----- Forwarded message from Dean Adams <[email protected]> ----- Date: Fri, 15 Mar 2013 10:24:56 -0400 From: Dean Adams <[email protected]> Reply-To: Dean Adams <[email protected]> Subject: Re: Geomorph error To: [email protected]
Murat, A perfectly symmetrical reference shape could cause this problem. With perfect symmetry, the positions of landmarks on one side of the mid-line describe the positions of their corresponding landmarks on the other side. The resulting L-matrix for that reference contains redundancies, which means it will be singular, and cannot be inverted with standard approaches. Dean -- Dr. Dean C. Adams Professor Department of Ecology, Evolution, and Organismal Biology Department of Statistics Iowa State University Ames, Iowa 50011 www.public.iastate.edu/~dcadams/ phone: 515-294-3834 On 3/15/2013 1:29 AM, [email protected] wrote: > ----- Forwarded message from Murat Maga <[email protected]> ----- > > Date: Thu, 14 Mar 2013 05:00:15 -0400 > From: Murat Maga <[email protected]> > Reply-To: Murat Maga <[email protected]> > Subject: Geomorph error > To: [email protected] > > Hi, > > I am getting: > > plotRefToTarget(AA,AB) > Error in solve.default(L) : > system is computationally singular: reciprocal condition number = 1.11926e-16 > > error when I try to use "TPS" method. These two shapes are in 3D. They are > pretty similar to each other, but of course not identical. Other methods > "vector" and "point" work fine for the same two. > > Murat > > ----- End forwarded message ----- > ----- End forwarded message -----
