[R] Significant difference of coefficients in glm with factors?

From: Ghislain Vieilledent <ghislainv_at_gmail.com>
Date: Fri 22 Jul 2005 - 20:35:01 EST


Hi and sorry to distur,

########### Setting #################

I'm trying to use glm with factors:

> Pyr.1.glm<-glm(Pyrale~Trait,DataRav,family=poisson)
> summary(Pyr.1.glm)

Call:
glm(formula = Pyrale ~ Trait, family = poisson, data = DataRav)

Deviance Residuals:
Min 1Q Median 3Q Max
-1.7117 -0.8944 -0.6237 0.6390 1.5224

Coefficients:
Estimate Std. Error z value Pr(>|z|)
(Intercept) 1.3350 0.2294 5.819 5.92e-09 *** TraitIns&Fong -2.9444 1.0259 -2.870 0.00410 ** TraitInsecticide -2.2513 0.7434 -3.028 0.00246 ** TraitTemoin -0.2364 0.3454 -0.684 0.49372

---
Signif. codes: 0 `***' 0.001 `**' 0.01 `*' 0.05 `.' 0.1 ` ' 1 

(Dispersion parameter for poisson family taken to be 1)

Null deviance: 49.813 on 19 degrees of freedom
Residual deviance: 18.532 on 16 degrees of freedom
AIC: 61.85

Number of Fisher Scoring iterations: 5


> anova(Pyr.1.glm,test="Chisq")
Analysis of Deviance Table Model: poisson, link: log Response: Pyrale Terms added sequentially (first to last) Df Deviance Resid. Df Resid. Dev P(>|Chi|) NULL 19 49.813 Trait 3 31.281 16 18.532 7.419e-07 ############## Question ################## I would like to know if the coefficients for the levels of the factors are significatively different from each other and not only from the intercept. Do you know what function can I use and in which package can I found it? Thanks very much for you help. Regards. Ghislain V. -- Ghislain Vieilledent 30, rue Bernard Ortet 31 500 TOULOUSE 06 24 62 65 07 [[alternative HTML version deleted]] ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
Received on Fri Jul 22 21:06:14 2005

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