Displaying 20 results from an estimated 2000 matches similar to: "Mean, median and other moments"
2009 Dec 14
2
Combinations
Dear R helpers,
I am working on the scenario analysis pertaining to various interest rates. In this connection I need to form the various combinations as under :
Suppose I have two sets A = (a, b, c) and B = (x,y,z)
Then I can easily form the cominations as
(ax, ay, az, bx, by, bz, cx, cy, cz)
However, if I have say 5 variables, then total no of possible combinations will be 3^5 = 243.
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")
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]
2010 Feb 03
2
How to change output 'csv' file
Dear R helpers
After executing the R code, where the last few lines of the code are something like given below.
## Part of my R code
n = 20
........
.........
final_output = data.frame(Numbers = numbers, ABC = data1, XYZ = data2, PQR = data3)
write.csv(data.frame(Scenario = paste("Sc_", 1:n, sep = ""), final_output'), 'result.csv', row.names
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
2010 Feb 12
1
how to read csv file having variables unequal column sizes
Dear R helpers
Suppose e.g. I have a csv file having three variables defined and each of these variables have data items of say 40, 50, 45 length. When I open this csv file in 'R', I get 10 trailing 'NA's under first column and 5 'NA' s in case of 3rd column.
How do I get rid of these NA's s.t. when I read the first column, there should be only 40 data items, 2nd
2010 Feb 18
1
Matrix in a Reverse order
Dear 'R' friends
I have a sort of stupid question to ask.
I have a matrix say of the order 4 X 3 as
83 98 90
21 83 84
70 39 56
65 29 38
Is there any command in R which will reverse the order i.e. I need to have same 4 X 3 matrix but as given below
65 29 38
70 39 56
21 83 84
83 98 90
i.e. the last row becomes first row, second - last row
2009 Dec 04
3
Combinations and joint probabilities
Dear R helpers
Suppose I have two sets of ranges (interest rates) as
Range 1 : (7 – 7.50, 7.50 – 8.50, 8.50 – 10.00) with respective probabilities 0.42, 0.22 and 0.36.
Range II : (11-12, 12-14, 14-21) with respective probabilities 0.14, 0.56 and 0.30 respectively.
My problem is to form the combinations of these ranges in a decreasing order of joint probabilities. It is assumed that
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.
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
#
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.
--
View this message in context:
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.
--
2011 Mar 14
0
Fitting 4 moments distribution w/ Mixture Gaussian
Hello,
I know that Mclust does the fitting on its own but I am trying to implement
an optimization with the aim to generate a the mixture gaussian with the
combine moments as closed as possible to the moment of my return
distribution.
The objective is to Min Abs((Mean Ret - MeanFit)/Mean Fit) + Abs((Std Ret
-Stdev Fit)/Stdev) + Abs((Sk Ret-Sk fit)/Sk Fit) + Abs((Kurt Ret- Kurt Fit))
Taking
2010 Mar 03
1
help R IRT simulation
hello R,
This is about simulation in psychomtrics in IRT in R. I want to simulate b
parameters(item difficulty) with moments of fixed values of mean, st.d,
skewness and kurtosis. Is there any specific IRT package in R with those
functions to control those moments? I have seen other programs that can
control mean and st.d but not skewness and kurtosis.
Thank you,
helen L
[[alternative HTML
2004 Sep 21
2
Ever see a stata import problem like this?
Greetings Everybody:
I generated a 1.2MB dta file based on the general social survey with
Stata8 for linux. The file can be re-opened with Stata, but when I bring
it into R, it says all the values are missing for most of the variables.
This dataset is called "morgen.dta" and I dropped a copy online in case
you are interested
http://www.ku.edu/~pauljohn/R/morgen.dta
looks like this
2007 Feb 22
1
Diagnostic Tests: Jarque-Bera Test / RAMSEY
Hello R-Users,
The following questions are not R-technical, but more of general statistical
nature.
1. NORMALITY
I built a normal linear regression model and now I want to check for the
residual normality assumption. If I check the distribution graphically and
look at the descriptive characteristics (skewness and kurtosis are below 1),
I would confirm that the residuals are normally
2009 Mar 17
1
Need a little help setting the upper median using "layout"...
The code I'm using is shown below.
I would like to have a larger median at the top of the plot so that I can show the entirity of "title_text".
Several times I tried messing with "par(mar", but that seemed to make matters worse.
By any chance can anyone provide any insight as to the best way to increase the top/upper/northern margin, so the entirity of the title is
2008 Nov 06
4
mean computation for external data
I have an external data (.txt) for
annual peak flood. The first column is the year, second column is the
observation date, and the last is the observed discharge. My task is to
calculate the mean, skewness and kurtosis of the said data. I was advised to use
read.table() to read the entire data. Please help me on how to perform the
required computation. I am obviously a new user of this statistical
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
2020 Oct 15
2
package(moments) issue
Hi Bill,
Thanks for prompt reply and letting me know a way around it.
I have more than 1200 observations and not all the values are the same.
However, my data points are quite similar, for example,
0.079275, 0.078867, 0.070716 in millions and etc. I have run the data
without converting it to millions and I still get the same error
message. As I have kurtosis value, it should be fine for the