Displaying 20 results from an estimated 2000 matches similar to: "Estimation of skewness from quantiles of near-normal distribution"
2006 Jan 10
1
Find last row (observation) for each combination of variables
Let's say I have a data.frame like
A B C TS other columns
1 1 1 12345
1 1 1 56789
1 2 1 23456
1 2 2 23457
2 4 7 23458
2 4 7 34567
2 4 7 45678
and I want the last row for each unique combination of A/B/C, where by "last" I mean greatest TS.
A B C TS other columns
1 1 1 56789
1 2 1 23456
1 2 2 23457
2 4 7 45678
I did this simply in SAS:
proc sort data=DF;
by A B C descending TS
2006 Jan 10
1
"Missing value representation in Excel before
I reproduce from memory my exhaustive look into this issue.
RODBC uses the Microsoft ODBC DLL's developed by Microsoft.
These DLL's perform an automatic determination of column type based on the contents of the first N rows of cells in each column, where N [0,16]. N may be set in the Windows system registry, and there are a few other things that may be set in the system registry which
2005 Dec 23
1
how to specify dev.print target by a variable?
I want to do the following:
DEVw=500
DEVh=350
fname="my_plot"
dev.print(file=fname, device=FOO, width=DEVw, height=DEVh, bg="transparent")
How do I do this such that I can specify FOO to be one of several choices? (GDD, PNG, postscript, etc.)
If I make FOO a character variable, then "dev.print" complains.
I tried a simpled "substitute" but
2005 Sep 09
1
PowerPoint graph insertion
Yes: I have Tufte's monograph on my desk. (along with 4 statistics texts)
Yes: I am not the biggest fan of PowerPoint.
Yes: I am using R to generate charts, plots, trends, etc. I have to summarize them each week.
When I consider how to organize this data my first thought is to generate an HTML file with links to the R-generated plots, which HTML file organizes the plots in the required
2011 Mar 14
0
Non-constancy of variances in mixed model.
Hi, I've been doing an experiment, measuring the dead-zone-diameters of
bacteria, when they've been grown with paper diffusion disks of
antimicrobial. There are two groups, or treatments - one is bacteria
that have been cultured in said antimicrobial for the past year, the
other group is of the same species, but lab stock and has not gone had
any prior contact with the antimicrobial.
2005 Nov 29
2
qcc
violating.runs
I read from the news
cran.r-project.org/doc/Rnews/Rnews_2004-1.pdf
that the criteria for the violating is 5 but
1)I cannot find "5" in the code of the function. Where is the "5" ?
2)What is the easiest way to change it ?
3)Is there any more criterias made somewhere ?
Yours sincerelly, Tommi Viitanen
2006 Mar 02
0
Combining plaintext and plotmath expressions
I searched the archives and did not find a solution, so I pose this question to those well-versed in the use of plotmath and expressions.
I have a list of strings in an external CSV file which I wish to use sometimes as plot axis labels and sometimes as plot titles. These strings combine plaintext and a few mathematical expressions (Greek letters, subscripts). Moreover, I sometimes need to
2006 Mar 30
0
request to add "..." to cat(ngettext in "warnings" function
Madams & Sirs,
I am working on porting some R code to one of our servers to run under web or crontab direction. With that in mind I have been working on directing informative, warning, and error messages to outputs as I require. I would like to suggest a change to the "warnings" function; that the passed arguments be enabled to all instances of "cat" in the function,
2004 Aug 30
3
D'agostino test
Hi, Does anyone know if the D'agostino test is available with R ?
Alex
1999 Jul 28
1
skewness, kurtosis
Dear R-Users and Developpers,
Currently R does not include functions to compute the skewness and
kurtosis. I programmed it myself in the following way, but probably
*real* programmers/statisticians can do that better:
mykurtosis <- function(x) {
m4 <- mean((x-mean(x))^4)
kurt <- m4/(sd(x)^4)-3
kurt
}
myskewness <- function(x) {
m3 <- mean((x-mean(x))^3)
skew <-
2010 Jun 24
4
Simple qqplot question
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
1999 Aug 31
1
Suggestion for qqplot() improvement
>>>>> On Tue, 31 Aug 1999 14:57, Werner Stahel <stahel@stat.math.ethz.ch> said:
WSt> Here is a suggestion. It seems that qqplots, comparing a sample
WSt> to a distribution other than the normal, are not explicitly
WSt> available in S or R. I found
(in S-plus / Trellis it is, see below)
WSt> qqplot(y, rt(300, df = 5))
WSt> as an
2008 Sep 23
3
Generating series of distributions with the same skewness and different kurtosis or with same kurtosis and different skewness?
Dear R users,
I hope to explain the concepts of skewness and kurtosis by generating
series of distributions with same skewness and different kurtosis or with
same kurtosis and different skewness, but it seems that i cannot find the
right functions.
I have searched the mailing list, but no answers were found.
Is it possible to do that in R? Which function could be used?
Thanks a lot.
--
2006 Sep 08
1
Computing skewness and kurtosis with the moments package
Hi,
I'm a newcomer to R, having previously used SPSS. One problem I have
run into is computing kurtosis. A test dataset is here:
http://www.whinlatter.ukfsn.org/2401.dat
> library(moments)
> data <- read.table("2401.dat", header=T)
> attach(data)
> loglen <- log10(Length)
With SPSS, I get
Skewness -0.320
Kurtosis -1.138
With R:
> skewness(loglen)
[1]
2011 Oct 25
1
alternative option in skewness and kurtosis tests?
I have a question about the D'Agostino skewness test and the Anscombe-Glynn
kurtosis test.
agostino.test(x, alternative = c("two.sided", "less", "greater"))
anscombe.test(x, alternative = c("two.sided", "less", "greater"))
The option "alternative" in those two functions seems to be the null
hypothesis. In the output, the
2004 Feb 09
2
moments, skewness, kurtosis
I checked the help and the mailing list archives, but I can
find no mention of a routine that calculates higher
moments like skewness and kurtosis. Of course, these
are easy enough to write myself, but I was thinking
that they MUST be in here. Am I wrong?
Thanks.
-Frank
2004 Oct 27
2
Skewness and Kurtosis
Hi,
in which R-package I could find skewness and kurtosis
measures for a distribution?
I built some functions:
gamma1<-function(x)
{
m=mean(x)
n=length(x)
s=sqrt(var(x))
m3=sum((x-m)^3)/n
g1=m3/(s^3)
return(g1)
}
skewness<-function(x)
{
m=mean(x)
me=median(x)
s=sqrt(var(x))
sk=(m-me)/s
return(sk)
}
bowley<-function(x)
{
q<-as.vector(quantile(x,prob=c(.25,.50,.75)))
2003 Nov 08
1
notation for skewness and kurtosis
Hello everybody,
this is a bit off topic, so maybe you can just reply to me personally...
What is the typical notation for 'skewness', 'kurtosis' and maybe 'excess
kurtosis'?
Thank you,
Martina
--------------------------------------------------------------------------
Department of Statistics Office Phone: (614) 292-1567
1958 Neil Avenue, 304E Cockins Hall
2001 Sep 28
1
Generate rand. data with zero skewness and some kurtosis
Dear all,
Right now, I'm doing research about outlier in statistical data
(univariate and multivariate) and I want to simulate its behavior. My
problem is :
How to generate random data from distribution with zero skewness and
some kurtosis values in R ?
A. Kudus
=====================
Dept. of Statistics
Bandung Islamic University
I n d o n e s i a
==========================
2001 Dec 10
2
distributions w. skewness & kurtosis
Is there some reasonable way to generate random data from a
distribution that has some degree of skewness and/or kurtosis, but
would otherwise be normal?
thanks,
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