C++ Armadillo :: any
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Description::
This is the basic C++ program of C++ armadillo library which returns true if vector V satisfies a relational condition. It can be carried out by the help of inbuilt function "any" in armadillo library.
- For vector V, return true if any element of the vector is non-zero or satisfies a relational condition
- For matrix X and
- dim=0, return a row vector (of type urowvec or umat), with each element (0 or 1) indicating whether the corresponding column of X has any non-zero elements
- dim=1, return a column vector (of type ucolvec or umat), with each element (0 or 1) indicating whether the corresponding row of X has any non-zero elements
- The dim argument is optional; by default dim=0 is used
- Relational operators can be used instead of V or X, eg. A > 0.9
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Program::
#include <iostream>
#include <armadillo>using namespace std;
using namespace arma;
int main()
{
vec V = randu<vec>(10);
mat X = randu<mat>(5,5);
// status1 will be set to true if vector V has any non-zero elements
bool status1 = any(V);
// status2 will be set to true if vector V has any elements greater than 0.5
bool status2 = any(V > 0.5);
// status3 will be set to true if matrix X has any elements greater than 0.6;
// note the use of vectorise()
bool status3 = any(vectorise(X) > 0.6);
// generate a row vector indicating which columns of X have elements greater than 0.7
umat A = any(X > 0.7);
cout << "Vector V::\n"<<endl;cout<< V << endl; cout << "Matrix X::\n"<<endl;
cout << X << endl; cout << "Status 1::\n"<<endl;
cout<< status1 << endl;
cout<< status2 << endl;
cout << "Status 3::\n"<<endl;
cout<< status3 << endl; return 0; }
cout<< status3 << 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::
Vector V::
0.7868
0.2505
0.7107
0.9467
0.0193
0.4049
0.2513
0.0227
0.5206
0.3447
Matrix X::
0.2742 0.8571 0.2393 0.1983 0.4599
0.5610 0.4998 0.3201 0.7159 0.2573
0.1400 0.4194 0.9105 0.9678 0.7770
0.5439 0.7443 0.1648 0.7694 0.5839
0.5219 0.2492 0.2455 0.0807 0.9503
Status 1::
1
Status 2::
1
Status 3::
1
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