1. M

    Contrast drop off from factor x in using predict in decision tree in R

    Hi, I have tried research about this error warning message for several days without any info, e.g. ": contrasts dropped from factor staffx.f" etc.. as I tried to use newly decision tree model with the predict function on test data within the rpaprt package. Here are the scripts that I...
  2. R

    Confused with Contrasts

    Hello, during the last days, I tried to understand the use of contrasts, but the more I read, the more I am confused. As far as I understand, a contrast represents a specific hypothesis regarding the relationship between means of K levels of a factor variable. This is done via...
  3. F

    assist in design matrix,contrast matrix using limma

    Hi all, I'd really appreciate if someone can explain to me whether I've taken the following steps correctly. I'm trying to find the difference in gene expression between (wt vs mutant) for illumina mouse data(MouseWG-6 v2.0 chip). I used a design and contrast matrix (although i'm not sure...