principle components

  1. G

    Do I need to transform my data before PCA?

    Hi, I have 18 variables (soil biogeochemical properties) that I want to put through a PCA. Some variables have large units (e.g. %) and some small (e.g. mg C/L). Should I transform the larger units before running them through PCA? Some of the variables also have non-normal data; should I also...
  2. M

    Choosing factors for principle components analysis

    Hello, I am running a PCA on a dataset that includes 43 water wells, each with up to five descriptive factors associated with it (temp, distance to significant location, depth, number of taxa, volume of flow). I am using XLSTAT to perform the analysis. Running the PCA with the whole...
  3. B

    [Primer-E] PCA - no option for varimax rotation?

    Hi, I am trying to figure out how to run a PCA on some behavioural data in Primer-E. Just a little confused as in the manual there is no reference to choosing a type of rotation, which I understand is usually Varimax. Am I missing something, or does Primer simply not use rotation...