I recently upgraded to the new version of Demeter (0.9.20) for Mac and am trying to run principal components analysis on my spectra. When I click on "Principle components analysis" from the main menu, the window shows the following message: 

"PCA is not enabled on this computer.

The most likely reason is that the perl modules PDL and/or PDL::Stats are not available."

Perhaps the solution here is simple, but I am not familiar with perl modules and do not understand the source of the issue. I could not find information about this problem in the Mail Archive, though I may have missed something. Do I need to download the PDL perl modules separately from the Demeter installation? Could there be files that are not located in the proper directory? Or perhaps PCA is simply not available for Macs? 

Please let me know if further information would help in solving this problem.

Thank you!

Ellen