From holzer@stat.math.ethz.ch  Wed Jan  5 18:08:28 2000
From: holzer@stat.math.ethz.ch (holzer@stat.math.ethz.ch)
Date: Wed, 5 Jan 2000 19:08:28 +0100 (MET)
Subject: bug in glm.fit (PR#395)
Message-ID: <200001051808.TAA22156@pubhealth.ku.dk>

Dear R-team

There seems to be a bug in glm.fit - I got the following error message:

> > > + Error in names<-.default(*tmp*, value = ynames) : names attribute must be the same length as the vector
In addition: Warning messages: 
1: fitted probabilities of 0 or 1 occurred in: (if (is.empty.model(mt)) glm.fit.null else glm.fit)(x = X, y = Y,  
2: fitted probabilities of 0 or 1 occurred in: (if (is.empty.model(mt)) glm.fit.null else glm.fit)(x = X, y = Y,  
3: fitted probabilities of 0 or 1 occurred in: (if (is.empty.model(mt)) glm.fit.null else glm.fit)(x = X, y = Y,  
4: fitted probabilities of 0 or 1 occurred in: (if (is.empty.model(mt)) glm.fit.null else glm.fit)(x = X, y = Y,  
5: fitted probabilities of 0 or 1 occurred in: (if (is.empty.model(mt)) glm.fit.null else glm.fit)(x = X, y = Y,  
6: fitted probabilities of 0 or 1 occurred in: (if (is.empty.model(mt)) glm.fit.null else glm.fit)(x = X, y = Y,  
7: Algorithm did not converge in: (if (is.empty.model(mt)) glm.fit.null
else glm.fit)(x = X, y = Y,
  
> > traceback()
[1] "names<-.default(*tmp*, value = ynames)"                                  
[2] "names<-(*tmp*, value = ynames)"                                          
[3] "(if (is.empty.model(mt)) glm.fit.null else glm.fit)(x = X, y = Y, "      
[4] "    weights = weights, start = start, offset = offset, family = family, "
[5] "    control = control, intercept = attr(mt, \"intercept\") > 0)"         
[6] "glm(SKR.ein.aus ~ MWSQUAL + FAC.M1 + FAC.M2 + FAC.A1 + FAC.A2 + "        
[7] "    MLDR + TAGNR, family = binomial, data = daten[rows, ])"              


Debugging glm.fit I found the following: when some elements of the vector
`good' are FALSE then `w' has no more "full" length:

  w <- sqrt((weights * mu.eta.val^2)[good]/variance(mu)[good])

which leads to problems close to the end of the function:

  names(w) <- ynames

as `ynames' has "full" length.

The same problem is with:

  names(fit$effects) <- c(xxnames[seq(fit$rank)], rep("", nobs - 
        fit$rank))

as `fit$effects' has same length as `w'.

That's all I found out. I hope it helps.

I am sorry for not sending the data but as it is secret it would take some
effort to "disguise" it, so it that's not necessary I would be quite
grateful... 

Thanks, Peter

--please do not edit the information below--

Version:
 platform = i686-unknown-linux
 arch = i686
 os = linux
 system = i686, linux
 status = 
 major = 0
 minor = 90.1
 year = 1999
 month = December
 day = 15
 language = R

Search Path:
 .GlobalEnv, package:SfS, Autoloads, package:base

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bug in glm.fit (PR#395)
holzer@stat.math.ethz.ch