C++ Armadillo :: find_nonfinite
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Description::
This is the basic C++ program of C++ armadillo library which shows how to get the element of matrix which are non finite numbers. It can be carried out by the help of inbuilt function "find_nonfinite" in armadillo library. It takes one parameter i.e input matrix name.
- Return a column vector containing the indices of elements of X that are non-finite (ie. ±Inf or NaN)
- The output vector must have the type uvec (ie. the indices are stored as unsigned integers of type uword)
- X is interpreted as a vector, with column-by-column ordering of the elements of X
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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)
A(1,1) = datum::inf; //replacing values at (1,1) and (2,2) of matrix A
A(2,2) = datum::nan;
uvec indices = find_nonfinite(A);
cout << "Matrix A::\n"<<endl;
cout<< A << endl;
cout << "Vector indices::\n"<<endl;
cout << indices << endl;
A.elem( find_nonfinite(A) ).zeros(); //making non finite elements zero and displaying
cout << "Matrix A::\n"<<endl; cout<< A << endl;
return 0;
}
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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 inf 0.5610 0.4998 0.3201
0.7107 0.0227 nan 0.4194 0.9105
0.9467 0.5206 0.5439 0.7443 0.1648
0.0193 0.3447 0.5219 0.2492 0.2455
Vector indices::
6
12
Matrix A::
0.7868 0.4049 0.2742 0.8571 0.2393
0.2505 0 0.5610 0.4998 0.3201
0.7107 0.0227 0 0.4194 0.9105
0.9467 0.5206 0.5439 0.7443 0.1648
0.0193 0.3447 0.5219 0.2492 0.2455
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