search for: neyman

...ldn??t be removed, but then the test for group differences only tests for differences in intercept. This is in many cases not what was initially intended. Instead, what one wants is perhaps to determine values of the covariate at which the groups differ. I??ve seen a description of the Johnson-Neyman procedure (in Huitema (1980)), which allows to determine the so called regions of nonsignificance, which sounds a lot like what I want. The problem is I have very seldom seen it used (at least in my field of work), but unequal slopes is a common problem. (Searching the R-help archives, however,...

...neral information about the package: surv2sample provides various two-sample tests for right-censored survival data. Three main areas and corresponding methods are: * comparison of two survival distributions - surv2.logrank: weighted logrank tests and their combinations (max, sum) - surv2.neyman: Neyman's smooth test and its data-driven version - surv2.ks: Kolmogorov?Smirnov, Cram?r?von Mises and Anderson?Darling test * comparison of two cumulative incidence functions for competing risks data - cif: estimation and plotting of cumulative incidence functions - cif2.logrank: l...

Hi there, I want to generate a random point pattern using the Neyman-Scott cluster process using spatstat package in R. After running the following procedures, why i can not see any figures? > nclust <- function(x0, y0, radius, n) {return(runifdisc(n, radius, x0, y0))} > nclust function(x0, y0, radius, n) {return(runifdisc(n, radius, x0, y0))} > X <-...

...neral information about the package: surv2sample provides various two-sample tests for right-censored survival data. Three main areas and corresponding methods are: * comparison of two survival distributions - surv2.logrank: weighted logrank tests and their combinations (max, sum) - surv2.neyman: Neyman's smooth test and its data-driven version - surv2.ks: Kolmogorov?Smirnov, Cram?r?von Mises and Anderson?Darling test * comparison of two cumulative incidence functions for competing risks data - cif: estimation and plotting of cumulative incidence functions - cif2.logrank: l...

...aring the slopes of more than one regression line rather than the slopes of the predictors within the same fit.) I hope that makes sense. We really wanted to see if the predicted values at the ends of the 3 regression lines are significantly different... But I'm not sure how to do the Johnson-Neyman procedure in R, so I think testing for slope differences will suffice! Thanks to any who may be able to help! Doug Adams

Does anyone have any R code or suggestions on how to generate a population that follows a Neyman-Scott process? More specifically, I'd like to randomly generate both the parents and the children from Poisson distributions and the children locations from a bivariate normal onto an N by N grid. If the locations spill over outside the grid, then I'd like to reflect those locations back...

...les provided? IMHO the AIC is sufficient and the null hypothesis test is not well suited to the problem. As stated by Akaike (1974, A new look at the statistical model identification, IEEE Transactions on Automatic Control 19:716-723):"As was noticed by Lehman [this is the classic book on the Neyman-Pearson theory of hypothesis testing], hypothesis testing procedures are traditionally applied to the situation where actually multiple decision procedures are required. If the statistical identification procedure is considered as a decision procedure the very basic problem is the appropriate choic...

It seems as though 'symbol.For' does not work correctly. > library("foo") > add(3,4) [1] 7 > sym.add(3,5) Error in .Fortran(symbol.For("add"), as.numeric(a), as.numeric(b), c = as.numeric(0)) : "Fortran" function name not in load table The function 'add' is a R wrapper to a simple fortran 77 subroutine that adds two numbers. In

...(http://www.davidkraus.net/proptest/) has been recently released to CRAN. The package provides functions for testing the proportional hazards assumption in the Cox model for right censored survival data. Two types of tests for identifying nonproportional covariates are implemented: * data-driven Neyman type smooth tests (using both nested and all-subsets variant of the BIC), * tests based on the score process (KS, CM, and AD type, with the LWY simulation). Bug reports, comments or suggestions are welcome. Regards, David. -- David Kraus Institute of Information Theory and Automation Pod V...

For a sanitation project in Bangladesh I need to design a three stage sample survey to be representative of around 40 million people. I find myself suddenly with several challenges with which I struggle and would be gratefully for any help. As the questions are linked I kept them together rather than creating multiple posts 1) SURVEY DESIGN So far I designed mainly two stage cluster surveys but

I am trying to generate two dimensional random coordinates. For randomly distributed data I have simply used >xy<-cbind(runif(100),runif(100)) However I also want to generate coordinates that are more uniformly distributed, and coordinates that are more contagiously distributed than the above. Can anyone make any suggestions Thanks. Dr Terry Beutel Rangeland Scientist Animal

Dear Masters, first I'd like to wish u all a great 2011 and happy holydays by now, second (here it come the boring stuff) I have a question to which I hope u would answer: I run a logistic regression by glm(), on the following data type (y1=1,x1=x1); (y2=0,x2=x2);......(yn=0,xn=xn), where the response (y) is abinary outcome on 0,1 amd x is any explanatory variable (continuous or not)

I apologize if this question is not completely appropriate for this list. I have been using SAS for a while and am now in the process of learning some C and R as a part of my graduate studies. All of the statistical packages I have used generally yield p-values as a default output to standard procedures. This week I have been reading "Testing Precise Hypotheses" by J.O. Berger

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