I am running normalmixEM: mixmdlscaled <- normalmixEM(data$FCWg) summary(mixmdlscaled) plot(mixmdlscaled,which=2) If I run the program multiple times, I get widely different results: > mixmdlscaled <- normalmixEM(data$FCWg) number of iterations= 41 > summary(mixmdlscaled) summary of normalmixEM object: comp 1 comp 2 lambda 0.0818928 0.918107 mu 0.6575938 0.740870 sigma 0.0070562 0.178410 loglik at estimate: 56.87445 > plot(mixmdlscaled,which=2) > mixmdlscaled <- normalmixEM(data$FCWg) number of iterations= 357 > summary(mixmdlscaled) summary of normalmixEM object: comp 1 comp 2 lambda 0.959912 0.0400879 mu 0.722022 1.0220719 sigma 0.165454 0.0131391 loglik at estimate: 53.66051 > plot(mixmdlscaled,which=2)
I understand that when run without specifying various parameters (e.g. mu, or sigma) values are chosen randomly from a normal distribution with center(s) determined from binning the data. Despite this, would not one expect the results to be similar? If one is not to expect similar results, how can I get a solution in which I can have confidence? Should I run the program multiple times and take the average of the results? Should I look for the solution with the best log likelihood? Thank you, John John David Sorkin M.D., Ph.D. Professor of Medicine Chief, Biostatistics and Informatics University of Maryland School of Medicine Division of Gerontology and Geriatric Medicine Baltimore VA Medical Center 10 North Greene Street GRECC (BT/18/GR) Baltimore, MD 21201-1524 (Phone) 410-605-7119 (Fax) 410-605-7913 (Please call phone number above prior to faxing) Confidentiality Statement: This email message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply email and destroy all copies of the original message. ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.