LEDA Guide: Example Vectors and Matrices with Integer Entries

Algorithmic Solutions > LEDA > LEDA Guide > Number Types > Vectors and Matrices with Integer Entries > Example

Example Vectors and Matrices with Integer Entries

The following example shows the usage of vectors and matrices with Integer entries. In the first part, two vectors are defined and two operations for vectors are illlustrated. The second part shows matrices and some of their operations.

#include <LEDA/numbers/integer_vector.h>
#include <LEDA/numbers/integer_matrix.h>
#include <LEDA/core/random_source.h>

using namespace leda;

int main() 
{
  //integer valued vectors

  integer_vector v1(3),v2(3);  //define two 3d-zero-vectors;
  v1=integer_vector(1,2,3);    //assign values
  v2=integer_vector(3,4,5);

  v1=v1*integer(3);   //componentwise multiplication with 3

  integer x=v1*v2;    //scalar multiplication

  std::cout << "vector v1=" << v1 << std::endl;
  std::cout << "vector v2=" << v2 << std::endl;
  std::cout << "product v1*v2="   << x << std::endl;
  
  //-------------------------------------------------------
 
  //integer valued matrices
  
  integer_matrix A(3,3); //define 3x3-matrix 

  random_source S; int i;int j;  
  for (i=0;i<3;i++) for (j=0;j<3;j++) S >> A(i,j);
                                  //assign random values

  std::cout << "\nA=" << A << std::endl;    //print A
  std::cout << "\nA^T=" 
            << transpose(A) << std::endl;   //compute and print transposed of A
  std::cout << "\ndeterminant of A: " 
            << determinant(A) << std::endl; //compute and output determinant of A

  integer_matrix B(3,6); //define 3x6-zero-matrix and assign values
  for (i=0;i<3;i++) for (j=0;j<6;j++) B(i,j)=i-j-1;

  std::cout << "\nB=" << B << std::endl;  //print B

  integer_matrix C=A*3; //multiplication of matrix with double
  std::cout << "\nC=A*3: " << C << std::endl;

  v2=A*v1;              //multiplication of matrix with vector
  std::cout << "\nvector v2=A*v1: " << v2 << std::endl;

  C=A*B;                //multiplication of two matrices
  std::cout << "\nC=A*B: " << C << std::endl;

  return 0;
}

Example Vectors and Matrices with Integer Entries

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