Re: Asreml_R help: Is the model wrong?

From: Butler, David <David.Butler_at_DEEDI.QLD.GOV.AU>
Date: Fri, 4 Sep 2009 01:35:26 +1000

Dear Li, There was a (relatively) recent internal upgrade to asreml that broke the conditional F-tests and approximate stratum variance components of wald(). This has been corrected so all you may need is a later version than the one you have. Dave. -----Original Message----- From: ASReml users discussion group on behalf of yutao Sent: Thu 03-Sep-09 1:27 PM To: ASREML-L@DPI.NSW.GOV.AU Subject: Asreml_R help: Is the model wrong? Dear Brian/Arthur, I have a dataset (ecoli.txt) which contains the following information. ? 3 trials (trial1, trial2 and trial3) ? 2 treatments (trt1 vs trt2) ? Different sampling dates(sdate) were recorded for each treatment in each trial trial1: 7, 14, 20, 34, 56, 69, 83, 112, 154, 181, 205 trial2: 14, 27, 48, 69, 97, 125, 153, 183 trial3: 14, 27, 55, 76, 97, 133, 153, 174 ? Within each trial for each sampling date, logcount of ecoli were measured from sampling 3 different plates of 2 or 3 chambers of 3 blocks (A, B, C). trial1: 3 chambers /block trials 2 and 3: 2 chambers/block. The aim of the analysis is to examine the difference between two treatments in each trial and across trials, and predict the relationship between sampling date (sdate) and logcount for each treatment. I have used ASReml_R to fit the following model: asreml(logcount~trial+trial/treatment+trial/(sdate+sd2)+trial/treatment:(sdate+sd2),data=ecoli,random=~(trial/sdate):block/chamber/plate) The term sd2 is a quadratic of covariate sdate. The program gives the results, but it does not give a denominator df when I ask for conditional wald tests. Is my model wrong? The ASreml_R code: rm(list=ls()) ecoli=read.table("C:\\Documents and Settings\\li042\\Desktop\\ecoli.txt",sep="\t",header=T) library(asreml) ecoli$chamber <- as.factor(ecoli$chamber) ecoli$plate <- as.factor(ecoli$plate) ecoli$sd2<-ecoli$sdate^2 ecoli_m2.asr <- asreml(logcount~trial+trial/treatment+trial/(sdate+sd2)+trial/(treatment:(sdate+sd2)),data=ecoli,random=~(trial/sdate):block/chamber/plate) wald.asreml(ecoli_m2.asr, denDF = "default", ssType = "conditional")$Wald The data file is attached. Thanks in advance. Yutao Li -------------------- m2f -------------------- Sent using Mail2Forum (http://www.mail2forum.com). Read this topic online here: http://www.vsni.co.uk/forum/viewtopic.php?p=802#802 -------------------- m2f -------------------- Attachments: http://www.vsni.co.uk/forum/files/ecoli_633.txt This message is intended for the addressee named and may contain confidential information. If you are not the intended recipient, please delete it and notify the sender. Views expressed in this message are those of the individual sender, and are not necessarily the views of their organisation. ********************************DISCLAIMER**************************** The information contained in the above e-mail message or messages (which includes any attachments) is confidential and may be legally privileged. It is intended only for the use of the person or entity to which it is addressed. If you are not the addressee any form of disclosure, copying, modification, distribution or any action taken or omitted in reliance on the information is unauthorised. Opinions contained in the message(s) do not necessarily reflect the opinions of the Queensland Government and its authorities. If you received this communication in error, please notify the sender immediately and delete it from your computer system network.
Received on Sat Sep 04 2009 - 01:35:26 EST

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