similar to: stratified Wilcoxon available?

Displaying 20 results from an estimated 4000 matches similar to: "stratified Wilcoxon available?"

2010 Sep 14
0
stratified Wilcoxon's rank sum test with the locally best weights
Hello, I have been informed that there is no R package for the stratified Wilcoxon's rank sum test (Van Elteren's test) with the locally best weights. I need to use the alternative test to a clinical endpoint where the distribution approximate normal distribution, and compare to the regular ANOVA. I have been directed to use SAS with PROC FREQ with the SCORES=modridit option and CMH2
2010 Dec 31
3
survexp - example produces error
Dear All, reposting, because I did not find a solution, maybe someone could check the example below. It's taken from the help page of survdiff. Executing it, gives the error "Error in floor(temp) : Non-numeric argument to mathematical function" best regards, Heinz library(survival) ## Example from help page of survdiff ## Expected survival for heart transplant patients based
2009 Mar 28
1
stratified variables in a cox regression
>Hello, I am hoping for assistance in regards to examining the contribution of stratified variables in a cox regression. A previous post by Terry Therneau noted that "That is the point of a strata; you are declaring a variable to NOT be proportional hazards, and thus there is no single "hazard ratio" that describes it". Given this purpose of stratification, in the
2009 Apr 25
3
Nomogram with stratified cph in Design package
Hello, I am using Dr. Harrell's design package to make a nomogram. I was able to make a beautiful one without stratifying, however, I will need to stratify to meet PH assumptions. This is where I go wrong, but I'm not sure where. Non-Stratified Nomogram:
2004 Nov 30
6
How to know if a bug was recognised
Hello! A problem with special characters seemed to me to be a bug. I sent a mail to R-windows at r-project.org concerning the problem (see below). How can I find out, if this is considered as a bug or an error of myself? Which part of FAQs or documentation did I miss to find the answer? thanks in advance Heinz T??chler -------------------- copy of abovementioned mail ---------- to: R-windows
2004 Sep 28
2
Validating a Cox model on an external set
Good morning, Sorry to trouble the list. I have a problem I hope to seek your advice on. Essentially, I am trying to 'validate' a multivariate Cox proportional hazards model built in a training set, by testing it on an external test set. I have performed a survfit using the Cox model to predict survival for the test set, and obtained individual predictions for survival time, with
2005 Feb 04
5
How to access results of survival analysis
Hello, it seems that the main results of survival analysis with package survival are shown only as side effects of the print method. If I compute e.g. a Kaplan-Meier estimate by > km.survdur<-survfit(s.survdur) then I can simply print the results by > km.survdur Call: survfit(formula = s.survdur) n events median 0.95LCL 0.95UCL 100.0 58.0 46.8 41.0 79.3 Is
2005 Apr 02
4
factor to numeric in data.frame
Dear All, Assume I have a data.frame that contains also factors and I would like to get another data.frame containing the factors as numeric vectors, to apply functions like sapply(..., median) on them. I read the warning concerning as.numeric or unclass, but in my case this makes sense, because the factor levels are properly ordered. I can do it, if I write for each single column
2005 Aug 10
5
how to write assignment form of function
Dear All, where can I find information about how to write an assigment form of a function? For curiosity I tried to write a different form of the levels()-function, since the original method for factor deletes all other attributes of a factor. Of course, the simple method would be to use instead of levels(x) <- newlevels, attr(x, 'levels') <- newlevels. I tried the following: ##
2006 May 24
3
How to make attributes persist after indexing?
Dear All! For descriptive purposes I would like to add attributes to objects. These attributes should be kept, even if by indexing only part of the object is used. I noted that some attributes like levels and class of a factor exist also after indexing, while others, like comment or label vanish. Is there a way to make an arbitrary attribute to be kept after indexing? This would be especially
2004 Nov 30
1
Attn Heinz Tuechler: Re: problem with special characters (ä,ö,ü)
[I tried to send this message privately, but the return address bounced.] I think this has been fixed in R-patched, but I doubt if the fix has been tested in Win98. Could you please download a copy from <http://cran.r-project.org/bin/windows/base/rpatched.html> and confirm that it has been fixed? Duncan Murdoch On Sat, 27 Nov 2004 23:31:23 +0100, Heinz Tuechler <tuechler at gmx.at>
2008 Dec 04
1
Comparing survival curves with "survdiff" "strata" help
ExpeRts, I'm trying to compare three survival curves using the function "survdiff" in the survival package. Following is my code and corresponding error message. > survdiff(Surv(st_months, status) ~ strata(BOR), data=mydata) Error in survdiff(Surv(st_months, status) ~ strata(BOR), data = mydata) : No groups to test When I check the "strata" of the variable. I get .
2001 Nov 01
1
Stratified study.
Hello, I am analyzing the results of a survey of the student body on the use of certain technologies. The student body was divided in strata according to two criteria, college and user class. The resulting 24 strata were sampled. Subjects filled out a survey with a number of questions, most of them of the yes-no variety. I created a data.frame with the results for the survey. One row for
2005 Mar 25
3
Stratified bootstrap question
Dear experts, I am asking for help with a question regarding to stratified bootstrap. My dataset is a longitudinal dataset (3 measurements per person at year 1, 4 and 7) composed of multiple clinic centers and multiple participants within each clinic. It has missing values. I want to do a bootstrap to find the standard errors and confidence intervals for my variance components. My model is a
2010 Jul 07
1
Appropriateness of survdiff {survival} for non-censored data
I read through Harrington and Fleming (1982) but it is beyond my statistical comprehension. I have survival data for insects that have a very finite expiration date. I'm trying to test for differences in survival distributions between different groups. I understand that the medical field is most often dealing with censored data and that survival analysis, at least in the package survival,
2012 Jul 12
1
permutation test on paired samples
Hi, I'm trying to run a permutation test on paired samples. First I tried the package "exactRankTests": require("exactRankTests") x <- c(1.83,0.50,1.62,2.48,1.68,1.88,1.55,3.06,1.30) y <- c(0.878,0.647,0.598,2.05,1.06,1.29,1.06,3.14,1.29) wilcox.test(x,y,paired = TRUE,alternative = "greater") perm.test(y,x,paired = TRUE,exact = TRUE,alternative =
2005 Sep 08
3
change in read.spss, package foreing?
Dear All, it seems to me that the function read.spss of package foreign changed its behaviour regarding factors. I noted that in version 0.8-8 variables with value labels in SPSS were transformed in factors with the labels in alphabetic order. In version 0.8-10 they seem to be ordered preserving the order corresponding to their numerical codes in SPSS. However I could not find a description of
2005 Sep 08
3
change in read.spss, package foreing?
Dear All, it seems to me that the function read.spss of package foreign changed its behaviour regarding factors. I noted that in version 0.8-8 variables with value labels in SPSS were transformed in factors with the labels in alphabetic order. In version 0.8-10 they seem to be ordered preserving the order corresponding to their numerical codes in SPSS. However I could not find a description of
2009 Sep 16
2
Teasing out logrank differences *between* groups using survdiff or something else?
R Folk: Please forgive what I'm sure is a fairly na?ve question; I hope it's clear. A colleague and I have been doing a really simple one-off survival analysis, but this is an area with which we are not very familiar, we just happen to have gathered some data that needs this type of analysis. We've done quite a bit of reading, but answers escape us, even though the question below
2005 Feb 17
5
Again: Variable names in functions
Hello, still I have difficulties with variable names in functions. I know the famous example form help for deparse/substitute but I will give a simpler one to explain my problem. I know from Reid Huntsinger (Tue, 8 Feb 2005 12:39:32 -0500) that: "Semantically, R is pass-by-value, so you don't really have the names, just the values. In implementation, though, R *does* pass names, in part