Block2x2

class numpy::Block2x2

numpy C++ class.

Example

#include <numpy/np_ndarray.h>
using namespace numpy;

// Use Block2x2
Block2x2 obj;
// ... operations ...

Constructors

Signature	Location	Example
Block2x2(size_tr, size_tc, Ta11_val, Ta12_val, Ta21_val, Ta22_val)	NP_LINALG.H:3333
Block2x2(const NDArray<T>&matrix, size_tr, size_tc)	NP_LINALG.H:3337

Linear Algebra

Signature	Return Type	Location	Example
T determinant()	T	NP_LINALG.H:3399
std::pair<std::complex<T>,std::complex<T>> eigenvalues()	std::pair<std::complex<T>,std::complex<T>>	NP_LINALG.H:3366
T norm()	T	NP_LINALG.H:3402	View
T trace()	T	NP_LINALG.H:3396	View

Type Checking

Signature	Return Type	Location	Example
bool is_complex_pair()	bool	NP_LINALG.H:3361

Other Methods

Signature	Return Type	Location	Example
void standardize()	void	NP_LINALG.H:3345
void write_to_matrix(NDArray<T>&matrix)	void	NP_LINALG.H:3388

Code Examples

The following examples are extracted from the test suite.

norm (np_test_1_all.cpp:7964)

void testComplex256FunctionsComplex256() {
    std::cout << "========= testComplex256FunctionsComplex256 =======================";

    complex256 z(3.0L, 4.0L);  // 3 + 4i

    // std::cout << "z = " << z << std::endl;
    // std::cout << "real(z) = " << z.real() << std::endl;
    // std::cout << "imag(z) = " << z.imag() << std::endl;
    // std::cout << "abs(z) = " << std::abs(z) << std::endl;
    // std::cout << "arg(z) = " << std::arg(z) << " radians" << std::endl;
    // std::cout << "norm(z) = " << std::norm(z) << std::endl;
    // std::cout << "conj(z) = " << std::conj(z) << std::endl;

    // Polar form
    auto magnitude = std::abs(z);
    auto phase = std::arg(z);
    auto polar_z = std::polar(magnitude, phase);
    // std::cout << "polar form: " << polar_z << std::endl;

    std::cout << " -> tests passed" << std::endl;
}

trace (np_test_2_all.cpp:4981)

      // Test transpose
      numpy::Matrix<double> m("1 2 3; 4 5 6");
      auto mt = m.transpose();
      assert_test(mt.rows() == 3, "Transpose rows");
      assert_test(mt.cols() == 2, "Transpose cols");
      assert_test(std::abs(mt(0, 1) - 4.0) < 1e-10, "Transpose element");
      assert_test(std::abs(mt(2, 0) - 3.0) < 1e-10, "Transpose element");

      // Test trace for square matrix
      numpy::Matrix<double> square("1 2; 3 4");
      double tr = square.trace();
      assert_test(std::abs(tr - 5.0) < 1e-10, "Matrix trace");

      // Test determinant for 2x2 matrix
      double det = square.det();
      assert_test(std::abs(det - (-2.0)) < 1e-10, "Matrix determinant 2x2");

      // Test matrix inverse for 2x2
      auto inv = square.inv();
      assert_test(std::abs(inv(0, 0) - (-2.0)) < 1e-10, "Matrix inverse 0,0");
      assert_test(std::abs(inv(0, 1) - 1.0) < 1e-10, "Matrix inverse 0,1");