search for: xbars

Hello, I have written a function that demonstrates the CLT by generating samples following the exponential distribution, calculating the means, plotting the histogram, and drawing the limiting normal curve as an overlay. I have the title of each histogram state the sample size and rate (1/theta) for the exponential (the output is actually 4 histograms), but I can't get the greek letter theta

Hi, there I'm trying to plot what is returned from a call to tapply, and can't figure out how to do it. My guess is that it has something to do with the inclusion of row names when you ask for the values you're interested in, but if anyone has any ideas on how to get it to work, that would be stellar. Here's some example code: y1<-rnorm(40, 2) x1<-rep(1:2, each=20)

I am new to R. I want to graph group data using a "Traditional Bar Chart with Standard Error Bar", like the kind shown here: http://samiam.colorado.edu/~mcclella/ftep/twoGroups/twoGroupGraphs.html Is there a simple way to do this? So far, I have only figured out how to plot the bars using barplot. testdata <- scan(, list(group=0,xbar=0,se=0)) 400 0.36038 0.02154 200 0.35927

Hi, I've had a quick look through the package list, and unless I've missed something, I can't seem to find anything that will do I-MR / Xbar-R / Xbar-S control charts ? Assuming there is something out there, can anyone point me in the right direction ? Thanks ! TIm

Hello, I have no experience with I-MR charts but a google search found package qcc. Maybe it's what you're looking for. Hope this helps, Rui Barradas Em 08-07-2017 09:07, Tim Smith escreveu: > Hi, > > I've had a quick look through the package list, and unless I've missed > something, I can't seem to find anything that will do I-MR / Xbar-R / > Xbar-S control

I am having issues with the following: (muhat = 1/n^2(sum of all the xi's) ) essentially if xbar = the sample mean, muhat = sample mean but square the n. Question: Use R to run a Monte Carlo simulation which compares the finite-sample performance of xbar and muhat. Specifically generate 1000 samples n=30 from a standard normal distribution. For each sample calculate xbar and muhat. I have

Dear all, I am a newbie in R and could not find help on this problem. I am trying to plot an histogram with probabilities in the y axis. This is the code I am using: #TLC uniform n=30 mi=1; mx=6 nrep=1000 xbar=rep(0,nrep) for (i in 1:nrep) {xbar[i]=mean(runif(n,min=mi,max=mx))} hist(xbar,prob=TRUE,breaks="Sturges",xlim=c(1,6),main=paste("n =",n), xlab="Média",

Hi Folks, I have data that looks like this: freq gender xBar 1000 m 2.32 1000 f 3.22 2000 m 4.32 2000 f 4.53 3000 m 3.21 3000 f 3.44 4000 m 4.11 4000 f 3.99 I want to plot two lines (with symbols) for the two groups "m" and "f". I have tried the following: plot(xBar[gender=="m"]~freq[gender=="f"]) followed by

Greets, My data looks like: > p3.18 s xbar subgroup 1 0.84 12.2 1 2 1.64 11.2 2 3 2.07 10.6 3 4 2.49 12.2 4 5 0.84 11.2 5 ... Using the command > qcc(p3.18$xbar,type="xbar",sizes=5,center=mean(p3.18$xbar),std.dev=mean(p3.18$s)/0.94,title="X-bar Chart for Paper Sheet Length Data") I get the x-bar chart I expect. However,

Has anyone written utilities to do rescaled range analysis in R? Jeff -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch

Hi Gents, I need to get the control limits from qcc function. As follows: qcc(MDI, type = "xbar.one") Call: qcc(data = MDI, type = "xbar.one") xbar.one chart for MDI Summary of group statistics: Min. 1st Qu. Median Mean 3rd Qu. Max. 0.3266 0.4249 0.4371 0.4333 0.4451 0.4858 Group sample size: 1 Number of groups: 383 Center

Dear Rusers, I would like to color different sections of a histogram different colors. I have an example that was done by "brute force" given below. Has anyone implemented something like this in general? If not, any suggestions/pointers on how to write a general function to do so would be most appreciated. Alan-

Dear R users, I am stuck trying to figure out how to make a function return one value and print another.? Here is an example function: ################## eg <- function(x, digits=4) { xbar <- mean(x) sdx <- sd(x) value <- list(xbar, sdx) names(value) <- c("Mean of X", "SD of X") return(value)} ################## My current "solution" has been to

Hello R-users, I've been looking for a function performing one and two sample Hotelling test for testing equality of mean vectors. Has anyone implemented such a function in R? thanks a lot, Bill ============== Bill Donner Statistician

Muchísimas gracias Carlos, de verdad que te agradezco la ayuda, pero no es lo que voy buscando. Quiero colocar en el eje de abscisas la secuencia temporal de los meses, es decir, agosto septiembre, octubre, etc? pero no las fechas de las toma de datos, sino que aparezca la marca de un mes, y la siguiente marca sea la del siguiente mes, etc?, y además que las muestras estén separadas de acuerdo con

How do u calculated p values for a z test.. so far i ve done this A = read.table("cw3_data.txt") xbar = mean(A) s = 1 n = 20 mu = 0 z.test = (xbar-mu)/(s/sqrt(n)) p.value = pnorm(abs(z.test)) error = qnorm(0.99)*s/sqrt(n) left = xbar - error right = xbar + error and have got values off of it...but the values for p dont match up with other sites that i have used to check it

Hi, I wanted to understand exactly how acf and pacf works, so I tried to calculate ac and pac manually. For ac, I used the standard acf formula: acf(k) = sum(X(t)-Xbar)(X(t-k)-Xbar))/sum(X(t)-Xbar)^2. But for pac, I could not figure out how to calculate it by hand. I understand that in both R and EVIEWS, it is done using the Durbin-Levinson algorithm by the computer. However, I don't

Hi I am beginner with R I would like to compare the performance of Maximum likelihood Estimator (MLE) and Method of Moment Estimator (MME) effect probability of rejection, p. My MLE is x=rlnorm(10,meanlog = 2, sdlog =5) x xbar=mean(x) ssqrt=var(x) xbar ssqrt #MLE y=log(x) m1=mean(y) s1=var(y) m1 s1 #MME m2=log(xbar^2/sqrt(ssqrt+xbar^2)) s2 = log((ssqrt+xbar^2)/xbar^2) m2

Muchas gracias Carlos, previo a mi correo, entre las pruebas que hice estaba una parecida a la que apuntas de la siguiente manera: attach (Libro1) plot (xbar~as.Date(fechas,"%d/%m/%y"), ylim=c(400,660), xaxt="n", type="b", pch=19,cex=1) xlabels<-strptime(fecha,format="%d/%m/%Y") axis.Date (1,at=xlabels,format="%b-%y")

Hello, I have output that I want to print out. I am having a few issues. 1] output u to power is really nothing more than a 2 x 11 set of values formed using cbind function and printed out as a data frame How can I get it to output over several lines such as seen here? 2] Critical Z etc. were added by hand. I need an example of how I can mix alphanumeric and numeric data on