BookmarkSubscribe
Choose Language Hide Translation Bar
ptolomey
Community Trekker

Separate Location parameters using Parametric Survival platform

Hi All,

I am trying to predict hazard rate and MTTF with Eyring model (see attached file). 

Screenshot from 2018-11-13 20-26-02.png

 

 

 

Using Parametric Survival platform.

 

Parametric Survival Dialog.jpg

 

In Parameter Estimates report there is scale parameter "sigma" but no separate location parameters for Loglogistic distribution.

 

Parameters Estimates.jpg

 

Only graphic representation of separate location and separate location & scale are given in Parametric Survival platform.

 

Graphic Representation.jpg

 

 Is there way to get values of separate location parameters for chosen probabilistic distribution?

0 Kudos
1 ACCEPTED SOLUTION

Accepted Solutions

Re: Separate Location parameters using Parametric Survival platform

So, use the parameter estimates to compute the Location parameter for each of the conditions:

Location = -7.2947 + 0.533 * Arrhenius(Temp) + -1.11 * Log(Voltage)
Learn it once, use it forever!
0 Kudos
4 REPLIES 4

Re: Separate Location parameters using Parametric Survival platform

The location is not constant like the scale. The location parameter is the back transformed function of the linear predictor.

Learn it once, use it forever!
0 Kudos
ptolomey
Community Trekker

Re: Separate Location parameters using Parametric Survival platform

Hi Mark.

Thank you for reply.

I made same analysis in Minitab Accelerated Life Testing plaform.


Dialog.jpg

 

 

In the report there is Location parameter for each Temperature-Voltage pair.

By the way vaue of Scale parameter in Minitab is mutches value of same parameter in JMP 0.34

 

 

Report Graph.jpg

0 Kudos

Re: Separate Location parameters using Parametric Survival platform

So, use the parameter estimates to compute the Location parameter for each of the conditions:

Location = -7.2947 + 0.533 * Arrhenius(Temp) + -1.11 * Log(Voltage)
Learn it once, use it forever!
0 Kudos
ptolomey
Community Trekker

Re: Separate Location parameters using Parametric Survival platform

Hi Mark,

You absolutely right.

For standardized Loglogistic distribution: Location = Ln(T50)

 

Thank you.

 

 

 

0 Kudos