search for: scheff

Hi R-people, I am wanting to run Factorial ANOVA followed by Scheffe tests on some spatial subjective data. I'm comparing X-Y independent coordinates against x-y dependent coordinates. There are only four independent spatial coordinates that form a square. I am wondering whether I am doing the right thing, because there doesn't seem to be a simple way of d...

...looking for help in gaining understanding of this powerful tool. I am becoming more proficient with using basic functions to conduct basic statistics. I am now looking to learn how to write code. After a few small worthless functions I decided to try to create a function that was of real use, a Scheffe test for doing post hoc comparisons. I am not aware of any functions written for this though there may be some. I wrote the function and have run each line of the function through R. It seems to work (though can use some improvements later on by splicing code from aov or anova functions to elim...

Dear all, Please help me with the R code which compute SCHEFFE TEST Thanking you in advance Kind regards Mangalani Peter Makananisa Statistical Analyst South African Revenue Service (SARS) Segmentation and Research : Data Modelling Tel: +2712 422 7357 Cell: +2782 456 4669 Fax:+2712 422 6579 Please Note: This email and its contents ar...

Hello everyone I'm trying to use Scheffe's complete cubic model (mixture design). In the bibliographies, they indicate that the term is of the type: A * B * (A-B). But I see that trying to adjust the three cubic terms results in singularities. I know this implies not having the inverse matrix: solve (t (X)% *% X) does not exist....

Mangalani Peter Makananisa would like to recall the message, "Scheffe test". Please Note: This email and its contents are subject to our email legal notice which can be viewed at http://www.sars.gov.za/Email_Disclaimer.pdf [[alternative HTML version deleted]]

Dear List, are there post-hoc tests like Scheffe, LSD, etc. available after ANOVA test is performed with significant F-statistic? I have tried help.search("Scheffe"), but "No documentation found" (and I have most of packages installed). Probably there are such tests in R, and I am just searching badly... My second question i...

...ume that the p values given by the summary are not corrected for multiple testing. Thus, I might correct them with p.adjust(). But since the contrasts are not independent, I'm not sure if the adjustment methods would work here. On the other hand, I've come across a procedure called "Scheffe's multiple comparisons" (or S test), which is said to be appropriate for multiple contrasts like these. Before I try to implement it: Has anybody already done that, or are there good reasons not to use it? BTW, I tried to extract the SEs of the contrasts by se.contrast(), but it woul...

...ave a completely randomized design, and I want to have the contrast \mu_1 - 0.5 \mu_2 - 0.5 \mu_2 How do I set that up, please? I used the C command, and ran aov, but the results were identical to those with no contrasts. Also, is there a command for Dunne'ts multiple range test? How about Scheffe's simultaneous intervals? Thank you so much for your help, in advance! Sincerely, Erin Hodgess Associate Professor Department of Computer and Mathematical Sciences University of Houston - Downtown 1 Main Street Houston, TX 77002 mailto: hodgess at uhddx01.dt.uh.edu -.-.-.-.-.-.-.-.-.-.-.-.-...

...n R. Could anyone point us to any information concerning - univariate approach to repeated measures anova - multivariate approach to repeated measures anova - mixed designs - Greenhouse-Geisser epsilon correction - Newman-Keuls contrasts - LSR contrasts - Tukey contrasts - Scheffe contrasts Any help or comment appreciated. Since we are not in the mailing list yet, please cc your reply to volker.franz at tuebingen.mpg.de. Thanks, Volker -- ___________________________________________________________ Volker Franz Max-Planck-Institut fuer biologische Kybernetik...

...17 1 0 0 0 0 1 13 0 1 0 1 0 0 9 0 1 0 0 1 0 10 0 1 0 0 0 1 11 0 0 1 1 0 0 17 0 0 1 0 1 0 17 0 0 1 0 0 1 16 ############################### # CODE ############################### x = read.table(file("clipboard"),h=T) ## NOT a Scheff?? Model: x.lm <- lm( y ~ (z1+z2+z3):(x1+x2+x3), data=x) summary(x.lm) anova(x.lm) ## Scheff?? Model: <- IS CORRECT the analysis below? x.lm <- lm( y ~ -1 + (z1+z2+z3):(x1+x2+x3), data=x) summary(x.lm) x.aov <- aov( y ~ (z1+z2+z3):(x1+x2+x3), data=x) summary(x.aov)

Buenas tardes   Estoy intentando representar graficamente la elipse de confianza de dos pendiente en un modelo sin intercepto La formula que introduzo esplot(ellipse(recta,c(1,1)),type="l"), pero elipse me sale una recta   Gracias [[alternative HTML version deleted]]

Hello ALL: I am looking for multiple comparison tests for ANOVA models. Does R have any of these? Fisher least significant difference test. Tukey henestly significant difference test. Newman - Keul test. Dunnett's test Scheffe test. Thank you, ANDREW -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !)...

Does anyone know of some methods already programmed up ( ie freeware : ) ) in R for the post hoc methods in anova. Particularly Scheffe's method or Tukey's? Anna

Hello, I am interested in parametric multi comparison tests such as Dunnett, Duncan, Tukey, Newman-Keuls, Bonferonni, Scheffe, and non-parametric tests such as Kruskal-Wallis, and Mann-Whitney U. Are there packages that include most of these tests in each category? Many packages exist for an individual test but their outputs vary in great detail (test statistics, p-values, etc.) formats. It is desirable to have one tha...

...eading Dr. Harrell's excellent "Regression Modeling Strategies" book and trying out the exercises. I understand that contrast( ) is used to obtain contrasts between two variables for given levels of other nuisance variables; is there a way to use contrast( ) to obtain, for example, Scheffe confidence intervals / hypothesis tests for many post hoc contrasts at once? Any help would be much appreciated, Greg

Greetings all, I've done some ANOVAs and have found significant effects across my groups, so now I have to do some post-hoc tests to ascertain which of the groups is driving the significant effect. Usually one would do something like a Newman-Keuls or Scheffe test to get at this but based on googling and browsing through the r-help archives R doesn't support these and they seem to be badly received by the R community generally (for reasons related to alpha not being properly controlled, if I understand correctly). I found the TukeyHSD function but...

...y). Is a function available that extracts multiple comparison of means from objects produced by "aov()" ? Sorry if the term is not correct, I translated from german word by word ("Multiple Mittelwertvergeiche"). What I mean are procedures like the Student-Newman-Keuls test or Scheffe test, that allow to test selected pairs of factor combinations after applying an ANOVA to a set of data. I'm somewhat surprised that this seems not to be a topic of discussion among R-users since great emphasis is put on these procedures in most (german) textbooks on applied (bio)statistics....

This is maybe not directly an R problem but I have used R to try to solve it so I think somebody may be able to help. I have a mixture model with three components and a quadratic Scheffe polynomial p1x1+p2x2+p3x3+p12x1x2+p13x1x3+p23x2x3 fitted to the response. Now I'd like to compute the mixture corresponding the maximum response. Model for Y1 has the parameters p1=124.02 p2=60.973 p3=41.479 p12=106.824 p13=140.422 p23=81.012 Solving a system of linear equations (solve(A,b))...

...Statistics pg 296, and Linear Models with R pg. 39 (Although in this instance the intervals are called 95% "pointwise" confidence bands versus simply 95% confidence bands.) To make a confidence/prediction band, one should construct simultaneous confidence/prediction intervals with say a Scheffe approach as mentioned in the S-PLUS Guide to statistics pg 274. If these connected intervals were called pointwise confidence/prediction intervals with the understanding that have no particular probability interpretation, then they are useful in understanding where the line should fall. However,...

...e comparisons I was used to do in SAS. With the SAS/STAT, I generally used the MEANS (for comparison of arithmetic means) and the LSMEANS (for adjusted means) statements of the GLM procedure (I think it is equivalent to lm in R). They provided a lot of tests: LSD, Duncan, Tukey-Kramer, Bonferroni, Scheff??, SNK, etc. However, in R I have only discovered Tukey-HSD. I have searched for information about this, but I was not successful. I wonder if anybody knows where I could learn about this. I would like to use these tests in R, and also obtain the adjusted means like these produced by the LSMEANS s...