similar to: Normality test

I don't know from the nortest package, but it should ***always*** be the case that you test hypotheses H_0: The data have a normal distribution. vs. H_a: The data do not have a normal distribution. So if you get a p-value < 0.05 you can say that ***there is evidence*** (at the 0.05 significance level) that the data are not from a normal distribution. If the nortest package does

Hi all, I am trying to test wheater the distribution of my samples is normal with QQ plot. I have a values of water content in clays in around few hundred samples. Is the code : qqnorm(w) #w being water content qqline(w) sufficient? How do I know when I get the plots which distribution is normal and which is not? Thanks, m [[alternative HTML version

Hi, this is my first help request so please bear with me. I've been running some normality tests using the nortest package. For some of my datasets the Cramer-von Mises normality test generates an extremely high probability (e.g., 1.637e+31) and indicates normality when the other tests do not. Is there something I'm misunderstanding or potentially a bug in the code? Below are the

Dear Sir, I have data, coming from tests, consisting of 300 values. Is there a way in R with which I can confirm this data to 68-95-99.8 rule or three-sigma rule? I need to look around percentile ranks and prediction intervals for this data. I, however, used SixSigma package and used ss.ci() function, which produced 95% confidence intervals. I still am not certain about percentile ranks

I have written a function to emulate minitab's QQ plotting output (with SW test and AD test results on the graph): mtab.norm<-function(x) { library(nortest) library(lattice) x<-as.numeric(x) x<-as.vector(x) plot.ht<-4.6 plot.wd<-4.6 pt.ht=plot.ht/5 txt.sz<-(plot.ht/7.5) X11(width=plot.wd, height=plot.ht, bg='gray96') qqplot(x, pch=16, cex=pt.ht,

Hi, I'm a newbie and i am unable to use lillie.test in nortest I have a message: "Couldn't find function "lillie.test" I am under windows2000 with R1.8.1 nortest is listed with .packages(TRUE) How to do to use lillie.test function? Laurent Houdusse Analyste Programmeur

I believe there to be a bug in the cvm.test module of the nortest package authored by Juergen Gross. I do not know how to contact the author directly. I've been running some normality tests using the nortest package. For some of my datasets the Cramer-von Mises normality test generates an extremely high probability (e.g., 1.637e+31) and indicates normality when the other tests do

Hi, R friends. I had some difficulty with the following code: qqnorm(freq, log='y') qqline(freq) as the line drawn was seemingly random. The exact data I used appears below. After wandering a bit within the source code for "abline", I figured out I should rather write: qqnorm(freq, log='y') par(ylog=FALSE) qqline(log10(freq)) par(ylog=TRUE)

I have compiled a package in R which performs the Doornik-Hansen (1994) version of the omnibus normality test (a finite sample version of the Jarque-Bera test), including a variation which allows for weak dependence rather than independence of the variable(s) in question. I have tried to contact the compiler of the "nortest" package (which deals with the same subject) but have not

Hi there, I am trying to perform different normality tests in R. I have no problem when I use Shapiro.test( ). However, when I try to use any normality tests from the Nortest package, I kept getting this error " Error in read.table(source, header = T, fill = T) : 'file' must be a character string or connection". I have no idea why because there was no problem with

Hi, I have a small set of data on which I have tried some normality tests. When I make a histogram of the data the distribution doesn't seem to be normal at all (rather lognormal), but still no matter what test I use (Shapiro, Anderson-Darling,...) it returns a very small p value (which as far as I know means that the distribution is normal). Am I doing something wrong here? Thanks Pieter

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In addition to the previous email: What plots would you suggest in addition to density / histogram plots and how can I produce them with R ? Perhaps one of you has an example ? Thanks a lot, Ralf

I have a data vector x. When I try qqline(x) I get the following error: Error in int_abline(a = a, b = b, h = h, v = v, untf = untf, ...) : plot.new has not been called yet And a blank plot appears. Can anybody help? What am I doing wrong? Thanks, Scotty _________________________________________________________________ Contest [[alternative HTML version deleted]]

Hi, I'm trying to create a qqplot with reference to a Weibull distribution including a reference line. This is my current code: lights.data <- scan("lights.dat") #Generate Weibull quantiles prob.grid <- ppoints(length(lights.data)) prob.quant <- qweibull(prob.grid , 1.5,4) #Draw QQ plot qqplot(prob.quant,lights.data) #add red reference line qqline(lights.data,col = 2)

Hi All, I want to convert a video file which is located at the Amazon-S3 Store, through ffmpeg. How can it b possible? please help me if anyone have any idea. for ex:- is it possible to execute following command:- system "ffmpeg -i

I am a beginner in R, so please don't step on me if this is too simple. I have two data sets datax and datay for which I created a qqplot qqplot(datax,datay) but now I want a line that indicates the perfect match so that I can see how much the plot diverts from the ideal. This ideal however is not normal, so I think qqnorm and qqline cannot be applied. Perhaps you can help? Ralf

I think qqline does not do exactly what it is advertised to do ("`qqline' adds a line to a normal quantile-quantile plot which passes through the first and third quartiles."). Consider the graph: tmp <- qnorm(ppoints(10)) qqnorm(tmp) qqline(tmp) The line (which I expected go through all the points), has a slightly shallower slope than does the points plotted by qqnorm. I think

Hi, I'm trying to run an anderson-darling test for normality on a given variable 'Y': ad.test(Y) I think I need the 'nortest' package, but since it does not appear in any of the Ubuntu repositories for 2.10.1, I am wondering if it goes by the name of something else now? Thanks -- View this message in context:

Hi, We could use qqplot to see how two distributions are different from each other. To show better how they are different (departs from the straight line), how is it possible to plot the straight line that goes through them? I am looking for some thing like qqline for qqnorm. I thought of abline but how to determine the slope and intercept? Best wishes, Carol