search for: cutpoint

Below is a diff to vcut.c and its vcut.1 manpage, which - rewrites the manpage in the mdoc(7) markup as offered in my previous message, and while there: - drops the [] around cutpoint as it is _not_ optional - adds the [] around [+] as it _is_ optional - drops the argument name difference between "cutpoint" and "cuttime" - adds the usage sentence about "." output names to the manpage - tweaks the usage printf accordingly Jan diff --git a/vcut/vc...

Dear List, Does anybody no how to compare mean survival times for two (more) groups in R? What test statistics should I use? Thank you very much! Joe [[alternative HTML version deleted]]

Hola a todos, Al ejecutar el código que veis más abajo:  library(OptimalCutpoints)prediccion<-c(0.49165923,0.52759793,0.30213400,0.33468349,0.14979703,0.47401846,0.52216404,0.42018794,0.92168073,0.76893929,0.83362668,0.38251162,0.70803701,0.49165923,0.94462558) real<-c(0,1,0,0,0,0,1,1,1,1,1,0,1,0,1)datos_OPTIMO<-cbind(prediccion,real) cutpoint1 <- optimal.cutpoints(...

.... ### They claim that one can recode an n-chotomy into n-1 dichotomous ### indicators. Each observation in the original dataset begets n-1 ### lines in the augmented version. After creating the dichotomous ### indicator, one uses an ordinary dichotomous logit model to ### estimate parameters and cutpoints for an ordinal logit ### model. Cole, et al., are very clear. ### There is an additional benefit to the augmented data approach. ### One can explicitly test the proportional odds assumption by checking ### for interactions between the included independent variables and the ### "level" o...

...-Test, t = 2.2") linepos <- 2.2 abline(v = linepos) # I try to fill a polygon right of the vertical line: # max(x) - linepos (in this case, 2.2) / scale (0.1) # results in the last 38 elements of x and y. # so I take the last 38 elements of x and y and try to # draw a polygon underneath: cutpoint <- (max(x) - linepos) / scale xt <- x[(length(x)-cutpoint):length(x)] yt <- y[(length(y)-cutpoint):length(y)] # draw the polygon polygon(xt, yt, density = 10 ) As you can see in the result, this is not what I want; some area above the line gets shaded, but not below. Can someone tell...

..., since the documentation is insufficient in this case. According to him Jarrod (forums), the a posteriori means of the coefficients of the covariates are the probit scale. According to my study, these coefficients are the scores of standard normal distribution. More scores should not correspond to cutpoints? In this case, we would have j (response variable categories) -1 cutpoints, ie, two cutpoints. The output shows me only one cutpoint. How can then calculate the probabilities with only one cutpoint? According to the documentation (Vignettes, page 22), if P (y = k) = F (yk | l (vlatente), 1) - F (y...

...e you found it or a similar function? thank you, Sincerely, Friederike "The title says it all really; I am looking for a function along the lines of cutpt.coxph as described in "Survival Analysis Using S" (Tableman and Kim), Chapter 6. As may be guessed, the function optimises the cutpoint of a continuous variable for cox proportional hazard modelling. I can't find it, or any similar function, on CRAN. Alternatively, perhaps there is a way of extracting the likelihoods from the output of coxph." Dr. med. Friederike Schneider Assistenz?rztin Klinikum der LMU Campus Gros...

...I'm writing some R code that requires a massive amount of looping and would ideally like to write it so that it avoid the use of "for" loop ... however I'm having some trouble. Very briefly, the basic idea is to implement a binary partitioning algorithm to determine the optimal cutpoint based on deviance measures obtained from likelihood estiamtes. This is in the geo-spatial context so I'm actually using the geoRglm package to obtain this likelihood fit. I initially use the "variog" function to help specify the initial parameter values passed to "likfit"...

Skipped content of type multipart/mixed-------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 189 bytes Desc: Digital signature Url : http://westfish.xiph.org/pipermail/vorbis-dev/attachments/20040618/e7bee431/attachment.pgp

How does one use the vcut from Vorbis-tools package? I tried to enter samples, miliseconds, seconds, h:mm:ss as cut point, but nothing worked (I even tried to enter 1 as cutpoint, but I always got "Cutpoint not within stream." message)... I'm doing this on Windows, if it matters... -- Jernej Simoncic, jernej.simoncic@guest.arnes.si http://www2.arnes.si/~sopjsimo/ ICQ: 26266467 Organizations can grow faster than their brains can manage them in relation to...

...that the first 19 observation has been sent to the left side of the tree and one observation to the right. This is correct when we observe goodness (the maximum is the last element of the vector). The thing i really don't understand is the direction vector. # direction= -1 = send "y< cutpoint" to the left side of the tree # 1 = send "y< cutpoint" to the right What does it mean ? In the example here considered we have > sign(lmean) [1] 1 1 -1 -1 -1 -1 -1 1 1 1 -1 -1 -1 -1 -1 -1 -1 -1 -1 Which is the criterion used ? In my opinion we should have all the values equal...

...ns for manual or pre-made solutions. Example: set.seed(2) x <- matrix(rnorm(1000),ncol=10) #obviously no real clusters here... row.hclust <- hclust(dist(x)) row.dendro <- as.dendrogram(row.hclust) heatmap(x, Rowv=row.dendro) row.cut <- cutree(row.hclust,3)[row.hclust$order] cutpoints <- which(row.cut[-1]!=row.cut[-length(row.cut)]) ymin <- par("usr")[3] #in general incorrect ymax <- par("usr")[4] #in general incorrect for (i in cutpoints){ thisy <- ymin + (ymax-ymin)*(i-1)/nrow(x) abline(h=thisy,lw=3) }

R 2.1.1 Win 2k Would someone suggest a method (or methods) that can be used to determine ntile cutpoints of a vector, i.e. to determine values that can be used to divide a vector into thirds such as 0-33 centile, 34-66 centile, 67-100 centile. If for example I had a vector: 1,2,3,4,5,6,7,8,9 and wanted to divide the vector into thirds I would have cut-points of 3, and 6. Thanks, John John Sorkin M....

Dear List: I have searched the archives and my R books and cannot find a method to transform a continuous variable into a binary variable. For example, I have test score data along a continuous scale. I want to create a new variable in my dataset that is 1=above a cutpoint (or passed the test) and 0=otherwise. My instinct tells me that this will require a combination of the transform command along with a conditional selection. Any help is much appreciated. Thanks, Harold [[alternative HTML version deleted]]

...k this is an error. * accuracy<-length(which(pred==z))/length(z) accuracy rocpreds<-prediction(pred,z) auc<-performance(rocpreds,"auc")@y.values output<-c(int,slope,cutmid,accuracy,auc) names(output)<-c("Intercept","Slope","CutPoint","Accuracy","AUC") return(output) } y<-fitglm(.05,1) y nreps <- 500; output<-data.frame(matrix(rep(NA),nreps,6,ncol=6)) mysigma<-.5 mytau<-.1 i<-1 for(j in 1:nreps) { output[j,1:5]<-fitglm(mysigma,mytau) output[j,6]<-j } names(outp...

Dear forumites As a newbie I try to figure out whether R can do a certain job quicker than other programs and it seems so, but I don't find a solution to a seemingly simple problem: I have built a matrix of distance with as.matrix(dist()) with several hundred rows and columns 1 2 3 4 1 0 1.3 1.6 2.1 2 1.3 0

Dear all, I have two variables, y and x. It seems that the relationship between them is Piecewise Linear Functions. The cutpoint is 20. That is, when x<20, there is a linear relationship between y and x; while x>=20, there is another different linear relationship between them. How can i specify their relationships in R correctly? # glm(y~I(x<20)+I(x>=20),family = binomial, data = point) something like this? Tha...

...entiv<-sentiv[2] sentiv specs<-performance(rocpreds,"spec")@y.values specs<-slot(fp2,"y.values")[[1]] specs<-specs[2] specs output<-c(int,slope,.5,accuracy,auc,sentiv,specs) names(output)<-c("Intercept","Slope","CutPoint","Accuracy","AUC","Sentivity",Specificity") return(output) } y<-fitglm(.05,1) y The code runs without the sentiv and specs but when I remove the loop i can get the sensitivity and spec. values ??? [[alternative HTML version deleted]]

...an attribute on NULL and > attach( rt ) Error in attach(rt) : attach only works for lists and data frames the code that I use to build the matrix is : # break up the classes into cats and test for departure from zero signif <- symnum(fit3sls[[2]]$residuals, corr = FALSE, na = FALSE, cutpoints = c(-5,.1,.2,.3,.4, 5), symbols = c("A","B","C","D","E")) rt <- noquote( cbind( fit3sls[[2]]$residuals, signif ) ) colnames(table) <- c("resid","group") boxplot( resid ~ signif, data = rt ) which doesn't work....

...e")[unclass(iris$Species)], lower.panel=panel.cor, splitvar=iris$Species) ------------ #here the code I tried to implement to show the significance levels test <- cor.test(x, y, ,use="complete.obs") Signif <- symnum(test$p.value, corr = FALSE, na = FALSE, cutpoints = c(0, 0.001, 0.01, 0.05, 0.1, 1), symbols = c("***", "**", "*", ".", " ")) -- View this message in context: http://www.nabble.com/display-p-values--and-significance-levels-tp21769056p21769056.html Sent from the R help mailing li...