I'm building an interpreter and as I'm aiming for raw speed this time, every clock cycle matters for me in this (raw) case. Do you have any experience or information what of the both is faster: Vector or Array? All what matters is the speed I can access an element (opcode receiving), I don't care about inserting, allocation, sorting, et...
I am confused about how to use destructors when I have a std::vector of my class. So if I create a simple class as follows: class Test { private: int *big; public: Test () { big = new int[10000]; } ~Test () { delete [] big; } }; Then in my main function I do the following: Test tObj = Test(); vector<Test> tVec; tVec...
I'm trying to open simple vector graphics using Raphaël JS and I can't find any converter that would do the whole job. Is there any way to transfer vector graphics (SVG or anything from Illustrator, Inkscape) into Raphaël's JavaScript? ...
I'm making an extension to the Vector2 class. In my main code, I can say Vector2 v=new Vector2(); v.X=2; But in my extension, I can't. public static void SetToThree(this Vector2 vector) { vector.X=3; } v.SetToThree() doesn't change v. When I go line by line through the code, in the extension vector's X direction is cha...
std::vector<T> vec; // line #1 vec.reserve(100); // line #2 I am wondering if line #1 triggers a small allocation (say, memory for 10 Ts), or if the first allocation happens on line #2. Does the standard say anything about that? ...
This is the first part of a function I have that's causing my program to crash: vector<Student> sortGPA(vector<Student> student) { vector<Student> sorted; Student test = student[0]; cout << "here\n"; sorted.insert(student.begin(), student[0]); cout << "it failed.\n"; ... It crashes right at the sorted part...
I'm making an vector/matrix library for Game which utilizes SIMD unit on iPhone (3GS or later). How can I do this? I searched about this, now I know several options: Accelerate framework (BLAS+LAPACK+...) from Apple (iPhone OS 4) OpenMAX implementation library from ARM GCC auto-vectorization feature What's the most suitable way for v...
I'm trying to produce a single variable which is a concatenation of two chars e.g to go from "p30s4" "p28s4" to "p30s4 p28s4". I've tried cat and paste as shown below. Both return empty variables. What am I doing wrong? > blah = c("p30s4","p28s4") > blah [1] "p30s4" "p28s4" > foo = cat(blah) p30s4 p28s4 > foo NULL > foo = paste(c...
I have do an extensive calculation on a big vector of integers. The vector size is not changed during the calculation. The size of the vector is frequently accessed by the code. What is faster in general: using the vector::size() function or using helper constant vectorSize storing the size of the vector? I know that compilers usually a...
Hello ! I am trying to get the most occurring term frequencies for every particular document in Lucene index. I am trying to set the treshold of top occuring terms that I care about, maybe 20 However, I am getting the "no inclosing instance of type DisplayTermVectors is accessible" when calling Comparator... So to this function I p...
Hello, class Refvect { public: vector<int> &refv; Refvect(int t, vector<int> &refv = vector<int>()) : refv(refv) { }; void operator()() { refv.clear(); } }; int main () { Refvect r(0); r(); } With Visual Studio 2010, this gives me an error : "vector iterators incompatible" at the execution, but I d...
I have in an Object an QVector of Coordinates (my type) that i want to transfer to an other Vector ( i validate and than want to use ist ). Header bool getVector(QVector<Coordinates> &getCoordinates ); C File static QVector<Coordinates> current; int getVector( QVector<Coordinates> &getCoordinates) { .... stuff ... getCoordinat...
From a previous question about vector capacity, Mr. Bailey said: In current C++ you are guaranteed that no reallocation occurs after a call to reserve until an insertion would take the size beyond the value of the previous call to reserve. Before a call to reserve, or after a call to reserve when the size is between the value of the ...
I'm using Cygwin with GCC, and ultimately I want to read in a file of characters into a vector of characters, and using this code #include <fstream> #include <vector> #include <stdlib.h> using namespace std; int main (int argc, char *argv[] ) { vector<char> string1(); string1.push_back('a'); return 0; } generates this c...
Is that possible? I've seen no method that would generate a plain old C vector or array. I have just NSNumber objects in my array which I need as C vector or array. ...
I'm implementing an algorithm that involves lots of adding and removing things from sets. In R, this is slow because as far as I know, adding or removing things from a vector is slow, since the entire vector has to be re-allocated. Is there a way do do it more efficiently? Edit: My current solution is to use a boolean vector of the same...
I'm wrapping up user space linux socket functionality in some C++ for an embedded system (yes, this is probably reinventing the wheel again). I want to offer a read and write implementation using a vector. Doing the write is pretty easy, I can just pass &myvec[0] and avoid unnecessary copying. I'd like to do the same and read directly ...
test1 <- as.matrix(c(1, 2, 3, 4, 5)) row.names(test1) <- c("a", "d", "c", "b", "e") test2 <- as.matrix(c(6, 7, 8, 9, 10)) row.names(test2) <- c("e", "d", "c", "b", "a") test1 [,1] a 1 d 2 c 3 b 4 e 5 test2 [,1] e 6 d 7 c 8 b 9 a 10 How can I reorder test2 so that the rows are in the same order a...
I attempted to do something like this but it does not compile: class point { public: int x; int y; }; int main() { vector<point> vp1; vector<point> vp2; vector<point> vp3; map < vector<point>, int > m; m[vp1] = 1; m[vp2] = 2; m[vp3] = 3; map < vector<point>, int >::iterator it; ...
I have a vector of float arrays i.e. Vector . I want to convert this to one float array i.e. move every element in every float[] within the vector to a new float[]. Am a bit puzzled on using the Java built in method vector.toArray() to do this. Any ideas pls? ...