comparison armadillo-2.4.4/examples/example2.cpp @ 0:8b6102e2a9b0

Armadillo Library

+#include <iostream>
+
+#include "armadillo"
+
+using namespace arma;
+using namespace std;
+
+
+int main(int argc, char** argv)
+  {
+  cout << "Armadillo version: " << arma_version::as_string() << endl;
+  
+  mat A;
+  
+  A << 0.165300 << 0.454037 << 0.995795 << 0.124098 << 0.047084 << endr
+    << 0.688782 << 0.036549 << 0.552848 << 0.937664 << 0.866401 << endr
+    << 0.348740 << 0.479388 << 0.506228 << 0.145673 << 0.491547 << endr
+    << 0.148678 << 0.682258 << 0.571154 << 0.874724 << 0.444632 << endr
+    << 0.245726 << 0.595218 << 0.409327 << 0.367827 << 0.385736 << endr;
+  
+  A.print("A =");
+  
+  // determinant
+  cout << "det(A) = " << det(A) << endl;
+  
+  // inverse
+  cout << "inv(A) = " << endl << inv(A) << endl;
+  
+  
+  //
+  
+  double k = 1.23;
+  
+  mat    B = randu<mat>(5,5);
+  mat    C = randu<mat>(5,5);
+  
+  rowvec r = randu<rowvec>(5);
+  colvec q = randu<colvec>(5);
+  
+  
+  // examples of some expressions
+  // for which optimised implementations exist
+  
+  // optimised implementation of a trinary expression
+  // that results in a scalar
+  cout << "as_scalar( r*inv(diagmat(B))*q ) = ";
+  cout << as_scalar( r*inv(diagmat(B))*q ) << endl;
+  
+  // example of an expression which is optimised 
+  // as a call to the dgemm() function in BLAS:
+  cout << "k*trans(B)*C = " << endl << k*trans(B)*C;
+  
+  
+  // If you want to see a trace of how Armadillo
+  // evaluates expressions, compile with the
+  // ARMA_EXTRA_DEBUG macro defined.
+  // This was designed to work with the GCC compiler,
+  // but it may also work with other compilers
+  // if you have the Boost libraries installed
+  // and told Armadillo to use them.
+  // 
+  // Example for GCC:
+  // g++ example2.cpp -o example2 -larmadillo -DARMA_EXTRA_DEBUG
+  // 
+  // Running example2 will now produce a truckload of messages,
+  // so you may want to redirect the output to a log file.
+  
+  return 0;
+  }
+