morphmet
Tue, 09 Feb 2010 12:15:35 -0800
-------- Original Message -------- Subject: Relative warp question Date: Mon, 1 Feb 2010 09:29:50 -0500 From: Richards Paul <plx...@nottingham.ac.uk> To: <morphmet@morphometrics.org> Hi , I am applying relative warp analysis to a population of land snails, but I am new to all the theory and methods. I’m doing a preliminary analysis to see if shell colour (i.e. dark, intermediate, light) is associated with differences in shape. I have run the relative warp analysis using tpsrelw, but have a few queries about using the output and potential analysis. RW1 to 3 appear to describe the apparent shape variance I am interested in (i.e. high spired vs flat and aperture size). Do the relative warps correspond directly to the identical partial warps in the weight matrix (e.g. RW1 scores column corresponds to the first variable column in the weight matrix)? If so could I take the first variable in the weight matrix (assuming it corresponds to RW1) and perform a T test just for this variable between my dark and light colour groups? I have tried using a MANOVA approach, but because these samples weren’t collected specifically with this analysis in mind I am lacking enough samples in each of my colour groups to get sufficient power, but I think a T test on a per variable basis should be OK in the first instance. I would be most grateful for any advice, and apologise if I have overlooked something obvious! Thanks, Paul ---------------- Paul Richards School of Biology University of Nottingham University Park NG7 2RD +44 (0)115 8213128 plx...@nottingham.ac.uk This message has been checked for viruses but the contents of an attachment may still contain software viruses which could damage your computer system: you are advised to perform your own checks. Email communications with the University of Nottingham may be monitored as permitted by UK legislation. -- For now, new message AND replies should be sent to: morphmet_modera...@morphometrics.org /* Replies will be sent to the list. */ For more information visit http://www.morphometrics.org