Can't Figure out Logic Error involving Setting Rotation Matrix - opencv

Question

I'm trying to extract the 3x3 rotation matrix from the 3x4 pose matrix I have. However, two values are differing even though I have very simple code setting one to the other. I'm banging my head against the wall because I have no idea why this is happening. Here is the code:
std::cout << "Camera pose matrix from optical flow homography" << std::endl;
for (int e = 0; e < pose.rows; e++) {
for (int f = 0; f < pose.cols; f++) {
std::cout << pose.at<double>(e,f) << " " << e << " " << f;
std::cout << " ";
}
std::cout << "\n" << std::endl;
}
std::cout << "Creating rotation matrix" << std::endl;
Mat rotvec = Mat::eye(3, 3, CV_32FC1);
for (int s = 0; s < pose.rows; s++) {
for (int g = 0; g < pose.cols-1; g++) {
rotvec.at<double>(s, g) = pose.at<double>(s,g);
std::cout << rotvec.at<double>(s,g) << " " << s << " " << g;
std::cout << " ";
}
std::cout << "\n" << std::endl;
}
std::cout << "Rotation matrix" << std::endl;
for (int e = 0; e < pose.rows; e++) {
for (int f = 0; f < pose.cols-1; f++) {
std::cout << rotvec.at<double>(e,f) << " " << e << " " << f;
std::cout << " ";
std::cout << pose.at<double>(e,f) << " " << e << " " << f;
std::cout << " ";
}
std::cout << "\n" << std::endl;
}
Here is the output:
Camera pose matrix from optical flow homography
5.26354e-315 0 0 0 0 1 0.0078125 0 2 0 0 3
0.0078125 1 0 0 1 1 0 1 2 5.26354e-315 1 3
0 2 0 5.26354e-315 2 1 1.97626e-323 2 2 7.64868e-309 2 3
Creating rotation matrix
5.26354e-315 0 0 0 0 1 0.0078125 0 2
0.0078125 1 0 0 1 1 0 1 2
0 2 0 5.26354e-315 2 1 1.97626e-323 2 2
Rotation matrix
5.26354e-315 0 0 5.26354e-315 0 0 0 0 1 0 0 1 5.26354e-315 0 2 0.0078125 0 2
0.0078125 1 0 0.0078125 1 0 0 1 1 0 1 1 0.0078125 1 2 0 1 2
0 2 0 0 2 0 5.26354e-315 2 1 5.26354e-315 2 1 1.97626e-323 2 2 1.97626e-323 2 2
Here you can see I'm trying to save the first three columns of pose into the rotvec matrix. When I actually set the rotation matrix equal to the pose for those three columns, I get the correct matrix, as the second matrix is equal to the first three columns of the first matrix. However, when I check the rotation matrix once again, (third matrix) it is not the same as the output I require on coordinates (0, 2) and (1, 2). (I outputted the rotvec matrix number next to the pose matrix number, and you can see at these coordinates the numbers do not match). I am not sure why this is happening, could someone please help me out?

Answer 1

Solved my problem for anyone else who stumbles upon this later: I just changed the Mat type to CV_64F (to make it double) for both rotvec and pose, and used all to display. Creds to berak for pointing me in the right direction.