similar to: What are the return values of aov?

Hi, I run the following commands. 'A' has 3 levels and 'B' has 4 levels. Should there be totally 3+4 = 7 coefficients (A1, A2, A3, B1, B2, B3, B4)? > a=3 > b=4 > n=1000 > A = rep(sapply(1:a,function(x){rep(x,n)}),b) > B = as.vector(sapply(sapply(1:b, function(x){rep(x,n)}), function(x){rep(x,a)})) > Y = A + B + rnorm(a*b*n) > > fr =

I read somewhere that t.test is equivalent to a hypothesis testing for one way ANOVA. But I'm wondering how they are equivalent. In the following code, the p-value by t.test() is not the same from the value in the last command. Could somebody let me know where I am wrong? > set.seed(0) > N1=10 > N2=10 > x=rnorm(N1) > y=rnorm(N2) > t.test(x,y) Welch Two Sample t-test data:

I have the following code. I'm wondering why summary() doesn't show F value and Pr? Rscript multi_factor.R > a=3 > b=4 > c=5 > d=6 > e=7 > > A=1:a > B=1:b > C=1:c > D=1:d > E=1:e > > X=matrix(nr=a*b*c*d*e,nc=5) > colnames(X)=LETTERS[1:5] > > for(i_a in 1:a-1) { + for(i_b in 1:b-1) { + for(i_c in 1:c-1) { + for(i_d in 1:d-1) { +

Hi, I don't understand what the meaning of the following lines returned by model.matrix(). Can somebody help me understand it? What can they be used for? attr(,"assign") [1] 0 1 2 2 attr(,"contrasts") attr(,"contrasts")$A [1] "contr.treatment" attr(,"contrasts")$B [1] "contr.treatment" Regards, Peng > a=2 > b=3 > n=4

Hello R List: My problem is with a nested anova. I have read the r-help and it has answered some of my questions but i still need some help on this one. I have also posted for help on this data set before, so i apologize in advance for any repetition. My design is as follows: response: Quadrat Counts (individuals per quadrat) Explanatory: Region (3 regions) Locations (4

I think there are two bugs in aov() that shows up when the right hand side of `formula' contains both `-1' and an Error() term, e.g., aov(y ~ a + b - 1 + Error(c), ...). Without `-1' or `Error()' there is no problem. I've included and example, and the source of aov() with suggested fixes below. The first bug (labeled BUG 1 below) creates an extra, empty stratum inside

I believe you are right, but can you please explain why anyone would want to fit this model? It differs only in the coding from aov(y ~ a + b + Error(c), data=test.df) and merely lumps together the top two strata. There is a much simpler fix: in the line if(intercept) nmstrata <- c("(Intercept)", nmstrata) remove the condition (and drop the empty stratum later if you

Hi all, I am experimenting the function "manova" in R. I tried it on a few data sets, but I did not understand the result: I used "summary(manova_result)" and "summary(manova_result, test='Wilks')" and they gave a bunch of numbers... But I need the Sum-of-Squares of BETWEEN and WITHIN matrices... How do I read off from the R's manova results? Any

Dear R-Helpers, I suspect I'm about to ask a FAQ, but I haven't been able to find an answer in the FAQ, AItR or an R Site Search. When I look at the methods of summary (below) it says, "Non-visible functions are asterisked". I looked at the help file for summary.princomp, which did not comment on it being non-visible. I ran its help file example, which printed visible output. I

Hi, I want to do ANOVA for nested designs like following. I don't understand why the matrix (t(X) %*% X) is singular. Can somebody help me understand it? Regards, Peng > a=2 > b=3 > n=4 > A = as.vector(sapply(1:a,function(x){rep(x,b*n)})) > B = as.vector(sapply(1:(a*b), function(x){rep(x,n)})) > cbind(A,B) A B [1,] 1 1 [2,] 1 1 [3,] 1 1 [4,] 1 1 [5,] 1 2 [6,] 1 2 [7,]

I have the R code at the end. The last command gives me "1 observation deleted due to missingness". I don't understand what this error message. Could somebody help me understand it and how to fix the problem? > summary(afit) Df Sum Sq Mean Sq F value Pr(>F) A 2 0.328 0.16382 0.1899 0.82727 B 3 2.882 0.96057 1.1136 0.34644 C

Hi, I am looking for a complete description of the syntax of the formula that shall be specified in, for example, aov. But I can't find a complete description. Can somebody point to me if there is such a resource? Regards, Peng

I'm trying to write a function to automate doing a variance analysis, part of which involves doing some further calculations. The method I've been using isn't very robust, if variable names change then it stops working. For this dummy data > dput(assayvar,"") structure(list(Run = structure(c(1L, 1L, 1L, 2L, 2L, 2L, 3L, 3L, 3L, 4L, 4L, 4L), .rk.invalid.fields =

I am using rw0641 with Windows 98. In the help for aov it states that the formula can sepecify multiple responses for a "maov". The help doesn't give an example, Venables and Ripley 1997:381 doesn't either. It isn't mentioned in the scripts nor in the section R Complements nor in Rnotes. I tried aov(c(y1,y2,y3)~x) which seemed reasonable to me but doesn't work. How

Hi all, I search the archive for finding a simple solution for using TukeyHSD with a multistratum aov result (a repeated emasure anova). The Question have been asked but I've found no clear answer. res<-aov(y~Fa*Fb+Error(Subject/(Fa*Fb)) ) I think that the problem is that res is an aovlist object instead of the "aov" object required by TukeyHSD. Is there an easy solution to

It doesn't print anything: the summary.aov (or summary.aovlist) print method does. ?summary.aov tells you the structure of the objects they return. On Tue, 15 Feb 2005, RenE J.V. Bertin wrote: > I'd like to annotate a plot with the output of summary(aov(model)), > ideally just with the significant effects. I don't find a means to > redirect what that command prints into

Dear all, Type III SS time again. This case trying to reproduce some SPSS (type III) data in R for a repeated measures anova with a betwSS factor included. As I understand this list etc, if I want type III then I can do library(car) Anova(lm.obj, type="III") But for the repeated measures anova, I need to include an Error-term in the aov() call (Psychology-guide from Jonathan Baron)

Is there an easy way of converting an aov.summary into a matrix in which the rows are the factor names and the columns are Df, Sum Sq, Mean Sq, F value and Pr. For example, convert Df Sum Sq Mean Sq F value Pr(>F) block 5 343.29 68.66 4.4467 0.015939 * N 1 189.28 189.28 12.2587 0.004372 ** P 1 8.40 8.40 0.5441 0.474904 K

Hello, I am trying to print out ANOVA summaries --- as returned by summary (aov(...))--- in tab-delimited format, either to a file or to the console, but so far I haven't been able to figure out a solution. My particular ANOVA has repeated measures, so it is an instance of class aovlist. Can anyone offer any suggestions? I am relatively new to R, so please forgive me if I am missing

R developers, I have a first attempt to make an aov function. Eventually I want to build in Error() structure, but first I am trying to get this presentable for balanced data with only a single stratum, just using residual error. I am following R. M. Heiberger's Computation for the Analysis of Designed Experiments, Wiley (1989) I a using a wrapper (aov.bal) to call the