Displaying 20 results from an estimated 5000 matches similar to: "Sample mean in R"
2011 Sep 02
5
Hessian Matrix Issue
Dear All,
I am running a simulation to obtain coverage probability of Wald type
confidence intervals for my parameter d in a function of two parameters
(mu,d).
I am optimizing it using "optim" method "L-BFGS-B" to obtain MLE. As, I
want to invert the Hessian matrix to get Standard errors of the two
parameter estimates. However, my Hessian matrix at times becomes
2008 Jun 25
0
Goodness-of-fit for zero-truncated poisson distribution
Hi there,
I am trying to write a function to perform GOF test of data to a
zero-truncated Poisson distribution. I am facing 2 problems.
1) How can I obtain a frequency table for all values within the range of
observed values?
For instance if the observations are
obs <- c("A", "A", "A", "A", "B", "C", "C", "D",
2005 Apr 05
2
Stats Question: Single data item versus Sample from Norma l Distribution
Here's one possibility, assuming muhat and sigmahat are estimtes of mu and
sigma from N iid draws of N(mu, sigma^2):
tStat <- abs(x - muhat) / sigmahat
pValue <- pt(tStat, df=N, lower=TRUE)
I'm not quite sure what df tStat should have (exercise for math stat), but
given fairly large N, that should make little difference.
Andy
> From: Ross Clement
>
> Hi. I have a
2007 Jan 26
1
plotting results from tapply
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)
2003 Jul 22
4
greek in main title
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
2007 Jul 25
3
Constructing bar charts with standard error bars
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
2020 Oct 10
3
Please need help to finalize my code
Good evening dear administrators,
It is with pleasure that I am writing to you to ask for help to finalize my
R programming algorithm.
Indeed, I attach this note to my code which deals with a case of
independence test statistic . My request is to introduce the kernels using
the functional data for this same code that I am sending you. So I list the
lines for which we need to introduce the
2013 Feb 08
2
qcc package
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,
2007 Dec 30
1
Histogram with different colors for different portions
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-
2011 Mar 03
3
Probabilities greather than 1 in HIST
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",
2008 Sep 02
2
qcc help
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
2006 Nov 05
3
struggling to plot subgroups
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
2020 Oct 13
1
Please need help to finalize my code
Hm. Google tells me that kernel function is in stats package which comes with base installation and is invoked when you start R.
search()
[1] ".GlobalEnv" "package:stats" "package:graphics"
[4] "package:grDevices" "package:utils" "package:datasets"
[7] "package:methods" "Autoloads"
2020 Oct 13
0
Please need help to finalize my code
What do you *mean* "when you want to use the kernels".
WHICH kernels?
Use to do WHAT?
In your browser, visit cran.r-project.org
then select "Packages" from the list on the left.
Then pick the alphabetic list.
Now search for 'kernel'.
You will find dozens of matches.
On Wed, 14 Oct 2020 at 05:15, PIKAL Petr <petr.pikal at precheza.cz> wrote:
> Hm. Google tells
2017 Jul 08
2
CRAN I-MR / Xbar-R / Xbar-S control chart package ?
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
2020 Oct 09
1
Aide pour finaliser ce code
Hello.
Here is my R code. I used the functional data . Now I need to use the
functional data by applying the kernels instead of the xi, yi functions.
Bonjour.
Voici mon code en R . J'ai utiliser les donn?es fonctionnelles . Maintenant
j'ai besoin d'utiliser les donn?es fonctionnelles en appliquant les noyaux
? la place des fontions xi, yi
library(MASS)
2007 Apr 28
1
pacf
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
2010 Mar 12
2
Return one value, print another
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
2010 May 05
4
P values
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
2002 May 11
2
Bug on Mac version of lm()?
Dear Mac users,
Hi, as you might have probably read the thread of
"[R] Rsquared in summary(lm)" on May 10, it seems that Mac version of
lm() seem to be working incorrectly.
I enclose the script to produce the result both for lm() and manual
calculation for a simple regression. Could you run the script and
report with the version of R, so I don't have to go through every
builds