drop1: warning message
No idea, you may want to tell us all your calls and give a reproducible example as well as properly formatted code that is more readable than the stuff below. I guess you omitted some other warnings that tell you about too few obervations to fit the model (the "fitted probabilities numerically 0 or 1 occurred" is a weak indication that your model may be overspecified). Best, Uwe Ligges
On 12.01.2010 08:17, Martin Bulla wrote:
Dear R collegues, I am new to R and do not understad the warning messages, which appear when I am trying to apply type III procedure to my glm:
inkm$Gamie glm.inkmZ drop1(glm.inkmZ,test="Ch")
Single term deletions
Model:
InkMb ~ IncStart + Vol + Gamie + PC1 + PC2 + PC3 + SpotsN + PC1:SpotsN
Df Deviance AIC LRT Pr(Chi) 9.3879
27.388 IncStart 1 14.6274 30.627 5.2395
0.0220791 * Vol 1 15.9723 31.972 6.5844 0.0102876 *
Gamie 1 13.8659 29.866 4.4780 0.0343330 * PC2 1
9.6899 25.690 0.3020 0.5826585 PC3 1 10.7326 26.733 1.3447
0.2462124 PC1:SpotsN 1 21.6517 37.652 12.2638 0.0004618 ***
---
Signif. codes: 0 ?***? 0.001 ?**? 0.01 ?*? 0.05 ?.? 0.1 ? ? 1 Warning
messages:
1: In glm.fit(x[, jj, drop = FALSE], y, wt, offset = object$offset, :
fitted probabilities numerically 0 or 1 occurred
2: In glm.fit(x[, jj, drop = FALSE], y, wt, offset = object$offset, :
fitted probabilities numerically 0 or 1 occurred
Where did PC1 disappiered? What is the meaning of these warning messages?
Similarly, I do not understand where did PCs dissapeared in the
following calculations:
inkm$Gamie glm.inkm0 drop1(glm.inkm0,test="Ch")
Single term deletions
Model:
InkMb ~ IncStart + Vol + Gamie + PC1 + PC2 + PC3 + SpotsN + Gamie:PC1 +
Gamie:PC2 + Gamie:PC3
Df Deviance AIC LRT Pr(Chi) 18.368
40.368 IncStart 1 26.078 46.078 7.7106 0.005490 **
Vol 1 26.515 46.515 8.1475 0.004312 **
SpotsN 1 18.663 38.664 0.2958 0.586537 Gamie:PC1 1 20.418
40.418 2.0505 0.152155 Gamie:PC2 1 18.460 38.460 0.0919 0.761818
Gamie:PC3 1 19.832 39.832 1.4647 0.226180 ---
Any suggestions would help me greatly.
Best regards,
Martin
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