[Solved] The meaning of the

by


That is a shortcut for:

cv::Mat_<double> myMat_(3, 3);

myMat_.at(0, 0) = 1.0;
myMat_.at(0, 1) = 2.0;
myMat_.at(0, 2) = 3.0;

myMat_.at(1, 0) = 4.0;
myMat_.at(1, 1) = 5.0;
myMat_.at(1, 2) = 6.0;

myMat_.at(2, 0) = 7.0;
myMat_.at(2, 1) = 8.0;
myMat_.at(2, 2) = 9.0;

The << and the , operators are overloaded to implement that behavior.

solved The meaning of the << matrix operator