similar to: too many var in lm

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   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 All, I am writing a function to predict values based on a model. It works fine as long as the formula just uses regular variable names. I am having a problem when the variables are wrapped with a function call. For example: m <- lm(mpg ~ factor(cyl), data = mtcars) ## I get the column names using as.character(attr(terms(m), "variables"))[-1L] ## which gives the same column

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),

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

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

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

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

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

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

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, 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

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:

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))

I apprecaite the guidance Eik, that works great! I'm also wondering if you have any pointers for how I might stretch the color scale so that the max and min values are the same? Right now, the min is -0.064 and the max is something closer to 0.04. As you can see in what I sent, I tried adding: zmax1 = max(abs(m1)) ggplot(..., autoscale = FALSE, zmin = -1 * zmax1, zmax = zmax1) + ... to

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

Is there as way to initialize a vector (matrix) with an unknown length (dimension)? NULL does not seem to work. The lines below work with a vector of length 4 and a matrix of 4 x 4. What if I do not know initially the length/dimension of the vector/matrix? All I want is to add up (accumulate)? the vector and matrix as I go through the loop. Or, are there other ways to accumulate such vectors

Hi, My example code is this; x11<-data.frame(A=c(.6,.6,.6),B=c(.20,.20,.20),C=c(0.20,.20,.20)) 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()+ theme_showarrows()+geom_segment(size=.5)+ geom_text_viewport(x=c(.45,.27,.37),y=c(.32,.29,.22),label=as.expression("P_a","P_b","P_c"))

Dear All: good morning I need helps with the calculation of the *LC50* from the data below x<-c(0,0.3,0.7,1,4,10) y<-c(100,86,65,51.3,19.2,7.4) yxreg<-lm(y~x) any help will be highly appreciated. with many thanks abou ______________________ *AbouEl-Makarim Aboueissa, PhD* *Professor of Statistics* *Department of Mathematics and Statistics* *University of Southern Maine*