Dear John,

Thanks for your comments! But when I tried your suggestion, the output was as the following:


 Response Dist_arbre :
            Df     Sum Sq    Mean Sq F value    Pr(>F)    
Poids        1 0.00010398 0.00010398  6.2910 0.0364733 *  
Age          1 0.00005202 0.00005202  3.1476 0.1139652    
---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 

I have the P-value but not the direction of the relationship, information that I had with  "lm(as.matrix(Y) ~  x+z)". I could combine the results of these two tests, but it seems inelegant to me. Moreover I didn't have a total significance test as with a true MANCOVA. 

An idea?!

Rémi Lesmerises, biol. M.Sc.,
Candidat Ph.D. en Biologie
Université du Québec à Rimouski
300, allée des Ursulines
remilesmerises@yahoo.ca



________________________________
 De : John Fox <jfox@mcmaster.ca>
À : Rémi Lesmerises <remilesmerises@yahoo.ca> 
Cc : "r-help@r-project.org" <r-help@r-project.org> 
Envoyé le : mercredi 17 avril 2013 10h54
Objet : Re: [R] Mancova with R


Dear Remi,

Take a look at the Anova() function in the car package. In your case, you could use

Anova(lm(as.matrix(Y) ~  x + z))

or, for more detail,

summary(Anova(lm(as.matrix(Y) ~  x + z)))

I hope this helps,
John

------------------------------------------------
John Fox
Sen. William McMaster Prof. of Social Statistics
Department of Sociology
McMaster University
Hamilton, Ontario, Canada
http://socserv.mcmaster.ca/jfox/
    
On Wed, 17 Apr 2013 07:47:27 -0700 (PDT)
Rémi Lesmerises <remilesmerises@yahoo.ca> wrote:
> Dear all,
> 
> I'm trying to compare two sets of variables, the first set is composed exclusively of numerical variables and the second regroups factors and numerical variables. I can't use a Manova because of this inclusion of numerical variables in the second set. The solution should be to perform a Mancova, but I didn't find any package that allow this type of test.
> 
> I've already looked in this forum and on the net to find answers, but the only thing I've found is the following:
> 
> 
> lm(as.matrix(Y) ~  x+z)
> x and z could be numerical and factors. The problem with that is it actually only perform a succession of lm (or glm), one for each numerical variable contained in the Y matrix. It is not a true MANCOVA that do a significance test (most often a Wald test) for the overall two sets comparison. Such a test is available in SPSS and SAS, but I really want to stay in R! Someone have any idea?
> 
> Thanks in advance for your help!
>  
> Rémi Lesmerises, biol. M.Sc.,
> Candidat Ph.D. en Biologie
> Université du Québec à Rimouski
> remilesmerises@yahoo.ca
> 
>     [[alternative HTML version deleted]]
> 
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