I have been attempting to apply the spectra collected via ROIs in one image to another image with MLC classification. The procedure that was recommended on this forum was to calculate stats with covariance from the ROI tool, save the results to an ENVI stats file, and then use the Spectral->Mapping Methods->Endmember Collection tool to import the saved spectra and apply them to a new file. This has worked fine for a Landsat TM image, however when I create a file which is the 6 TM bands stacked with a few vegetation indices and a topographic variable the procedure no longer works. Specifically, when I get to the final "apply" step in the endmember collection tool I get an error message that: "Problem: The selected algorithm requires that the collected endmember spectra all contain an associated covariance. ENVI is unable to continue because some of the endmembers collected do not have their covariance" I have repeated the process many times verifying that the "calculate covariance with stats" option is checked prior to saving the stats files. I have also exported the stats files to text instead and the covariance is listed there for all bands. Additionally, the full covariance matrix is displayed in the stats tool prior to saving as ENVI stats files. So, I'm positive that the covariance information is there, but it is somehow not being recognized by the endmember collection tool. Even more confusing is the fact that the described procedure works fine for a 6 band image. Any ideas?