To get an intuitive appreciation of the uniform component you could use the tpsRelw program. Load some data and then press the 'consensus' and 'partial warps' buttons. Then click on the button to display the partial warps. The initial display in that window is just for the uniform component. Click on the camera icon and then move the red circle around and you will see how different values of the uniform component yield different shapes.
Note that in the options menu of the main window you can select whether to use the Bookstein (1996) method or one of the two newer methods described in Rohlf and Bookstein (2003). You must select the method before you compute the partial warps. ----------------------- F. James Rohlf State University of New York, Stony Brook, NY 11794-5245 www: http://life.bio.sunysb.edu/ee/rohlf > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of [EMAIL PROTECTED] > Sent: Friday, July 09, 2004 8:57 AM > To: [EMAIL PROTECTED] > Subject: uniform components > > Dear Morphometricians > Would you please help me in understanding the meaning > of uniform components? I know these describe how much > a specimen is stretched on X or Y axis. > I also know we extract these components after > superimposition and it means size is eliminated before > computing uniform components. > What would be the interpretation, if a specimen has > bigger values for both U1 and U2? It seems affine > stretching in both horizontal and vertical directions > should present bigger size and affine contraction in > these tow directions should present smaller size. So > if the size has been eliminated before, what would be > the interpretation? I mean whats the difference > between a specimen which has low values for U1 and U2 > and a specimen which has high values for both. > Any comments would be appreciated in advance > Sincerely yours > Roohollah > > == > Replies will be sent to list. > For more information see http://life.bio.sunysb.edu/morph/morphmet.html. == Replies will be sent to list. For more information see http://life.bio.sunysb.edu/morph/morphmet.html.
