C++ :: How To Create A Large Matrix To Be Solved Using Numerical Methods
Jun 24, 2013
I am having a problem on how will I create a large matrix to be solved using numerical methods. Say I have a 500 x 500 matrix and want to find these 500 equations. How will I do it? To be exact, here is a sample problem
Solutions on finding would be gauss elimination, Successive overrelaxation, Jacobi Iteration, biconjugate gradient method and Thomas algorithm. I want to compare the accuracy, with tolerance of 10^-6
I have this assignment where I have to create a map based hash table for a sparse matrix. The professor has provided some code and I'm supposed to fill in parts of it to make it work.
He has given us a class sparseMatrix which we need to provide a hash function for. This hash function is to be defined in a Class TupleHash which is inside sparseMatrix. I think I got that part down. What is really confusing me is what he has done with some typedefs.
For one of them I had to declare an unorderd_map that maps a struct Tuple on to the class template argument Object. I did that like so:
This is giving me a world of unintelligible error messages. This is how it starts.
In instantiation of 'struct std::__detail::__is_noexcept_hash<int, sparseMatrix<int>::TupleHash>':| recursively required from 'struct std::__and_<std::is_default_constructible<sparseMatrix<int>::TupleHash>, std::is_copy_assignable<sparseMatrix<int>::TupleHash>, std::__detail::__is_noexcept_hash<int, sparseMatrix<int>::TupleHash> >'|
Ok I'm trying to create matrix of data that I can add values to based on a reading that I will get from a DVM. I'm using a 3d vector to do this. I need to keep track of the serial number, the day and within day I need to take two readings at different temps, this will continue for 7 days.
The rows of my 3d vector will be the days, the colums will be the serial numbers the depth will be the reading at the different temps.
What I need to do is compare the first element (days) and when it is greater then or equal to 4 I will perform calculations of the readings. So all I want to do is compare the first element of the vector, How do I do this?
I am looking for C-libraries that would do numerical tasks with special emphasis on numerical differentiation of arbitrary order, numerical integration (Monte Carlo etc.) and interpolation. I would be grateful if you can provide me with some resources. By the way I already have Numerical Recipes but would like to have another resource at hand.
im trying to make a statistics program and i have an array holding all the users numbers. The array has 10 elements and i was wondering how i could put these elements in order from smallest to largest.
I need to find the Mean, median, mode, and make a histogram of a 99 value array. How ever my sorting function is not sorting the array at all how can I fix this.
I have the problem of trying to find the smallest natural number that makes two consecutive terms in single precision floating point notation in the riemann zeta function equal. So basically the riemann function of 2 is given by:
sum of 1/(k^2) from k=1 until infinity, so : 1/(1^2) + 1/(2^2) + 1/(3^2) + ...... until infinity.
Now the question asks to stop at the smallest natural number n, at which the sum 1/1^2 + 1/2^2 + ......+ 1/(n^2) is equal to the sum 1/1^2 + 1/2^2 + ..... + 1/((n+1)^2) in single precision floating point notation.
Now well the obvious way to look for n would be on this way:
float i = 1.0; float n = 1/(i); float n1 = 1/(i+1.0); while ( n != n1){ i += 1.0; n = 1/i; n1 = 1/(i+1.0);}
But first of all this is obviously completely inefficient and I dont think it will yield a valid answer for any float variable, i.e. I dont think the sum until 1/n^2 and 1/(n+1)^2 will ever differ. I tried it out with the largest possible value of a variable of type float and the values were still seen as unequal in C++. How to do this? Will C++ find a value for n for which the condition holds? Is the compiler or my hardware important for this, i.e. would I get different results on a different pc?
I what to implement to my Template operator * . There is <Template> Array which purpose is container like vector for classes. There is class Point, each object of contain two coordinate x and y.
So, 1. I wanna fill Array with objects from Point class 2. Multiply each objects from this vector to a factor 3. And print all this bunch of objects ()...
And pop -up helper tell that : Error: no suitable user defined conversion from "Point " to Array<Point> exist
Code: //array.h #ifndef Array_H #define Array_H template <class Type> //Remove the "=double" default parameter. class Array { protected: int m_size; Type* m_data; //m_data should be a pointer, since you want to allocate data to it
I just want to know the code of the program: Write code to accept matrix as aurgument and display its multiplication matrix which return its multiplication matrix.
I have to code a simple program who determining the number of Characters (A character could be any alphabets, digits, punctuation marks, or special , Operators ( Operators are those symbols that are used in mathematica expression, such as,'+', '*', '/', '-', and so on.), Uppercase letters (Uppercase characters are those from A..Z) and Numerical digits ( A digit is any of the Hindu-Arabic numerals from 0..9). Why the output is wrong!
#include <iostream> #include <string> #include <fstream> #include <cstdlib> #include <iomanip> using namespace std ; int main() { char text;
[Code] .....
This is my input file This is a possible factorial function in a programming language called LISP
(defun factorial (n) (if (< n 2) 1 (* n (factorial (1- n)))))
This is my output:
The number of characters = 113 The number of operators = 3 The number of numerical digits = 3 Uppercase letters = 5
I think that "characters" is wrong, but I do not know why !
but if the matrix is compressed_matrix type, there's something with it. the error log as below:
Check failed in file boost_1_48_0/boost/numeric/ublas/detail/matrix_assign.hpp at line 1078: detail::expression_type_check (m, cm) terminate called after throwing an instance of 'boost::numeric::ublas::external_logic' what(): external logic Aborted
I have to write a function called sortMe that sorts the elements of an array in numerical order from highest to lowest values (descending order) or vice versa (ascending order).
The assignment asks to: NOT re-arrange elements in the array; instead, it uses a second array, an array of indexes for the elements in the original array and then sortMe sorts the second array based on the values in the original array. A sorted version of the original array can then be produced with these sorted indexes.
Header of the function sortMe must be as shown below:
void sortMe(int array[],int sortedIndexes [], int size, char mode)
When mode is 'a', the function sorts the array in the ascending order, and when mode is 'd', the function sorts it in the descending order.
Declare and initialize the array array.
Declare the array sortedIndexes but do not initialize it. You are going to play with the array sortedIndexes in the function sortMe.
EXAMPLE:
int array[5]={3, 5,-1,10,0}; int sortedIndexes[5]; sortMe(array,sortedIndexes, 5, 'a');
After the function call, the elements of the array sortedIndexes should be: 2,4,0,1,3.
notice that the function does not e-arrange the elements in the array.
I have questions about multiple inheritance and virtual methods. I have a class called solid. All objects of this class have hitboxes and can collide with others. I have the following methods:
void testCollision(something begin, something end); /* This method takes a container's begin and end iterators to test if the object collides with any other object of the list of all the solids currently in the game area. Each time there is a collision, it calls collide(other) and other.collide(*this) */
virtual bool collide(solid& other); /* This method always returns false and does nothing */
This class will be inherited by another class which will have overloads for a few specific collisions. For example:
class player : public solid{ public: bool collide(projectile& other); bool collide(enemy& other); bool collide(wall& other); };
My question is quite simple actually. If I have a loop which calls testCollision() with all elements in the list of all solids (a list of pointers to solids to be exact) and there is a collision between the player and a projectile, will testCollision call player::colide(projectile& other) or will it call solid::collide(solid& other). And in any case, did I understand how to use the virtual keyword? If I'm right, it should call the player::colide method if it's there for the specific type, else it will call the solid::colide which only returns 0, ignoring collision.
I have h-file with definition of 3 classes. And cpp-file with realization methods of this classes. And when I compile the project errors - LNK2019 is apperead... How make that methods become visible?
I'm writing a sorted vector implementation and trying to do it as simply as possible.
Right now, I'm declaring the sorted vector with a protected subclass of vector, then using the "using" keyword to explicitly inherit all methods that aren't related to adding new elements to the vector (so I can control the order).
Eg:
Code: template<typename T, class Cmp = std::less<T>> class sorted_vector : protected std::vector<T>{ public: typedef typename std::vector<T>::iterator; using std::vector<T>::operator=; using std::vector<T>::assign; using std::vector<T>::get_allocator; using std::vector<T>::at; using std::vector<T>::operator[]; //... };
Obviously, this is annoyingly redundant. So what I'd like to do is something using the new "delete" keyword from C++11. Is there any quick, expressive way of deleting specific methods?
Also, it's pretty annoying to have to typedef base_class::type type to inherit a type from a base class. Is there a shorter way to do that?
I'd like to be able to add additional class-methods through lua for any classes that I've bound in c++, but I'm unsure how to do it.
The problem is that luabind uses a function as the __index-metamethod for any bound classes instead of a table, so I don't see a way to access the class-methods at all.
What I essentially want to do is to add a lua-function to the list of methods for this class, and be able to overwrite existing ones:
local t = tableOfClassMethods local r = t.TestFunc -- Reference to the c++-function we've bound t.SomeFunction = function(o) end -- New function for all objects of this class t.TestFunc = function(o) end -- Should overwrite the c++-function of the same name
