C++ Armadillo :: cond
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Description::
This is the basic C++ program of C++ armadillo library which shows how to get the condition of matrix. It can be carried out by the help of inbuilt function "cond" in armadillo library. It takes one parameter i.e input matrix name.
- Return the condition number of matrix A (the ratio of the largest singular value to the smallest)
- Large condition numbers suggest that matrix A is nearly singular
- The computation is based on singular value decomposition; if the decomposition fails, a std::runtime_error exception is thrown
- The rcond() function is faster for providing an estimate of the reciprocal of the condition number
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Program::
#include <iostream>
#include <armadillo>using namespace std;
using namespace arma;
int main()
{
//initialize the random generator //Create a 5 x 5 random matrix and printing it
mat A = randu<mat>(5,5); //random matrix of size 5 x 5 (generared by this syntax)
double c = cond(A);
cout << "Matrix A::\n"<<endl;
cout<< A << endl;
return 0;
} cout << "Condition of Matrix ::\n"<<endl;
cout << c << endl;
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Commands to run program on terminal::
$ g++ filename.cpp -o objectname -O2 -larmadillo
$ ./objectname
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Output::
Matrix A::
0.7868 0.4049 0.2742 0.8571 0.2393
0.2505 0.2513 0.5610 0.4998 0.3201
0.7107 0.0227 0.1400 0.4194 0.9105
0.9467 0.5206 0.5439 0.7443 0.1648
0.0193 0.3447 0.5219 0.2492 0.2455
Condition of Matrix ::
21.0434
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