third_party/boost/numeric/ublas/examples/tensor/simple_expressions.cpp

//
//  Copyright (c) 2018-2019, Cem Bassoy, cem.bassoy@gmail.com
//
//  Distributed under the Boost Software License, Version 1.0. (See
//  accompanying file LICENSE_1_0.txt or copy at
//  http://www.boost.org/LICENSE_1_0.txt)
//
//  The authors gratefully acknowledge the support of
//  Fraunhofer IOSB, Ettlingen, Germany
//


#include <boost/numeric/ublas/tensor.hpp>
#include <boost/numeric/ublas/matrix.hpp>
#include <boost/numeric/ublas/vector.hpp>
#include <ostream>

int main()
{
	using namespace boost::numeric::ublas;

	using tensorf = tensor<float>;
	using matrixf = matrix<float>;
	using vectorf = vector<float>;

	auto A = tensorf{3,4,2};
	auto B = A = 2;

	// Calling overloaded operators
	// and using simple tensor expression templates.
	if( A != (B+1) )
		A += 2*B - 1;

	// formatted output
	std::cout << "% --------------------------- " << std::endl;
	std::cout << "% --------------------------- " << std::endl << std::endl;
	std::cout << "A=" << A << ";" << std::endl << std::endl;

	auto n = shape{3,4};
	auto D = matrixf(n[0],n[1],1);
	auto e = vectorf(n[1],1);
	auto f = vectorf(n[0],2);

	// Calling constructor with
	// vector expression templates
	tensorf C = 2*f;
	// formatted output
	std::cout << "% --------------------------- " << std::endl;
	std::cout << "% --------------------------- " << std::endl << std::endl;
	std::cout << "C=" << C << ";" << std::endl << std::endl;


	// Calling overloaded operators
	// and mixing simple tensor and matrix expression templates
	tensorf F = 3*C + 4*prod(2*D,e);

	// formatted output
	std::cout << "% --------------------------- " << std::endl;
	std::cout << "% --------------------------- " << std::endl << std::endl;
	std::cout << "F=" << F << ";" << std::endl << std::endl;


}