[R-sig-eco] glm(binomial) vs. logistf

[Drew Tyre]

After just a quick look I think one reason is that objects created with logistf() don't have as many methods for them. For example, I frequently use the predict() method with fitted models, and there is no predict method for logistf fits. Doesn't mean there couldn't be, but the code hasn't been written yet. 

-- 
Drew Tyre

School of Natural Resources
University of Nebraska-Lincoln
416 Hardin Hall, East Campus
3310 Holdrege Street
Lincoln, NE 68583-0974

phone: +1 402 472 4054 
fax: +1 402 472 2946
email: atyre2 at unl.edu
http://snr.unl.edu/tyre
http://aminpractice.blogspot.com
http://www.flickr.com/photos/atiretoo

-----Original Message-----
From: R-sig-ecology [mailto:r-sig-ecology-bounces at r-project.org] On Behalf Of Martin Weiser
Sent: Thursday, October 29, 2015 2:11 PM
To: r-sig-ecology at r-project.org
Subject: [R-sig-eco] glm(binomial) vs. logistf

Dear friends,

Is there any reason why to run logistic regression (binomial response) by glm() and not by logistf() by default? In particular when having sparse data (e.g. 8 presences in 100  samples), frequently with quasi-separation (all presences at one level of the predictor, together with many absences).

I tried to read some papers by G. Heinze - I did not get the whole thing, but it seems to me that both terms estimation and testing procedure should be more reliable using logistf(). Am I wrong? 

So, is there any reason why to use binomial glm?
I am sorry for my ignorance - there should be a reason why people stick to glm() - I just do not know what it is. Could you explain it to me or point me to something to read, please? I am not a statistician by training, however.

Thank you for your patience.

Kind regards,
Martin W.


  


-- 

------------------------------
Pokud je tento e-mail součástí obchodního jednání, Přírodovědecká fakulta Univerzity Karlovy v Praze:
a) si vyhrazuje právo jednání kdykoliv ukončit a to i bez uvedení důvodu,
b) stanovuje, že smlouva musí mít písemnou formu,
c) vylučuje přijetí nabídky s dodatkem či odchylkou,
d) stanovuje, že smlouva je uzavřena teprve výslovným dosažením shody na všech náležitostech smlouvy.

_______________________________________________
R-sig-ecology mailing list
R-sig-ecology at r-project.org
https://stat.ethz.ch/mailman/listinfo/r-sig-ecology