int num, ...); void Function2(unsigned int num, va_list ap); int main(int argc, char *argv[]) { Function1(3, 1, 2, 3); return 0; … |
| | When compiling some working code on Fedora 11, I am getting this error: [code] /usr/include/c++/4.4.1/cstdarg:56: error: ‘::va_list’ has not been declared [/code] I am using: [code] [doriad@davedesktop VTK]$ g++ --version g++ (GCC) 4.4.1 20090725 (Red Hat 4.4.1-2) [/code] Does anyone know what the problem could be? Thanks, Dave |
| | I am trying to compile some software I found online. I am getting a bunch of these errors: [code] No rule to make target `/usr/lib/gcc-lib/i386-redhat-linux/3.2.2/include/stdarg.h', needed by `formCluster.o'. Stop. [/code] In the Makefiles, there are certainly lines like this: [code] transform.o: /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/include/stddef.h [/code] The errors seem to go away if … |
| | I am trying to get some code I found online to compile. It looked like this: [code] #include <iostream> #include <list> using std::list; template <class T> class leda_list : public std::list<T> { private: iterator loopIter; [/code] the error was: ‘iterator’ does not name a type I tried changing it to: … |
| | I want to make a type to differentiate degrees and radians. I wanted something like this to produce a compiler error: [code] #include <iostream> typedef double Degree; typedef double Radian; void MyFunction(Radian angle); int main() { Degree foo = 3.0; return 0; } void MyFunction(Radian angle) { std::cout << "Success." …  |
| | If I go to: view -> arrange by -> current view -> customize current view -> other settings I can change the "row font" size for the current folder. If I have 100 folders and I want to change the font size for the messages in all of them, you … |
| | Why people write such cryptic code I will never understand... Can someone explain what is going on in the following: [code] double color = {1,2,3}; double *ptr; // ... assign ptr .... *ptr = *color++; ptr++; [/code] So this line [icode] *ptr = *color++; [/icode] sets the value of the …  |
| | Is there a way to see what a macro gets expanded to? I tried to put it in quotes and use printf, but of course printf just printed exactly the string. The result of: [code] #define SetMacro(name,type) \ virtual void Set##name (type _arg) int main() { printf("SetMacro(Test, int)"); } [/code] … |
| | A friend of mine has a big table on his website: [url]http://www.rpi.edu/~chens/Research.html[/url] I think it looks great, so I tried to copy this style/code, but it is making too many columns: [url]http://www.rpi.edu/~doriad/TechnicalReports.html[/url] I read [url]http://www.w3.org/TR/html4/struct/tables.html[/url] , but it looks to me like I have done everything right (all it is … |
| | I have some sections like: [code] <h3>EngineeringNotes.net</h3> <br>I have never .... [/code] (see this page: [url]http://www.rpi.edu/~doriad/Personal.html[/url]) Why is there such an enormous space between the header and the text? I thought <br> should just insert a single line break? Thanks, Dave |
| | Consider two classes, PersonClass and LawyerClass. If LawyerClass derives from PersonClass, you can create a PersonClass* as a LawyerClass, like [code] PersonClass* Person = new LawyerClass; [/code] then you can convert it to a LawyerClass* with [code] LawyerClass* Lawyer = static_cast<LawyerClass*>(Person); [/code] However, if you don't know that the person … |
| | Say you have a class that has members [code] private: double a,b,c,d,e,f,g,h,i; [/code] You can make an accessor like: [code] double operator[](int index) { if(index == 0) return a; else if(index == 1) return b; else if(index == 2) return c; } [/code] But how would you do something like … |
| | If I have the following setup: [code] Point* MyPoint = Object->GetMyPoint(); if(MyPoint->GetValue() != 2) do something; else do something else; [/code] If MyPoint is NULL or invalid, the MyPoint->GetValue() will cause a segfault. This should fix it: [code] Point* MyPoint = Object->GetMyPoint(); if(MyPoint) { if(MyPoint->GetValue() != 2) do A; else …  |
| | Is there a "correct" way to draw a line betwee the header and body of a document in word 2007? I've been using a Shapes->Lines line, but it seems silly because there is no way to center it, etc. Any ideas? Thanks, Dave |
| | With this code: [url]http://www.rpi.edu/~doriad/Daniweb/maxflow/[/url] If I run [code] g++ Example.cpp graph.cpp [/code] with g++ 3.3, everything works fine. However if I run the same command with g++ 4.4, I get this error: [code] Example.cpp:(.text+0x38): undefined reference to `Graph<int, int, int>::Graph(int, int, void (*)(char*))' [/code] Does anyone know how I can … |
| | I have written an integration function (of one variable) [code] double integrate(double (*f)(double), const double a, const double b) [/code] However, now I want to integrate a function of one variable, but the c++ function has an additional parameter: [code] double f(double x, bool flag) { if(flag == true) f … |
| | With normal folders, you can right click them and say "Remove from favorite folders, as per here: [url]http://office.microsoft.com/en-us/outlook/HA011176721033.aspx[/url] However, Calendar and Contacts don't have that option. How would one remove them? Thanks, David  |
| | I am looking at some open source code and I am a bit confused. There is an Allocator class: [code] class Allocator{ [/code] Then in another class, they have: [code] class Octree{ public: static Allocator<OctNode> Allocator; [/code] When trying to compile, I am getting: [code] error: declaration of 'Allocator<OctNode<NodeData, Real> … |
| | I am trying to compile some code (Example.cpp from here: [url]http://www.rpi.edu/~doriad/Daniweb/maxflow/[/url]). I am getting [code] Example.cpp:(.text+0x38): undefined reference to `Graph<int, int, int>::Graph(int, int, void (*)(char*))' [/code] This is clearly a template instantiation problem. I see that there is a file called instances.inc that defines the <int,int,int> class, do I need …  |
| | Is there anyway to get images to be the "correct" size - i.e. fit the width of the text? This is what currently happens: [url]http://engineeringnotes.net/personal/pictures.shtml[/url] Thanks, Dave  |
| | I'm still very new to css, so I'm sure this is just some really silly thing: [url]http://engineeringnotes.net/personal/[/url] Does anyone know why the text is hanging off the left side of the page (on the "home" page and the "publications" page? Thanks, Dave |
| | When debugging my code, I put a break point at this line: [code] std::set<unsigned int>::iterator it; [/code] When I step over that line, I get "Debugger reported the following error: cannot access memory at address 0x10". I am using KDevelop that ships with Fedora 11. I've used that line of …  |
| | I have a function like this: [code] bool MyFunction(dist) { if(dist < 1.2) { std::cout << "Passed test!" << std::endl; return true; } else { std::cout << "Failed test!" << std::endl; return false; } std::cout << std::endl; } [/code] gcc tells me "warning- control reaches end of non-void function". However, … |
| | I made 2 classes, Point and Point3D: Point.h: [code] #ifndef POINT_H #define POINT_H #include <iostream> template <typename T> class Point { protected: T X,Y,Z; public: Point(const T x, const T y, const T z) : X(x), Y(y), Z(z) {} T getX() {return X;}; T getY() {return Y;}; T getZ() {return … |
| | This may be a gdb problem or a KDevelop problem, but I'm hoping it's a c++ problem so it's more easily fixed! If I "execute" my application either in KDevelop or from a terminal, it finishes and terminates without any problems. However, if I step through the code, when it … |
| | I have written a small program (it depends on big libraries, so I will not post the actual code) that performs correctly, but segfaults at the very end (main return). [code] int main() { ..... my code here... std::cout << "Finished." << std::endl; return 0; } [/code] I see "Finished." …  |
| | If I have a class in a namespace, like this: [code] #ifndef MyClass_h #define MyClass_h namespace NyNamespace { class MyClass { public: typedef double MyType; MyType Read(); }; } #endif [/code] And the implementation: [code] #include "MyClass.h" namespace MyNamespace { MyClass::MyType MyClass::Read() { MyClass::MyType A; return A; } } [/code] … |
| | When someone sends a very high resolution image to an account that is received by Outlook 2003, the behavior is to show you the image at its correct resolution, which sometimes only lets you see a very small part of it. Is there a way to set the client to … |
| | I installed Office 2003 on a computer, as I have done a zillion times. I setup outlook to get pop3 mail. When I click send/receive - it says sending - complete, receiving - complete, but it does not actually get any of the mail. I tried with outlook express and …  |
| | I have an abstract class NetworkTest and some derived classes PingTest, SMTPTest, and POP3Test. Each Test class overrides a Run() function and has it's own private member variables. I have a txt file for each type of test - ping.txt, pop3.txt, smtp.txt that defines the tests that should be run, … |
| | I have a superclass NetworkTest and 3 derived classes PingTest, Pop3Test, SMTPTest. I want to create a big list of all the tests, like this: [code] Dim Tests As New List(Of NetworkTest) Dim PingTests As List(Of PingTest) = ReadPingTestsFromFile(PingFile) Tests.AddRange(PingTests) Dim Pop3TestResults As List(Of Pop3Test) = ReadPOP3TestsFromFile(POP3File) Tests.AddRange(Pop3TestResults) Dim SMPTTests … |
| | I know you can't usually define things in the class like this: [code] class MyClass { double DefaultForward[3] = {0.0, 1.0, 0.0}; }; [/code] but I have some values that don't really make sense to set in the constructor - they are more "deeply connected" as THIS SHOULD ALWAYS BE … |
| | (As a warning - if at any point you think "umm why don't you just use X to get your 2 column display - I'm all for that! This is the only way I came up with). I want to end up nice looking display of data on the form … |
| | There is a pure virtual const function declared like wayyyy up the inheritance hierarchy that I need to override, but I would like to override it with a non-const function. I tried and it just complained that the pure virtual const function const was not implemented. I got around it … |
| | I frequent the c++ forum, and I've seen quite a number of posts that are about windows api/MFC stuff. This seems to be quite a separate thing than just "c++". Would it make sense to add a new forum to separate it? Dave |
| | I have a class called Scanner which casts rays into a 3d scene and records the resulting intersections. It has the following type of properties: Location (a 3d point) Forward (a 3d vector) Up (a 3d vector) min/max angle (the bounds of where to cast rays) theta/phi step (the directions … |
| | The problem is on the "MyIter = " line: [code] class OrientedPoint { .... class variables ... std::map<std::string, double> DoubleValues; ..... bool OrientedPoint::getDoubleValue(const std::string &ValueName, double &Value) const { std::map<std::string, double>::iterator MyIter; MyIter = DoubleValues.find(ValueName); [/code] The error produced is: [code] In member function 'bool OrientedPoint::getDoubleValue(const std::string&, double&) const': error: … |
| | Is there a way (without overloading) to call a function like this [code=cplusplus] GetValue("one"); //AND std::string test("one"); GetValue(test); [/code] The function is simply: [code=cplusplus] int GetValue(const std::string &MyString) { return MyMap[MyString]; } [/code] This overload does the job: [code=cplusplus] int GetValue(const char* MyString) { return MyMap[MyString]; } [/code] But that … |
| | Is there some minimum amount of time that has to pass before thread subscription will "instantly notify" me? For example (and this happens a lot) I post a question, someone answered and I received an email about this answer. Then I replied. Then someone else replied, and I didn't receive … |
| | I don't understand why can you do this: [code] Employee *emp; if (condition1) emp = new Employee(); else if (condition2) emp = new Manager(); [/code] but not this: [code] Employee emp; if (condition1) emp = Employee(); else if (condition2) { emp = Manager(); [/code] Maybe this is a TERRIBLE idea, …  |
| | I'm trying to start writing tests for all of my functions as per Test Driven Development. My question is, say I construct a test for "rotate vector". It would be something like this: [code] int TestRotateVector(const Vector &V) { Vector Original(1.0, 2.0); Vector Rotated = Original.Rotate(10); //rotate 10 degrees if(Rotated … |
| | i.e. [code] class A { int x = 5; }; [/code] I saw a mailing list post from October 08 where a guy asked if this was going to be added. gcc 4.4 was released April 09, so I would assume it would have been added by then? I haven't … |
| | If I do something like this: [code] print "%08d" % 2 [/code] It will print '00000002'. However, I want to change the "8" to a "3" at runtime (to get '002' instead). I tried this: [code] MyLength = 3 print "%0" + str(MyLength) + "d" % 2 [/code] but I … |
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