eigen/MatrixBase__isIdentity_8cpp_source.html

 Matrix3d m = Matrix3d::Identity();

 m(0,2) = 1e-4;

 cout << "Here's the matrix m:" << endl << m << endl;

 cout << "m.isIdentity() returns: " << m.isIdentity() << endl;

 cout << "m.isIdentity(1e-3) returns: " << m.isIdentity(1e-3) << endl;

e
Array< double, 1, 3 > e(1./3., 0.5, 2.)

m
Matrix3d m
Definition: MatrixBase_isIdentity.cpp:1

Eigen::Matrix3d
Matrix< double, 3, 3 > Matrix3d
3×3 matrix of type double.
Definition: Matrix.h:502