similar to: creating character vector

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")

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 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

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

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

Simple one here ... but can't get it to work ... for (i in 1:4){ paste("stuff",[i]),sep="") <- 3 + i } ls() rm(list=ls()) I just want it to create 4 new variables called stuff1, stuff2, stuff3, stuff4 with the corresponding assignments. I realise that there are more elegant functions but this is just a model of a bigger situation. Thanks Jim

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

Hi all, I would like to replace the for loop in the code below with a function to improve the speed and to make the script more efficient. The loop creates a vector of integers (x) with the probability of f for each integer. The length of f is variable, but sums to 1. I tried to use a function with optional arguments which did not work. Here is the code: f <- data.matrix(c(0.5,0.15,0.35))

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

Hello Eik: Thanks. I do not need to sample. Essentially, I have a do loop which produces 24 vectors of length of some length (say k=300) and 24 matrices of 300x300. Then, I simply need to? take the averages of these 24 vectors 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

Hello! I would like to do some tables for several variables and I would like to write a loop that does the table for each variable. I should also point out that my data set has several missing observations and sometimes the observations that are missing are not the same for all my variables. What I would like to do: table(StoreData$CompanyID, !is.na(StoreData$P2))

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

Hello I have a time-comsuming program which need to simplify, I have tested the annotated program as follow: > #define function which will be call > calsta <- function(c, n=100000) + { + i <- seq(from=0, length=c) + logx <- lchoose(NT-n, CT-i) + lchoose(n, i) + logmax <- max(logx) + logmax + log(sum(exp(logx - logmax))) + } > CT=6000 #assignment to CT >

Hi Anne, I would suggest to change the linear model to lm(BloodPressure~Age), as this model makes more sense in biological means (you would assume that age influences pressure, not vice versa) and also obeys the statistical assumption of weak exogeneity, that age can be measured without error, at least compared to error-prone bp measures. Cheers Am 18.04.2018 um 16:07 schrieb Gerrit Eichner:

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

I'd like to save some calculation outputs as a pdf, to incorporate with others in a document. I've tried pdf("filename") name_of_object_to_output dev.off() but it doesn't seem to work, appears that this pdf function is for graphics? Is there a way to output numerical objects to pdf? Thanks J Dr. Jim Maas University of East Anglia

Hi I have data in the following format Cort Day Animal 23 0 1 27 3 1 24 0 2 27 1 2 34 2 2 30 3 2 24 4 2 20 0 3 24 1 3 28 2 3 34 4 3 etc. It is measured across time(day) however no every individual is measured the same number of times. All I want to do is plot the Raw data and then run a line connecting the