Ken, This error message has nothing to do with the number of specimens in the data set (and I do not believe there is a maximum # of specimens for this operation). It means that the x,y coordinates the routine was trying to estimate for the first specimen did not become stable after the pre-set # iterations.
Remember what this approach does. It takes a set of distances, estimates the x,y (or x,y,z) landmarks from them, and compares the original distances to the distances between estimated landmarks. Then it moves the landmarks around based on one of several algorithms, re-estimates the distances, and compares these to the observed. This procedure is iterated until the differences between the observed and estimated distances does not improve, or until the limit of iterations is reached. My guess is that for your data set, you reached the limit of maximum iterations before things 'settled down' (i.e. before the estimated landmark coordinates converged). If this is the case, the solution is to increase the number of iterations. You can increase this in the 'Max Iterations' box. However, you should also bear in mind that depending on how many landmarks you are attempting to estimate from these distances, there may not be an estimable solution (i.e., you may be trying to estimate too many landmarks from too few distances). For file formats, see Truss-2d.cfg for an example of a configuration file, and Truss-2d.mea for an example of the distance measurement file. Both are found in the Morpheus folder and should come with the standard installation of the program. I believe a landmark estimation file (if you have one) would be in any standard format for a landmark file (tps, nts, etc.). Check with Dennis on that one. Hope this helps somewhat. Dean At 04:55 AM 7/13/2006, you wrote: >Hello all, >I have linear distance measurements (n = 5) from approximately 2500 shrew mandibles. I am interested in converting these distances to landmarks using Morpheus. The truss configuration file and truss distance file have been created, but when I run File/Import/Truss Data with Morpheus, I get the message "Object 1 Failed to Converge". I have a few questions about this operation; 1) is there a limit to how many specimens can be input into the program at once, 2) what is the proper format for the >configuration and distance files, 3) can catalog ID labels be included with the distance file or should it be just the raw data and 4) what exactly will the import of the landmark estimation file into Morpheus look like? I apologize for asking such basic questions about this and would greatly appreciate any insight. I should have used landmark data to begin with! Thanks. best to all, >ken berger >university of idaho, department of biological sciences >[EMAIL PROTECTED] > > > >-- >Replies will be sent to the list. >For more information visit http://www.morphometrics.org Dean C. Adams Associate Professor Department of Ecology, Evolution, and Organismal Biology, and Department of Statistics 253 Bessey Hall Iowa State University Ames, IA 50011 tel: (515) 294-3834 fax: (515) 294-1337 web: http://www.public.iastate.edu/~dcadams -- Replies will be sent to the list. For more information visit http://www.morphometrics.org
