search for: kappa

Hi, im little bit confused about Cohen's Kappa and i should be look into the Kappa function code. Is the easy formula really wrong? kappa=agreement-chance/(1-chance) many thanks christian ############################################################################### true-negativ:7445 false-positive:3410 false-negativ:347 true-positiv:772...

Dear R list, I have a function specifying my log-likelihood, and now I need to set the constraint that *alpha > kappa*, could anyone help me with setting this in my function? the function is defined as follows: mll <- function(param){ n <- length(x) psi <- numeric(n) psi[1] <- 1.0 a0 <- exp(param[1]); a1 <-exp(param[2]); b1 <- exp(param[3]); *alpha *<- exp(param[4]); *kappa *<-...

Greetings, I am a bit confused by the results returned by the functions: cohen.kappa {concord} classAgreement {e1071} when using a two-way table. for example, if I have an matrix A, and a similar matrix B (same dimensions), then: matrix A and B can be found: http://casoilresource.lawr.ucdavis.edu/drupal/files/a_40.txt http://casoilresource.lawr.ucdavis.edu/drupal/files/b_40.txt...

Hello, I?m looking for a way to measure the goodness of fit of my model with Cohen?s Kappa (scaling between 0 and 1). The kappa function does not give the results I?m looking for. Heres the code: z<-glm(x~y,binomial) kappa(z, exact = T) Does anyone know more? many thanks Christian -- _______________________________________________ Search for businesses by name, location, or phon...

Hi all, I have a list of 20000 data, and the list look like below. I wonder what is the simplest way to extract 'kappa' value (or 'xi' or 'alpha' for the matter) from each of the data. How can I simply code it without having to change the list to a dataframe first? Many thanks! $X19997 xi alpha kappa 784.7718640 165.4065141 -0.2709599 $X19998 xi alpha...

Hello, When evaluating different learning methods for a categorization problem with the (really useful!) caret package, I'm getting confusing results from the Kappa computation. The data is about 20,000 rows and a few dozen columns, and the categories are quite asymmetrical, 4.1% in one category and 95.9% in the other. When I train a ctree model as: model <- train(dat.dts, dat.dts.class, method='ctree',...

...the parameter could be located at the very extreme of the parameter space, or even 'beyond that' ? Example to express it and my very nontechnical 'beyond that': The von Mises distribution is a circular distribution, describing directional trends. It has a concentration parameter Kappa, with Kappa > 0. The lower kappa, the flatter the distribution, and for Kappa approaching 0, it converges into the uniform. Kappa shall be estimated [in a complex likelihood] through MCMC, with the problem that it is possible that there truly isn't any directional trend in the data at al...

Hi All, I am using fleiss kappa for inter rater agreement. Are there any know issues with Fleiss kappa calculation in R? Even when I supply mock data with total agreement among the raters I do not get a kappa value of 1. instead I am getting negative values. I am using the irr package version 0.70 Any help is much appreciated...

Dear R-user, Did anybody know how to calculate the kappa statistics of two vectors for the agreement? for example: a<-c(0,1,0,0,1,0) b<-c(0,1,1,0,0,1) I know the percent of agreement is 3/6, but how to get the kappa? [[alternative HTML version deleted]]

Dear all, I have a question on Cohen's kappa: Assume I have two datasets, one has 500 objects, 10 methods and the other, 1000 different objects, 20 different methods. Could I compare between the two datasets to conclude the 10 methods are more "concordant" than the 20 ones by looking at some output, for example, cohen.kappa{concord...

I have started using the circular package but it is not recognizing the function arrows.circular. I attempted to use the example provided in the circular manual. Here is the example code using the circular package: plot(rvonmises(10, circular(0), kappa=1)) arrows.circular(rvonmises(10, circular(0), kappa=1)) arrows.circular(rvonmises(10, circular(0), kappa=1), y=runif(10), col=2) arrows.circular(rvonmises(10, circular(0), kappa=1), y=runif(10), x0=runif(10, -1, 1), y0=runif(10, -1, 1), col=3) My error is: Error: could not find functio...

Dear list, I'm migrating a project from Matlab to R, and I'm facing a relatively complicated problem for nls. My objective function is below: >> objFun <- function(yEx,xEx,tEx,gamma,theta,kappa){ yTh <- pdfDY(xEx,tEx,gamma,theta,kappa) sum(log(yEx/yTh)^2) } The equation is yTh=P(xEx,tEx) + noise. I collect my data in: >> data <- data.frame(xEx,tEx,yEx) And I do the nls: aux <- nls( ~ objFun(yEx,xEx,tEx,gamma,theta,kappa), data=data, start=list...

...em. But the point outside the box was test, and I got error. My program and the error follows. This program depends on CircStats package. Anyone has any idea about this? Thanks in advance. Li #################### source code ################################### Dk2<- function(pars,theta) { kappa<- pars[1]; mu<- pars[2]; IoK<- besselI(kappa, nu=0); res<- besselI(2*kappa, nu=0)/2/IoK^2 - mean(exp(kappa*cos(theta-mu)))/IoK; if(is.na(res)||is.infinite(res)){ print(pars); # assign("Theta", theta, env=.GlobalEnv); } return(res); } mse.Dk2<- function(pars,...

Dear list, I calculated the kappa-accuracy for two differnt classifications. How can I test now the two kappa-value for significance? thanks, Mark ..................................................................... Markus Schwarz Wissenschaftliche Mitarbeiterin Eidg. Forschungsanstalt WSL Forschungsprogramm Musterland Z??rcherst...

Is there a function that calculates the inter-rater agreement index (kappa) in R? Thanks ../Murli [[alternative HTML version deleted]]

Hallo all, I am looking for an R implementation of the four parameter kappa distribution (cdf, pdf, quantile, and ransom numbers), or at a minimum, the generalized logistic distribution. Any suggestions? Thank you very much, Serguei

Dear R-users I need to calibrate kappa, rho, eta, theta, v0 in the following code, see below. However when I run it, I get: y <- function(kappahat, rhohat, etahat, thetahat, v0hat) {sum(difference(k, t, S0, X, r, implvol, q, kappahat, rhohat, etahat, thetahat, v0hat)^2)} > nlminb(start=list(kappa, rho, eta, theta, v0), objective...

...e following message: # "In if (is.finite(lower)) { :the condition has length > 1 and only the first element # will be used" # And, in fact, correct multiple values are not returned. ######################################################## ASEPF<- function(y, theta, sigma, alpha, kappa){ loww<-((theta - y)/(sigma* kappa))^alpha upp<- (kappa *(y - theta)/sigma)^alpha k<- 1/(1 + kappa^2) a<- 1/alpha integrand<- function(y){y^(a-1)* exp(-y)/gamma(1/alpha)} GL<- integrate(integrand, lower = loww, upper= Inf)$value GU<- integrate(integrand, lower = upp, up...

Dear R-colleagues, I am quite a newbie to R fighting my stupidity to solve a probably quite simple problem of generating artificial data with defined features. I am conducting a study of inter-observer-agreement in child-bronchoscopy. One of the most important measures is Kappa according to Fleiss, which is very comfortable available in R through the irr-package. Unfortunately medical doctors like me don't really understand much of statistics. Therefore I'd like to give the reader an easy understandable example of Fleiss-Kappa in the Methods part. To achieve this,...

...matrix(0,nrow=no.obs) SigV <- SigV.kal <- matrix(0,ncol=no.state,nrow=no.state) SigW <- SigW.kal <- matrix(0,nrow=no.obs,ncol=no.obs) x <- rep(0,n) A <- B <- G.B <- numeric(matur[no.obs]) Z <- matrix(ncol=n,nrow=no.obs) kappa <- 0.97 theta <- 0.07 sigma <- 0.005 lambda <- -0.162 beta <- sigma*lambda rho <- 0.5*sigma^2*lambda^2 Q <- sigma^2 R <- sigma^2*0.125 rho <- 0.5*lambda^2*sigma^2 Xav[1,] <- rep(1,n)...