Fit Life by X<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />Can anyone suggest a way to run "Fit Life by X" when the form is
mu (log lifetime) = beta0 + X^(beta1)?
From running the reciprocal and custom relations, beta1 values between -1 and -2 seems to give the best fit to the observed failure times.
Many thanks!
Re: Fit Life by XDr. Bill Meeker also pointed out that this model's parameters can also be obtained, in a different form, by using the Box-Cox relationship in the Fit Life By X platform and then using the distribution results sensitivity profiler to maximize lambda's likelihood and then re-running Box-Cox with that lambda. (Thanks Dr. Meeker!)Re: Fit Life by XThe Nonlinear Model platform seems to work well. Carrying this beyond the original question, it looks as though I would need to create a 'dummy' X variable in order to combine two factors, e.g. Peck's Power-law humidity model.
Re: Fit Life by XThank you! I'll give it a try!
Re: Fit Life by XYou cannot. Fit Life by X assumes the formula for mu is linear in beta's. I don't see whether this model has an equivalent form which is linear in beta's. I would suggest using Nonlinear to solve the problem.
