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Fit Life by X

1304020094148

Community Trekker

Joined:

Sep 24, 2014

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!

1 ACCEPTED SOLUTION

Accepted Solutions
Solution

Thank you!  I'll give it a try!

3 REPLIES
peng_liu

Staff

Joined:

Jul 3, 2014

You 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.

Solution

Thank you!  I'll give it a try!

1304020094148

Community Trekker

Joined:

Sep 24, 2014

The 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.