$rot_mat1=eul2mat($data_doc1[$i],$data_doc1[$i+1],$data_doc1[$i+2]); #Catch the reference to the first matrix $rot_mat2=eul2mat($data_doc2[$i],$data_doc2[$i+1],$data_doc2[$i+2]); #Catch the reference to the second matrix $cbn_mat=mat_multiply($rot_mat1,$rot_mat2); #Multiply the two matrices @cbn_angles=mat2eul($cbn_mat); #Convert the matrix back to euler sub eul2mat { my $phi_rad=deg2rad($_[0]); my $theta_rad=deg2rad($_[1]); my $psi_rad=deg2rad($_[2]); #print "$phi_rad $theta_rad $psi_rad\n"; my @rot_mat; $rot_mat[0][0]=cos($phi_rad)*cos($theta_rad)*cos($psi_rad)-sin($phi_rad)*sin($psi_rad); $rot_mat[0][1]=cos($phi_rad)*cos($theta_rad)*sin($psi_rad)+sin($phi_rad)*cos($psi_rad); $rot_mat[0][2]=-cos($phi_rad)*sin($theta_rad); $rot_mat[1][0]=-sin($phi_rad)*cos($theta_rad)*cos($psi_rad)-sin($psi_rad)*cos($phi_rad); $rot_mat[1][1]=-sin($phi_rad)*cos($theta_rad)*sin($psi_rad)+cos($phi_rad)*cos($psi_rad); $rot_mat[1][2]=sin($phi_rad)*sin($theta_rad); $rot_mat[2][0]=sin($theta_rad)*cos($psi_rad); $rot_mat[2][1]=sin($theta_rad)*sin($psi_rad); $rot_mat[2][2]=cos($theta_rad); say Dumper \@rot_mat; return \@rot_mat; } sub mat_multiply { my ($mat1,$mat2)=@_; my ($i,$j,$k); my $result_mat=[]; for $i (0..2) { for $j (0..2) { for $k (0..2) { $result_mat->[$i][$j]+=$mat1->[$i][$k] * $mat2->[$k][$j]; } } } return $result_mat; } sub mat2eul { print "$_[2][0]\n"; my $theta_deg=rad2deg(atan2((sqrt($_[2][0]**2+$_[2][1]**2)),$_[2][2])); my $phi_deg=rad2deg(atan2(($_[1][2]/sin(deg2rad($theta_deg))),(-$_[0][2]/sin(deg2rad($theta_deg))))); my $psi_deg=rad2deg(atan2(($_[2][1]/sin(deg2rad($theta_deg))),($_[2][0]/sin(deg2rad($theta_deg))))); return ($theta_deg,$phi_deg,$psi_deg); }