-------- Original Message -------- Subject: Re: Shaping of throwed pottery Date: Sun, 6 Jan 2008 10:49:02 -0800 (PST) From: Dennis E. Slice <[EMAIL PROTECTED]> To: [email protected] References: <[EMAIL PROTECTED]>
This is a very interesting problem, and one I have had in the back of my mind for some time. I am not familiar with any work in this area from the biological morphometrics community. Since these are thrown on a wheel, I assume the final and intermediate producs are symmetrical. You don't have the issue of developmental or evolutionary homology to address, so you really have just a 2D problem with all the information contained in the profile. You could densely sample the 2D profile starting with the lump of clay with evenly spaced points and follow their change through to the final product. Actually, because of symmetry, you only have to follow half of that profile. Perhaps starting from the wheel-clay edge up to the middle of the lump, then following that middle as it moves out to become the edge. [you would also need to account for the displacement of the edge away from the center, so maybe you would need one more point at the center of the bottom of the pot - still 2D. Note added in posting by the moderator (also dslice)] At different time points, you would have a trajectory through shape (or size/shape) space of the evolution of the shape/form. There would probably not be a temporal homology that would allow you to match time/shape points (as in "toe-off" in gait studies). So, you would have to parameterize the trajectory with some general function. I used EFA in a poster presented for gait analysis at the AAPA one year, but you don't have cyclical shape change. Therefore, you would have to do something else. Maybe resampling using parametric splines or (less likely) polynomial regression. I know of no ready-made software to do any of this, so it would pose a programming/math/statistical challenge, but one worth pursuing, I think. Then again, mathematicians (i.e., topologists) may have already worked all of this out. I would very much like to hear from someone knowledgeable of that field. Best, dslice morphmet wrote: > -------- Original Message -------- > Subject: Shaping of throwed pottery > Date: Sun, 06 Jan 2008 18:05:02 +0100 > From: Enora GANDON <[EMAIL PROTECTED]> > To: morphmet <[EMAIL PROTECTED]> > > > Dear Moderator, > > I begin a thesis, which subject is the shaping of throwed pottery. > I come from ethnology and human movement sciences. > The aim of the study is to compare patterns of making pottery in a > wheel in different countries. > > So, I look for descriptors of the evolutive shape of the pottery. > These descriptors must be consistent with the execution of the > movement, that is take in account the stability of the 'clay structure'. > > If some people have some tracks... > > Thanks. > -- Dennis E. Slice Department of Anthropology University of Vienna ======================================================== -- Replies will be sent to the list. For more information visit http://www.morphometrics.org
