I'm using the following equation to invert (non-linearly) for three parameters, L Vr and f.

$$T_r=\frac{L}{V_r} - \frac{(L\,\cos( \theta )\,\cos( \alpha - f))}{V} $$

I have observational errors on $T_r$ which can be dealt with using weighting in the LM algorithms in Matlab, but how do I deal with the errors in my three variables V, $\alpha$ and $\theta$?

I'm looking to get a value for my three parameters ($L$, $V_r$ and $f$) and 95% confidence limits.

  • $\begingroup$ Take a look at en.wikipedia.org/wiki/Total_least_squares . $\endgroup$ – Mark L. Stone Jun 29 '17 at 15:02
  • $\begingroup$ It looks like you have a non-linear errors-in-variables problem. In respect of the remaining symbols, please clarify their role -- are they variables without observational error, constants, parameters to be estimated? I'm guessing $L$ $f$ and $V_r$ are meant to be parameters to be estimated but you should be explicit. (Additional information is likely to be required as well.) $\endgroup$ – Glen_b Jun 30 '17 at 0:12
  • $\begingroup$ No problem I'll edit above, V, alpha and theta are meant to be variables in the equation with some error associated with them and I want to see how much of a difference it makes to L, Vr and f. $\endgroup$ – Whitt Jun 30 '17 at 8:41

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.