similar to: The plot of qqmath

Hello, I've had no luck finding an R package that has the ability to estimate a Tobit model allowing for heteroskedasticity (multiplicative, for example). Am I missing something in survReg? Is there another package that I'm unaware of? Is there an add-on package that will test for heteroskedasticity? Thanks for your help. Cheers, Alan Spearot -- Alan Spearot Department of Economics

Hi, I'm trying to aggregate date values using the aggregate function. For example: aggregate(data,by=list(weekdays(LM),months(LM)),FUN=length) I would also like to aggregate by year but there seems to be no years() function. Should there be one? Is there any alternative choice? Also, a hours() function would be great. Any tip on this? Thanks in advance! S?rgio Nunes

Hi there, I'm writing a function that calculates the probability of different outcomes of dice rolls (e.g., the sum of the highest three rolls of five six-sided dice). I'm using the "combinations" function from the "gtools" package, which is great: it gives me a matrix with all of the possible combinations (with repetitions allowed). Now I want to count the number

Hello, I have a small statistics question, and as I'm quite new to statistics and R, I'm not sure if I'm doing things correctly. I am looking at two quantitative variables (x,y) that are correlated. When I divide the data set according to a categorical variable z, then x and y are more poorly correlated when z = A than when z = B (see attached figure). In fact x and y are two

Hello, I am trying to get the P values from the output of a summary for lm. lm <- lm(y ~ age + sex) s <- summary(lm) I thought that I might be able to get them using a combination of scan, grep and sub. But I got stuck on the first step - being able to process "s" as a text string. I could perhaps write it to file than scan it back but there is probably an easier way to do

Having solved this problem, I am posting this so that the next time I search for how to do this I will find an answer... Using qqmath(..., groups=num) creates a separate qq distribution for each group (within a panel). Using the 'col' or 'pch' argument does not (usually) work because panel.qqmath sorts the data (but not 'col' or 'pch') before plotting. Sorting

Hi, Don't have a clue what teh following error message generated by this function call: qqmath( ~val|ind,data = xx ,distribution = function(p){ qt(p,df=20)} ,ylab="Sample Quatinles" ,xlab="Theoretical Quantiles" ,panel=function(x,y) { panel.qqmathline(y , distribution=function(p) qt(p,df=20)

Hello, I can't seem to make qqmath plot text. v <- rnorm(8) qqmath(~v) # this is ok, but qqmath(~v, panel=function(x, y) { points(x, y) text(0, 0, 'print me', cex=2)}) isn't ok. The axis frame is printed properly (ie, as in qqmath(~v)), but neither 'print me' nor the points show up on the graph. I can, however, see the upper half of the word 'me' in the

David, Duncan, > Hi > > Following on David's rate argument > > try (with modifications of pch and grid) > > rate <- 1/4 > shape = 8 > rate = c(rep(1/4,100),rep(1/3,100)) I don't think the problem is related to the rate argument, which can well be vectorized, as is the case for a number of arguments in distrib functions in R (note that you are redefining it

In qqmath, how would one go about having 'distribution' change with panel.number? I've tried set.seed(1) mydata <- data.frame(ind = factor(rep(2:4, each = 100))) mydata$val <- rt(300, df=rep(2:4, each = 100)) plot<-qqmath(~ val | ind, layout=c(3,1), data = mydata, prepanel = function(x, distribution, ...) {

Hi out there, I am trying to fit a species accumulation curve (increase in number of species known vs. sampling effort) for multiple regions and several bootstrap samples. The bootstrap samples represent different arrangements of the actual sample sequence. I fitted a series of nlme-models and everything seems OK, but since the observations are correlated I tried to include some correlation

I have an interesting lme - problem. The data is part of the Master Thesis of my friend, and she had some problems analysing this data, until one of her Jurors proposed to use linear mixed-effect models. I'm trying to help her since she has no experience with R. I'm very used to R but have very few experience with lme. The group calls of one species of parrot were recorded at many

Dear group, I tried to generate labels for every second tick in lattice (qqmath). Version: 0.14-16 Date: 2006/12/01 R version 2.4.1 (2006-12-18) An example: library(lattice) numy=100 y=runif(numy,min=0,max=1) sig=0.05 numsig=length(which(y<sig)) tck.no=11 # number of ticks tcks=1:tck.no labl=as.character(0.1*tcks-0.1) # label for all ticks labl[seq(2,tck.no-1,2)]="" # delete

Does the 'groups' option on qqmath just color the points differently in the main distribution or does it actually overlay separate quantile plots for each subset? I would like to be able to do the latter. --Rich Richard Kittler AMD TDG 408-749-4099

Hello ALL! Can anyone tell me how to specify qqmath() function with distribution qgamma? In help it is bit vague how to pass shape and scale parameters for gamma. Thank you in advance. Best, PM

The data are not normally distributed when untransformed and I'm trying various transformations to see if any would be appropriate to use. The lattice book (fig. 3.10) shows a 2-sample Q-Q plot with an abline but the code for the figure does not include the line. I'd appreciate a pointer to a reference on how to add an abline to a one-sample qqmath() plot in lattice. Rich

Dear R list, The code below puts qq-plots for two of three groups on the one plot. However the legend includes all three groups, ie the auto.key ignores the subset instruction. Is there an easy way to get around this, so that only those groups plotted are included in the legend? y1<-rnorm(100); y2<-rnorm(100)+1; y3<-rnorm(100)+2; y<-c(y1,y2,y3)

Hi everyone, I'm interested in the analysis of spatial data, and I'm trying out several R-packages. Today I was attempting to use the package vardiag (version 0.1): >> library(vardiag) >> rs4.vo <- varobj(rs4[,2:4],trace=2) >[1] 1 >Error: couldn't find function "nlregb" so far I know "nlregb" is a S-plus function for optimization, so this

One of many scripts to produce 4 lattice plots on one page keeps throwing an error. I've tried manipulating the file to eliminate the error, but have not been able to do so. The error is: > source('bicarb.R') Error in source("bicarb.R") : bicarb.R:15:1: unexpected symbol 14: 15: hco33 ^ The 'h' is in column 0 so the caret would be column -1, but it's

This is the qqmath example from the lattice package. I added the scales to the example. I would like to switch the axis and not sure how? Meaning I would like the "height" on the x-axis and the probability on the y-axis. Will you show me the correct syntax for this switch thanks. qqmath(~ height | voice.part, aspect = "xy", data = singer, prepanel =