Yes, data is extremely skewed (as all AIDS behavioral data).
Thank you very much for time and solutions!
2011/3/13 Achim Zeileis achim.zeil...@uibk.ac.at
Ben,
thanks for your analysis...I also just sent a message with some similar
(and some different) ideas.
On Sun, 13 Mar 2011, Ben
On Sat, 12 Mar 2011, Vlatka Matkovic Puljic wrote:
Maybe I should include data:
As Ben said previously: The full data would have been more useful.
However, I've had a look at the response and even a regression with an
intercept only had the same problem.
R betareg(cond ~ 1, data =
Sorry, here is my data (attached).
2011/3/12 Ben Bolker bbol...@gmail.com
Vlatka Matkovic Puljic v.matkovic.puljic at gmail.com writes:
That was also my first thought.
But I guess it has something to do with W and phihat
(which I'm struggling to check
Again, it would help to post
http://dl.dropbox.com/u/21595123/Book1.csv
2011/3/13 David Winsemius dwinsem...@comcast.net
Nothing came through. You need to read the posting guide.
On Mar 13, 2011, at 12:59 PM, Vlatka Matkovic Puljic wrote:
Sorry, here is my data (attached).
2011/3/12 Ben Bolker bbol...@gmail.com
The problem seems to be that the algorithm for coming up with a
starting guess for the phi (dispersion) parameter is getting a negative
number. It's not all that easy to figure this out ... The data set is a
little bit nasty (lots of points stacked on the equivalent of (0,0)),
but not
On Sun, 13 Mar 2011, Vlatka Matkovic Puljic wrote:
http://dl.dropbox.com/u/21595123/Book1.csv
Thanks. As I suspected. Due to the many 0.001 values, the starting value
selection does not work well. In the development version of betareg() I've
added a more useful warning message and an ad hoc
Ben,
thanks for your analysis...I also just sent a message with some similar
(and some different) ideas.
On Sun, 13 Mar 2011, Ben Bolker wrote:
The problem seems to be that the algorithm for coming up with a
starting guess for the phi (dispersion) parameter is getting a negative
number.
Dear R users,
I'm trying to do betareg on my dataset.
Dependent variable is not normally distributed and is proportion (of condom
use (0,1)).
But I'm having problems:
gyl-betareg(cond ~ alcoh + drug, data=results)
Error in optim(par = start, fn = loglikfun, gr = gradfun, method = method, :
On Sat, 12 Mar 2011, Vlatka Matkovic Puljic wrote:
Dear R users,
I'm trying to do betareg on my dataset.
Dependent variable is not normally distributed and is proportion (of condom
use (0,1)).
But I'm having problems:
gyl-betareg(cond ~ alcoh + drug, data=results)
Error in optim(par = start,
Maybe I should include data:
results$cond
[1] 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001
[13] 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001
[25] 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001
[37] 0.001 0.001 0.020
Vlatka Matkovic Puljic v.matkovic.puljic at gmail.com writes:
Maybe I should include data:
results$cond
[1] 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001
[snip]
[205] 0.950 0.960 0.980 0.980 0.999
2011/3/12 Vlatka Matkovic Puljic v.matkovic.puljic at gmail.com
That was also my first thought.
But I guess it has something to do with W and phihat
(which I'm struggling to check?)
2011/3/12 Ben Bolker bbol...@gmail.com
Vlatka Matkovic Puljic v.matkovic.puljic at gmail.com writes:
My first guess would have been that you had zeros and ones in
Vlatka Matkovic Puljic v.matkovic.puljic at gmail.com writes:
That was also my first thought.
But I guess it has something to do with W and phihat
(which I'm struggling to check
Again, it would help to post a reproducible example ...
hard to debug/diagnose by remote control. If you
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