Order to set the noise model

[Lu Gan]

I found two different order to set the noise model for prior pose. Could you tell me which one is correct? Also, how to check the order to set the bias noise model if I have different sigmas for accelerometer and gyroscope? Thanks!

ImuFactorExample

ImuFactorExample2

[Frank Dellaert]

There is no order. You set it before you use it. BTW this channel is for bug reports/issues, not usage questions :-) Please go to https://groups.google.com/forum/#!forum/gtsam-users for questions about use..

[Frank Dellaert]

Not a bug report

[Lu Gan]

Sorry. I mean in ImuFactorExample, the first three elements in sigmas vector are sigmas for rotation, the last three are sigmas for translation: noiseModel::Diagonal::shared_ptr pose_noise_model = noiseModel::Diagonal::Sigmas((Vector(6) << 0.01, 0.01, 0.01, 0.5, 0.5, 0.5).finished()); // rad,rad,rad,m, m, m Whereas in ImuFactorExample2, the first three are sigmas for translation, the last three are sigmas for rotation: auto noise = noiseModel::Diagonal::Sigmas( (Vector(6) << Vector3::Constant(0.3), Vector3::Constant(0.1)).finished());

Are those both correct? Or one of them is correct?

[Frank Dellaert]

Aha! Rotation comes first. I'll correct the comment in the second example.