similar to: Stratified random sample

Displaying 20 results from an estimated 3000 matches similar to: "Stratified random sample"

2008 Jul 20
3
enumerate subsets
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2008 Jan 28
2
sub-plot in a plot
From: lamac_k em hotmail.comTo: r-help-request em r-project.orgSubject: sub-plot in a plotDate: Mon, 28 Jan 2008 15:43:40 +0000 Dear all, how can I do these sub-plots in a plot (see file attached) in R. Best regards. Receba GR?TIS as mensagens do Messenger no seu celular quando voc? estiver offline. Conhe?a o MSN Mobile! Crie j? o seu!
2011 Mar 10
1
ANOVA for stratified cox regression
This is a follow-up to a query that was posted regarding some problems that emerge when running anova analyses for cox models, posted by Mathias Gondan: Matthias Gondan wrote: >* Dear List,*>**>* I have tried a stratified Cox Regression, it is working fine, except for*>* the "Anova"-Tests:*>**>* Here the commands (should work out of the box):*>**>*
2008 Jan 15
1
Anova for stratified Cox regression
Dear List, I have tried a stratified Cox Regression, it is working fine, except for the "Anova"-Tests: Here the commands (should work out of the box): library(survival) d = colon[colon$etype==2, ] m = coxph(Surv(time, status) ~ strata(sex) + rx, data=d) summary(m) # Printout ok anova(m, test='Chisq') This is the output of the anova command: > Analysis of Deviance Table
2012 Oct 13
4
Problems with coxph and survfit in a stratified model with interactions
I?m trying to set up proportional hazard model that is stratified with respect to covariate 1 and has an interaction between covariate 1 and another variable, covariate 2. Both variables are categorical. In the following, I try to illustrate the two problems that I?ve encountered, using the lung dataset. The first problem is the warning: To me, it seems that there are too many dummies
2005 May 04
1
stratified bootstrap with boot
Hello, I am new to R, and am having trouble getting the output I want from a stratified bootstrap. I didn't recieve a reply the first time I posted this question so I have tried to make it more clear. My data frame (denboot) is set up as follows: SITE cswa parea treat 1 BeanA 3 1.20 m 2 BeanBC 3 1.05 m 3 BeanD 1 0.93 m 4 BlackB 1 1.01
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
2005 Aug 28
2
stratified Wilcoxon available?
Dear All, is there a stratified version of the Wilcoxon test (also known as van Elteren test) available in R? I could find it in the survdiff function of the survival package for censored data. I think, it should be possible to use this function creating a dummy censoring indicator and setting it to not censored, but may be there is a better way to perform the test. Thanks, Heinz T??chler
2012 Oct 14
1
Problems with coxph and survfit in a stratified model, with interactions
First, here is your message as it appears on R-help. On 10/14/2012 05:00 AM, r-help-request@r-project.org wrote: > I?m trying to set up proportional hazard model that is stratified with > respect to covariate 1 and has an interaction between covariate 1 and > another variable, covariate 2. Both variables are categorical. In the > following, I try to illustrate the two problems that
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
2013 Apr 26
1
Stratified Random Sampling Proportional to Size
Hello R Experts, I kindly request your assistance on figuring out how to get a stratified random sampling proportional to 100. Below is my r code showing what I did and the error I'm getting with sampling::strata # FIRST I summarized count of records by the two variables I want to use as strata Library(RODBC) library(sqldf) library(sampling) #After establishing connection I query the data
2009 Jun 18
1
Stratified random sampling?
Rers: What is the preferred library/function for doing stratified random sampling from a dataset, given I want to control the number of samples (rather than the proportion of samples) per strata? Thanks! --j -- Jonathan A. Greenberg, PhD Postdoctoral Scholar Center for Spatial Technologies and Remote Sensing (CSTARS) University of California, Davis One Shields Avenue The Barn, Room
2007 May 17
1
Stratified Cox proportional Hazard Model
Hello everyone, I am a new user of R. Does anybody know how hazard ratios are extracted for each factor level in a stratified Cox proportional hazard regression model? I have a cancer data set where the variable ?differentiation? is a factor with three levels: poor, intermediate and good. I would like to extract the hazard ratio for each grade level and relate it to another prognostic factor.
2007 Sep 06
3
Survey package
Good afternoon! I'm trying to use the Survey package for a stratified sample which has 4 criteria on which the stratification is based. I would like to get the corrected weights and for every element i get a weight of 1 E.g: tipping design <- svydesign (id=~1, strata= ~regiune + size_loc + age_rec_hhh + size_hh, data= tabel) and then weights(design) gives
2005 May 26
1
Survey and Stratification
Dear WizaRds, Working through sampling theory, I tried to comprehend the concept of stratification and apply it with Survey to a small example. My question is more of theoretic nature, so I apologize if this does not fully fit this board's intention, but I have come to a complete stop in my efforts and need an expert to help me along. Please help: age<-matrix(c(rep(1,5), rep(2,3),
2008 Jan 19
1
(sem assunto)
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2009 Jul 12
2
strata -- really slow performance
I'm a bit confused why the following command is taking an extrodinarily long time (> 2-3 hours) to run on an 3.06ghz iMac (brand new). I'm trying to do a stratified random sample, drawing only a single value per UniqueID from the patch_summary data frame: uniqueids <- unique(patch_summary$UniqueID) uniqueids_stratasize <- c(1:length(uniqueids))*0+1
2006 Jun 18
1
Post Stratification
Dear WizaRds, having met some of you in person in Vienna, I think even more fondly of this community and hope to continue on this route. It was great talking with you and learning from you. Thank you. I am trying to work through an artificial example in post stratification. This is my dataset: library(survey) age <- data.frame(id=1:8, stratum=rep(
2008 Apr 07
2
basehaz and newdata
I am unable to get the basehaz function to apply a proportional hazards model to a new data frame. I replicated my specific situation with the example for coxph in the help, where I changed the x value of the first record from 0 to 1. Is there something incorrect in the syntax that I am using? Thanks in advance! test1 <- list(time= c(4, 3,1,1,2,2,3), status=c(1,NA,1,0,1,1,0),
2004 Feb 10
3
coxph error
R list: I am using a 'for' loop to run a number of different models (stratified by different variables) with coxph. The data becomes sparse when some strata are used causing the model to become unstable. The following error occurs and the analysis is terminated. >Error in fitter(X, Y, strats, offset, init, control, weights = weights, : (converted from warning) Loglik