search for: treatement

Hello, I'm begining with R and I'm very interested to treat satellite images with it. I want to ask you: a) Is it possible to read binary files with R? b) How could I view images (in a matrix array format) with R? thank you very much Carlos -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read

Hi, I want to do a meta-analysis with count data for treatement/control cases. Mi problem is that I need to use zero values (an informative zero value) for the mean and standard deviation for one of the treatement, but R has a problem: "Studies with zero values for sd.e or sd.c get no weight in meta-analysis". I can agroup the case by Family (byvar=Fa...

Hi! I want to do a meta-analysis with count data for treatement/control cases. Mi problem is that I need to use zero values (an informative value) for the mean and standard deviation for one of the treatement, but R has a problem: "Studies with zero values for sd.e or sd.c get no weight in meta-analysis". I can agroup the case by Family (byvar=Family)...

dear list, i am using a multifactorial design with two treatments (factor A: drugs, three levels; factor B: theraphy, two levels) and a time factor (three levels, different timepoint). hypothetically, i measured the same subjects for all treatements and timepoints, so its a repeated measurement design. now i ran an anova in R and also some Tukey post-hoc tests using glht. but what i am actually interested in is to perform conditional contrasts, f.i. A1 for the 1st timepoint vs. A1 for the 2nd time (to put it in words: an evaluation of whether...

...ve 20 subjects in two groups of treatment (8 an 12 subjects). Biological measure have been recorded at different time, from t0 (before the treatment) to t7 (3 days after). The time elapsed between each measure is not constant. What is the most appropriate test to show a difference between the 2 treatements? I thought that an anova for repeated measure could do the trick, but I didn't really find how to do it with R. I sorry for being OT but I didn't really know where to ask this question. If you could redirect me on a appropriate forum or mailing list to have that sort of help, I would...

Hello, I have a problem with creating an identity matrix for glmnet by using the contrasts function. I have a factor with 4 levels. When I create dummy variables I think there should be n-1 variables (in this case 3) - so that the contrasts would be against the baseline level. This is also what is written in the help file for 'contrasts'. The problem is that the function

...ght way to do it. My experiment consists of manipulating FRUITS and VEGETATION to two levels each(intact or removed) on 12 experimental plots. This leaves me with 4 treatment combinations Fruit intact Vegetation removed Fruit int. Veget int. Fruit rem. Veget rem. Fruit rem. Veget. intac those treatements are distributed accross 3 blocks. Plots were repeated surveyed for mice using 16 PLATES that recorded mice TRACK prints on each block. I am trying to create a grouped data that incorporates the the fixed effects of FRUIT VEGETATION TIME and random repeated measures for PLATE and random effects f...

Hi, I have a problem with understanding what the function cast() from the package reshape is doing. In the example below I have a 2x2x2 array which I first melt and then cast to get the averages over the field 'strain' for every combination of the fields 'treatement' and 'gene': ------ > mdat <- melt(array(rnorm(8), dim=c(2,2,2), dimnames=list(strain=c("s1", "s2"), treatment=c("t1", "t2"), gene=c("g1", "g2"))))...

Dear all, In R-devel I have noticed the new approach for the "ts" class in the package "methods". the "structure" behaviour of "ts" is not always kept when one uses "ts" objects and objects of classes which extend the virtual class "structure". As a short example: ## this works fine setClass("foo", representation(header =

...t;class", vt.difft = vt.for, threshold = quantile(vt.for$difft, seq(.5,.8,.1)), maxdepth = 2) # Print results vt.sbgrps <- vt.subgroups(vt.trees) knitr::kable(vt.sbgrps) ``` Subgroup Subgroup size Treatement event rate Control event rate Treatment sample size Control sample size RR (resub) RR (snd) ------ ---------------------------- -------------- ---------------------- ------------------- ---------------------- -------------------- ----------- --------- tree1 PRAPACHE>=26.5...

...t;class", vt.difft = vt.for, threshold = quantile(vt.for$difft, seq(.5,.8,.1)), maxdepth = 2) # Print results vt.sbgrps <- vt.subgroups(vt.trees) knitr::kable(vt.sbgrps) ``` Subgroup Subgroup size Treatement event rate Control event rate Treatment sample size Control sample size RR (resub) RR (snd) ------ ---------------------------- -------------- ---------------------- ------------------- ---------------------- -------------------- ----------- --------- tree1 PRAPACHE>=26.5...

...er people are orphaned. We have a cross-over design, where patient are treated two weeks with placebo, two weeks with a drug ("verum"), and a washout phase in between. For each phase, there is ONE number (let's call it "glucose level") describing the treatment effect. Blind treatement sequence is Seq=1 for placebo/verum, Seq=2 for verum/placebo. In Pinheiro/Bates, cross-over trials are mentioned on page 107, but the parameter "Side" in the example is not exactly what we have. We used the scheme below to analyze the data (there is a small effect of imperfect washout in...

...s marginally significant (p=0.04). I would like to know where that significance came from, so I did ALL pairwise t tests (treat1 vs. control, treat2 vs. control, treat1 vs. treat2) at each of the time point. There are 2 ways I can do these t tests, using the MSE from the ANOVA (the MSE used for the treatement effect in the ANOVA, i.e. the treatment by time interaction) as the t test error, or simply ran ordinary t tests using only the data of the treatment levels in comparison. What I found is that using the first approach, I couldn't find any pairwise comparison statistically significant which I th...

On 2/28/07, Ivo Emanuel Gon?alves <justivo@gmail.com> wrote: > On 2/28/07, Ralph Giles <giles@xiph.org> wrote: > > Well, there are todo pages at wiki.xiph.org, but I meant more in the > > community folklore sense. My point is a roadmap doesn't help much unless > > there are people committed to making things happen. That's been the > > problem with a

On 2/28/07, Ivo Emanuel Gon?alves <justivo@gmail.com> wrote: > On 2/28/07, Ralph Giles <giles@xiph.org> wrote: > > Well, there are todo pages at wiki.xiph.org, but I meant more in the > > community folklore sense. My point is a roadmap doesn't help much unless > > there are people committed to making things happen. That's been the > > problem with a

I am appealing to the general collective wisdom of this list in respect of a statistics (rather than R) question. This question comes to me from a friend who is a veterinary oncologist. In a study that she is writing up there were 73 cats who were treated with a drug called piroxicam. None of the cats were observed to be subject to vomiting prior to treatment; 12 of the cats were subject to