[R] cov.mve error

2010-11-02 Thread Marino Taussig De Bodonia, Agnese
Hello, I am trying to use the cov.mve function on a set of variables to check for outliers, before I perform PCA on them. I am using the code that I found on Everitt (2005) An R ans S-Plus companion to multivariate analysis but its doesn't seem to work. I wrote: at.central-central[,7:17]

[R] package MuMI

2010-08-25 Thread Marino Taussig De Bodonia, Agnese
Hello, I am using the package MuMI to run all the possible combinations of variables in my full model, and select my best models. When I enter my variables in the original model I write them like this lm(y~ a +b +c +a:b) However, MuMI will also use the variable b:a, which I do not want in my

[R] chisq.test on samples of different lengths

2010-08-24 Thread Marino Taussig De Bodonia, Agnese
Hello, I am trying to see whether there has been a significant difference in whether people experienced damages from wildlife in two different years. I therefore have two columns: year 1: yes no no no yes yes no year 2: no yes no yes I wanted to do a chisq.test, but if I enter it this way:

[R] glmulti: defining which intractions between variables are to be included

2010-08-03 Thread Marino Taussig De Bodonia, Agnese
Hello, I'm using the glmulti package to run models of all the possible combinations of my variables. However, I am only interested in a few interactions between my variables. I have tried the equivalent of: mod1-lm(y~a+b+c+a:b) glmulti(mod1, level=1) mod2-lm(y~a+b+c+a:b) glmulti(mod2,

[R] FW: glmulti: defining which intractions between variables are to be included

2010-08-03 Thread Marino Taussig De Bodonia, Agnese
Hello, I'm using the glmulti package to run models of all the possible combinations of my variables. However, I am only interested in a few interactions between my variables. I have tried the equivalent of: mod1-lm(y~a+b+c+a:b) glmulti(mod1, level=1) mod2-lm(y~a+b+c+a:b) glmulti(mod2,

[R] glmulti: excluding intractions between variables

2010-08-03 Thread Marino Taussig De Bodonia, Agnese
Hello, I'm using the glmulti package to run models of all the possible combinations of my variables. However, I am only interested in a few interactions between them. I have tried the equivalent of: 1) mod1-lm(y~a+b+c+a:b) glmulti(mod1, level=1) 2)mod2-lm(y~a+b+c+a:b)

[R] PCA and Regression

2010-07-06 Thread Marino Taussig De Bodonia, Agnese
Hello, I am currently analyzing responses to questionnaires about general attitudes. I have performed a PCA on my data, and have retained two Principal Components. Now I would like to use the scores of both the principal comonents in a multiple regression. I would like to know if it makes