Simple usage of Eigen

The "<<" operator is overloaded in Eigen, and can be assigned either as an element or as a piece of value.

The number of rows, columns, and sizes of the current matrix can be obtained by rows (), cols () and size (), and the size of the matrix can be dynamically modified by the resize () function for the dynamic matrix.be aware that:(1) a fixed-size matrix cannot use resize () to modify the size of the matrix; (2) The resize () function will deconstruct the original data, so calling the resize () function does not guarantee that the value of the element will not change.
(3) when using the "=" operator to manipulate a dynamic matrix, the size of the left-hand dynamic matrix will be modified to the right size if the left-and side-edge matrix is of unequal size. For example, the following code snippet:

MATRIXXF A (2,2); Std::cout << "A is of size" << a.rows () << "x" << a.cols () << Std::endl; MATRIXXF b (3,3); a = B;std::cout << "A is now of size" << a.rows () << "x" << a.cols () << std :: Endl;

the rank, conjugate matrix and adjoint matrix of the matrix are obtained.

can be passed ,&NBSP; conjugate () Transposeinplace ()  ,  adjointinplace ()  .

MATRIXXCF a = Matrixxcf::random (2,2) cout << "Here's The Matrix a\n" << a << endl;cout << "Here I s The Matrix a^t\n "<< a.transpose () << endl;cout <<" Here is the conjugate of a\n "<< a.conjugate () << endl;cout << "Here is the Matrix a^*\n" << a.adjoint () << Endl;

Simple usage of Eigen