Timeline for glmer model convergence question
Current License: CC BY-SA 4.0
5 events
| when toggle format | what | by | license | comment | |
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| May 9 at 8:03 | comment | added | Sextus Empiricus | Related Why does my Poisson regression fail? I'm using the R command glm(), x and y are non-negative integers, I'm using a linear link | |
| May 9 at 7:52 | comment | added | Sextus Empiricus | .... A problem might be when the model starts estimating the mean and variance as zero, then the weights become infinity. This is a bit similar to logistic regression breaking when there is perfect separation. | |
| May 9 at 7:50 | comment | added | Sextus Empiricus |
For certain values of the gamma function a support including zero should be ok, like the special case of an exponential distribution. A problem is maybe when the shape parameter is below 1. For a glm, which just models the mean and variance, it should also not matter. If one looks at the glm family object Gamma()[] then there is a stop at the initialisation if any of the values are non-positive. But if you manually remove this then the fitting is not influenced, except only for the case of conputing the AIC which makes a call to dgamma and can lead to infinity....
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| Jan 31, 2019 at 14:30 | review | First posts | |||
| Jan 31, 2019 at 15:43 | |||||
| Jan 31, 2019 at 14:29 | history | answered | sheen | CC BY-SA 4.0 |