用Eigen库练习代数运算方式以便后续对刚体旋转和移动做基础

#include<iostream>
using namespace std;

#include<ctime>
#include<Eigen/Core>
#include<Eigen/Dense>
using namespace Eigen;
#define MATRIX_SIZE 50


int main (int argc,char **argv){
	Matrix<float,2,3>matrix_23;
	
	Vector3d v_3d;
	Matrix<float,3,1>vd_3d;
	Matrix3d matrix_33 = Matrix3d::Zero();
	Matrix <double,Dynamic,Dynamic>matrix_dynamic;
	MatrixXd matrix_x;
	
	
	matrix_23<<1,2,3,4,5,6;
	cout<<"matrix 2x3 from 1 to 6: \n"<<matrix_23<<endl;
	
	cout<<"print matrix 2x3:"<<endl;
	for(int i =0; i<2 ; i++){
		for(int j = 0;j<3 ; j++)cout<<matrix_23(i,j)<<"\t";
		cout<<endl;
	}
	
	v_3d<<3,2,1;
	vd_3d<<4,5,6;
	
	//Matrix<double, 2, 1>result_wrong_type = matrix_23 *v_3d;
	Matrix<double, 2, 1>result = matrix_23.cast<double>() * v_3d;
	cout<<"[1,2,3;4,5,6]*[3,2,1] = "<<result.transpose()<<endl;
	
	Matrix<float , 2, 1>result2 = matrix_23 * vd_3d;
	cout<<"[1,2,3;4,5,6]*[4,5,6] = "<<result2.transpose()<<endl;
	
	//Eigen::Matrix<double,2,3>result_wrong_dimension = matrix_23.cast<double>() *v_3d;
	
	
	matrix_33 = Matrix3d::Random();  //随机数矩阵
	cout<<"random matrix:\n "<<matrix_33<<endl;
	//注意逆和行列式需要声明<Eigen/Dense>
	cout<<"tranpose:\n"<<matrix_33.transpose()<<endl;//转置
	cout<<"sum:"<<matrix_33.sum()<<endl;	//各元素求和
	cout<<"trace:"<<matrix_33.trace()<<endl;
	cout<<"times 10"<< 10 * matrix_33<<endl;
	//cout << "inverse: \n" << matrix_33.inverse() << endl;        
 	//cout << "det: " << matrix_33.determinant() << endl;    


}