search for: vettorazzi

Dear list   I have 5 markers that can be used to detect an infection in combination. Could you please advise me how to use functions in ROCR/ other package to produce the ROC curve for a combination of markers?   I have used the following to get ROC statistics for each marker. pred <- prediction(y$marker1, y$infectn) perf <-performance(pred,"tpr","fpr")

Hi, I have a vector or random variables and I'm estimating the density using "bkde" function in the KernSmooth package. The out put contains two vectors (x and y), and the R documentation calls y as the density estimates, but my y-values are not exact density etstimates (since these are numbers larger than 1)! what is y here? Is it possible to get the true estimated density at each

Hello, It might be an easy question but if you have many variables to fit in the lm function, how do you take all without specifying var1+var2+...+var2100 in the terms parameter in response ~ terms? Cheers, Carol

Hi all, I have two vectors (columns) called "efinal" and "efinal 2". I want to plot them on the same plot and "draw" a shaded area beween the two lines using function polygon I have tried all but I don ?t understand the polygon area, can you help me with examples? plot(efinal,type="l",ylim=range(min(efinal2),

Hey all, In order to test if a marker is a risk factor, I built two models (using cox proportional hazard model). One model included this marker, and the other is not. Then, I use R package risksetROC to test how much predictive value did the marker add to this model. I get two C statistics by analyzing the linear predictors of the two models into this package. The qustion is How to test if two

I noticed that the text() command adds text to a plot. Is there a way to either make the plot blank or add text to a "blank sheet". I would like to "plot" a page that contains just text, no plot lines, labels, etc. Suggestions? Kevin [[alternative HTML version deleted]]

Hi, i want to construct a data set similar to "AirPassengers". Its attributes are following. > attributes(AirPassengers) $tsp [1] 1949.000 1960.917 12.000 $class [1] "ts" How Can I construct a data set similar to it having same class and attributes. Thanks -- Amar Kumar Nandan ?:nandan.amar at gmail.com http://aknandan.co.nr

Hi All, I am trying to lable the y-axis on my scatterplot with the following: "Soil moisture content (m3m-3)" I am using the following coding for plotting the graph: plot(soilmoisture~gradientlevel, xlab="Levels of droughting gradient", ylab="Soil moisture content (m3m-3)", bty="l", font.main="2", pch=16, las=1, cex.lab="1.13") I have

Say I have a list of variables,  listVar <- list(age,sex) I am looking for a way to either 1- create a vector c("age","sex") from it, or 2- get the names one by one in a for loop such as these     a)  for (i in 1:length(listVar)) rownames(result)[i] <- ???     b)  for(i in listVar) print (variable's name) Any help much appreciated. [[alternative HTML version

Dear List members, I really, like the feature that one can call R functions with mathematical expressions, e.g. curve(x^2, 0, 1) I wonder, how I can construct in a simple way a function like mycurve = function (expr) {...} such that that a call mycurve(x^2) has the same effect as the call curve(x^2, -100,100) Below is some code that works, but it seems much to complicated: it first

D'oh! Thanks for pointing this out. I blame caffeine depletion at the time... -pd > On 4 Dec 2017, at 15:48 , Eik Vettorazzi <E.Vettorazzi at uke.de> wrote: > > reading ?plotmath you might notice that "_" isn't the propper syntax for > subscripts. This will work: > > ggtern(data=x11,aes(A,B,C,xend = c(0.7,.00,0.7),yend = > c(.30,.50,.0),zend =c(.0,.50,0.3)))+ > geom_point()+ &g...

Dear users, 1. Is there a way to create a movie file to play a sequence of single frames (e.g. plots) at a specified time delay between frames? 2. If making a movie file is not possible, then how can I incorporate in a loop some delay between the frames to be plotted so I can change the playing speed? Sorry if this questions was already in the forum, but I couldn?t find it. Thanks in advance

Hi, my problem is as follows: I have a matrix of two rows like this: 2 2 3 4 4 4 5 5 6 1 1 2 1 3 3 2 1 1 Can I apply something like "group by" in sql? What I want to achieve is the some of second row for each unique entry of first row: 2 -> 2 (=1+1) 3 -> 2 4 -> 7 (=1+3+3) 5 -> 3 (=2+1) 6 -> 1 Thanks!! Henning

Is there a way to convince R to create a character vector without using the quotes? This works ex1 <- c("first","second") but when I try this it doesn't ext <- as.character(c(first,second)) it complains. I have many variables to put into character vectors so dispensing with the quotes would be useful. Thanks Jim =============================== Dr. Jim Maas

Hi Eik, thank you so much - it works perfectly! Thank you and best wishes Alain   Eik Vettorazzi <E.Vettorazzi@uke.de> hat am 6. Februar 2013 um 17:01 geschrieben: > Hi Alain, > here is a one-liner for a df without the rowSum column > > df<-data.frame(id=c("x01","x02","x03","x04","x05","x06"),a=c(1,2,NA,4,5,6),b=...

...ors and matrices: x=(x1+x2+...+x24)/k y=(y1+y2+...+y24)/k I am just looking for ways to do this in a do loop, which requires initialization (to 0's) of x and y. My struggle is not knowning length of x until x1 is produced in the first of the loop. Thanks. Steven On 2/28/2024 6:22 PM, Eik Vettorazzi wrote: > Hi Steven, > It's not entirely clear what you actually want to achieve in the end. > > As soon as you "know" x1, and assuming that the different "xi" do not > differ in length in the real application, you know the length of the > target vector. &...

...mailing list -- To UNSUBSCRIBE and more, see >> https://stat.ethz.ch/mailman/listinfo/r-help >> PLEASE do read the posting guide >> http://www.R-project.org/posting-guide.html >> and provide commented, minimal, self-contained, reproducible code. >> > > -- Eik Vettorazzi Department of Medical Biometry and Epidemiology University Medical Center Hamburg-Eppendorf Martinistrasse 52 building W 34 20246 Hamburg Phone: +49 (0) 40 7410 - 58243 Fax: +49 (0) 40 7410 - 57790 Web: www.uke.de/imbe -- _____________________________________________________________________...

I am writing a program in which I would like to take in a formula, change the response (Y) variable into something else, and then pass the formula, with the new Y variable to another function. That is, I am starting with formula <- Y~X1+X2+X3 and I'd like to do something like Y <- formula$Y newY <- f(Y) lm(newY~X1+X2+X3) So far, it seems that my

Hi, I'm using read.table in a loop, to read in multiple files. The problem is that when a file is missing there is an error message and the loop is broken; what I'd like to do is to test for the error and simply do "next" instead of breaking the loop. Anybody knows how to do that? Example: filelist <- c("file1.txt", "file2.txt",

I wish place the following axis label in such a manner that some of the text is plain and the scientific name is in italics (i.e. a mixture of two font types) Using plot: mtext("Total Landings of Pecten maximus (tonnes)",font,=3, side=2, line=3) makes everything italic, but how do I apply the font change to only "Pecten maximus"? Rgds Phil