Hi, I was going to post the same question regarding problem number 1 last week. I was working with a small data set (N = 5 for each of three species within one species group of a genus) with 17 landmarks on fly wings. Two of the species are sibling species, so very similar. I worked around the problem by either reducing the number of landmarks to 5 (deleting "noisy" and very similar landmarks) or by increasing the sample size.
I am curious about what is causing the problem, too. Ed ************************************* Edward A. Lisowski, Ph.D. WA Department of Agriculture Plant Protection, Pest Division [EMAIL PROTECTED] 509-225-2603 (ph) 509-454-7858 (fax) -----Original Message----- From: morphmet [mailto:[EMAIL PROTECTED] Sent: Tuesday, February 13, 2007 11:36 AM To: morphmet Subject: Advice on IMP Hi everybody! I am using geometric morphometrics in a study on mandibles of mice. I have encountered problems using programs in the IMP series, and I would be very grateful if somebody more experienced with these could give me a hint on what to do here: 1)I load an output file from CoordGen and a GroupList file into CVAGen. The program displays the landmarks but does not finish the analysis, instead posting an error message: “The within-group sum of squares and cross products matrix is singular”. I have inspected both input files several times; I cannot find any error; they do also perform well in PCAGen. What does the message tell me about my data? -- Replies will be sent to the list. For more information visit http://www.morphometrics.org
