Dear Michael F
What you say is of course true but Michael E (or possibly Simone) seems
to be using a function glht from an unnamed package. Since we do not
have the data or the offending output it is hard to be sure though.
Michael D
On 20/05/2016 13:49, Michael Friendly wrote:
Use car::Anova() for type II and type III sums of squares and F-tests.
The sequential type I tests computed by anova() are rarely sensible
On 5/20/2016 3:11 AM, michael.eisenr...@agroscope.admin.ch wrote:
Dear R-list members,
I compared my statistics with my supervisor yesterday. He is using
STATISTICA, I am using R. We both loaded the same data-file and did a
two-way ANOVA with treatment and trial as factors; treatment means
were then compared to the untreated control using Dunnett's test.
Surprisingly, we got different values, especially the F values
differed. In the following Dunnett's test, some treatments were
significant in R, but not in STATISTICA. We checked the basic settings
of the programs and found out, that STATISTICA is using
"sigma-restricted parametrization" and "type VI sum of squares" for
the calculations, but so far, I could not find any information about
the sum of squares type, which is applied in R. Is it possible, that
these settings are the reason for the different values we got? And how
can I change in R these settings?
Here the code I used:
bt_assay_devtime_Model <-
aov(developmenttime~treatment+run+treatment*run, data=bt_assay)
summary(bt_assay_devtime_Model)
postHocs_bt_assay_devtime <- glht(bt_assay_devtime_Model,
linfct=mcp(treatment="Dunnett"), base=1)
summary(postHocs_bt_assay_devtime)
confint(postHocs_bt_assay_devtime)
Thanks a lot for your help!
Simone
Eisenring Michael, Msc.
PhD Student
Federal Department of Economic Affairs, Education and Research
EAER
Institute of Sustainability Sciences ISS
Biosafety
Reckenholzstrasse 191, CH-8046 Z�rich
Tel. +41 44 37 77181
Fax +41 44 37 77201
michael.eisenr...@agroscope.admin.ch<mailto:michael.eisenr...@agroscope.admin.ch>
www.agroscope.ch<http://www.agroscope.ch/>
[[alternative HTML version deleted]]
______________________________________________
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.
--
Michael
http://www.dewey.myzen.co.uk/home.html
______________________________________________
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.
