Displaying 20 results from an estimated 3000 matches similar to: "moments, skewness, kurtosis"
2004 Mar 31
3
Maximum number of connections in R
It appears that the maximum number of connections available
in R is about 48. Can anyone tell me how to bump this number
up? I've been perusing the source, but any info would speed
things up.
Is there a reason that it was set to such a low number?
Thanks for any help.
-Frank
2004 Aug 19
3
More precision problems in testing with Intel compilers
The Intel compiled version also fails the below test:
> ###------------ Very big and very small
> umach <- unlist(.Machine)[paste("double.x", c("min","max"), sep='')]
> xmin <- umach[1]
> xmax <- umach[2]
> tx <- unique(outer(-1:1,c(.1,1e-3,1e-7)))# 7 values (out of 9)
> tx <- unique(sort(c(outer(umach,1+tx))))# 11 values
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]
2005 Dec 01
2
about comparison of KURTOSIS in package: moments and fBasics
Hello
I do not know very much about statistics (and English language too :-( ),
then I come in search of a clarification (explanation):
I found two distinct results on KURTOSIS and
I do not know which of them is the correct one.
Any aid will be welcome!
klebyn
################ CODE
rnorm(1000) -> x
library(moments)
kurtosis(x)
skewness(x)
detach("package:moments")
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.
--
2004 Sep 13
3
.Random.seed in R-devel
I'm running R-2.0.0 (yesterday's snapshot)in its own
directory, and everything
works great, except:
> .Random.seed
Error: Object ".Random.seed" not found
Does 2.0.0 not use .Random.seed for saving, etc,
like it says in the help page?
Thanks for any help.
-Frank
2005 May 23
3
skewness and kurtosis in e1071 correct?
I wonder whether the functions for skewness and kurtosis in the e1071
package are based on correct formulas.
The functions in the package e1071 are:
# --------------------------------------------
skewness <- function (x, na.rm = FALSE)
{
if (na.rm)
x <- x[!is.na(x)]
sum((x - mean(x))^3)/(length(x) * sd(x)^3)
}
# --------------------------------------------
and
#
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)))
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
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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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
==========================
2004 Feb 11
1
how much memory? was: R does in memory analysis only?
Is there a way to tell how much memory the computer
running R has?
-Frank
-----Original Message-----
From: David Smith [mailto:dsmith at insightful.com]
Sent: Monday, February 09, 2004 1:32 PM
To: Ross Boylan
Cc: r-help
Subject: RE: [R] R does in memory analysis only?
Ross Boylan writes:
> R works only on problems that fit into (real or virtual) memory.
> ... does S-Plus have the same
2011 Aug 06
1
significance of differences in skew and kurtosis between two groups
Dear R-users,
I am comparing differences in variance, skew, and kurtosis between two groups.
For variance the comparison is easy: just
var.test(group1, group2)
I am using agostino.test() for skew, and anscombe.test() for kurtosis. However, I can't find an equivalent of the F.test or Mood.test for comparing kurtosis or skewness between two samples.
Would the test just be a 1 df test on
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
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 <-
2005 Jan 28
3
avoiding loops
Hi again,
thanks a lot for the quick answer. I just forgot the comma, always
these stupid mistakes...
Anyways, as I said before, I have two data.frames containing about 1000
rows and I would like to avoid looping through all of them...
In each data.frame are coordinates (x,y,z), so every row is giving the
information on one single point.
I would like to calculate the distance from each point
2009 Dec 23
2
Mean, median and other moments
Hi!
Suppose I have a dataset as follows
pd = c(10,7,10,11,7,11,7,6,8,3,12,7,7,10,10)
I wish to calculate the mean, standard deviation, median, skewness and kurtosis i.e. regular standard statistical measures.
average = mean(pd)
stdev = sd(pd)
median = median(pd)
skew = skewness(pd)
kurt = kurtosis(pd)
Q. No (1)
How do I get these at a stretch using some R package? I came across
2009 Dec 01
2
Calculation of Central Moments
Dear R helpers
If for a given data, I need to calculate Mean, Standard Deviation, Mode, Median, Skewness, Kurtosis, is there any package in R, which will calculate these moments?
Individually I can calculate these, but if there is any function which will calculate these at a stretch, please let me know.
Maithili
The INTERNET now has a personality. YOURS! See your Yahoo! Homepage.
2012 Jan 11
1
Confidence Interval from Moments?
Hi all,
I'm wondering whether it is possible to construct a confidence interval
using only the mean, variance, skewness and kurtosis, i.e. without any of
the population?
If anyone could help with this it'd be much appreciated (even if just a
confirmation of it being impossible!).
Thanks.
--
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2001 Oct 03
0
Summary : Generate random data from dist. with 0 skewness and some kurtosis
Thanks to all who response my problem. Here are my summary :
1. from Dirk Eddelbuettel <edd at debian.org>
We could try a mixture of normals -- ie flip a coin (use a uniform with
some cutoff c where 0 < c < 1 ) to choose between N(0, sigma_1) and N(0,
sigma_2).
2. from Michaell Taylor <michaell.taylor at reis.com>
We could use the gld library to specify the lambdas of