Displaying 20 results from an estimated 3000 matches similar to: "Use of geometric mean .. in good data analysis"
2007 Jun 11
1
Gini coefficient in R
If I use the Ineq library and the Gini function in this way:
>Gini(c(100,0,0,0))
I obtain the result 0.75 instead of 1 (that is the perfect inequality).
I think Gini's formula in Ineq is based on a formula as reported here:
http://mathworld.wolfram.com/GiniCoefficient.html
but in the case of perfect inequality:
x_1=.......=x_n-1 =0
x_n>0
these formula are equal to 1 - 1/n, not to
2024 Jan 26
0
Use of geometric mean .. in good data analysis
Sorry to prolong a thread on something that is clearly off topic, but when Michael Meyer wrote
>by using the geometric mean all asymptotic results no longer apply.
that is flat our wrong. It's true that the geometric mean converges to something different that E[X], but it does indeed have an asymptotic distribution and one that makes sense in some contexts. There is no reason that
2019 Jun 24
1
Calculation of e^{z^2/2} for a normal deviate z
>>>>> jing hua zhao
>>>>> on Mon, 24 Jun 2019 08:51:43 +0000 writes:
> Hi All,
> Thanks for all your comments which allows me to appreciate more of these in Python and R.
> I just came across the matrixStats package,
> ## EXAMPLE #1
> lx <- c(1000.01, 1000.02)
> y0 <- log(sum(exp(lx)))
> print(y0) ## Inf
2016 Nov 14
0
Major update of package actuar
Dear useRs,
I'm happy to announce a substantial update of package actuar that bumps the version number to 2.0-0. This release focuses on additional support for continuous and discrete distributions, new functions to simulate data from compound models and mixtures, and revised and improved documentation.
A slightly shortened version of the NEWS file follows:
NEW FEATURES
? Support for the
2016 Nov 14
0
Major update of package actuar
Dear useRs,
I'm happy to announce a substantial update of package actuar that bumps the version number to 2.0-0. This release focuses on additional support for continuous and discrete distributions, new functions to simulate data from compound models and mixtures, and revised and improved documentation.
A slightly shortened version of the NEWS file follows:
NEW FEATURES
? Support for the
2004 Mar 16
3
multiple summation
Hello,
I have to compute a multiple summation (not an integration because the
independent variables a
are discrete) for all the values of a function of several variables f
(x_1,...,x_n), that is
sum ... sum f(x_1,...,x_n)
x_1 x_n
have you some suggestion? Is it possible?
I know that for multiple integration there is the function adapt, but it has at
most n=20. In my case n depends on the
2019 May 16
3
nrow(rbind(character(), character())) returns 2 (as documented but very unintuitive, IMHO)
Hi Hadley,
Thanks for the counterpoint. Response below.
On Thu, May 16, 2019 at 1:59 PM Hadley Wickham <h.wickham at gmail.com> wrote:
> The existing behaviour seems inutitive to me. I would consider these
> invariants for n vector x_i's each with size m:
>
> * nrow(rbind(x_1, x_2, ..., x_n)) equals n
>
Personally, no I wouldn't. I would consider m==0 a degenerate
2019 May 16
0
nrow(rbind(character(), character())) returns 2 (as documented but very unintuitive, IMHO)
The existing behaviour seems inutitive to me. I would consider these
invariants for n vector x_i's each with size m:
* nrow(rbind(x_1, x_2, ..., x_n)) equals n
* ncol(rbind(x_1, x_2, ..., x_n)) equals m
Additionally, wouldn't you expect rbind(x_1[i], x_2[i]) to equal
rbind(x_1, x_2)[, i, drop = FALSE] ?
Hadley
On Thu, May 16, 2019 at 3:26 PM Gabriel Becker <gabembecker at
2024 Jul 10
1
Implementation for selecting lag of a lag window spectral estimator using generalized cross validation (using deviance)
Dear All,
I am looking for:
A software to select the lag length for a lag window spectral estimator.
Also, I have a small query in the reprex given below.
Background for the above, from the book by Percival and Walden:
1. We are given X_1,...,X_n which is one realization of a stochastic process.
2. We may compute the periodogram using FFT, for example by the
function spectrum in R.
3. The
2010 Nov 03
1
Orthogonalization with different inner products
Suppose one wanted to consider random variables X_1,...X_n and from each subtract off the piece which is correlated with the previous variables in the list. i.e. make new variables Z_i so that Z_1=X_1 and Z_i=X_i-cov(X_i,Z_1)Z_1/var(Z_1)-...- cov(X_i,Z__{i-1})Z__{i-1}/var(Z_{i-1}) I have code to do this but I keep getting a "non-conformable array" error in the line with the covariance.
2008 Nov 01
2
sampling from Laplace-Normal
Hi,
I have to draw samples from an asymmetric-Laplace-Normal distribution:
f(u|y, x, beta, phi, sigma, tau) \propto exp( - sum( ( abs(lo) +
(2*tau-1)*lo )/(2*sigma) ) - 0.5/phi*u^2), where lo = (y - x*beta) and
y=(y_1, ..., y_n), x=(x_1, ..., x_n)
-- sorry for this huge formula --
A WinBUGS Gibbs sampler and the HI package arms sampler were used with the
same initial data for all parameters. I
2013 Mar 11
3
How to obtain the original indices of elements after sorting
Dear All,
Suppose I have a vector X = (x_1, x_2, ...., x_n), X_sort = sort(X)
= (x_(1), x_(2), ... , x(n) ),
and I would like to know the original position of these ordered x_(i)
in X, how can I do it?
case 1: all values are unique
x <- c( 3, 5, 4, 6)
x.sort <- sort(x) #
# I would like to obtain a vector (1, 3, 2, 4) which indicates that 3
in x is still the 1st element in x.sort, 5 is at
2006 Jan 06
1
vectorization of groups of dot products
I have a set of n vectors, x_1, ..., x_n, of the same length.
I would like to form the vector of dot products -- x_1'x_1, ..., x_n'x_n
the fastest way I can think to do this is to put the vectors into a
matrix
and do
diag(crossprod(X))
however, this seems to be very wasteful since this computes n(n+1)/2-n
unnecessary
dot products.
Is there a better way using existing functions in R?
2014 Nov 13
1
metafor - code for analysing geometric means
?Dear All
I have some data expressed in geometric means and 95% confidence intervals. Can I code them in metafor as:
rma(m1i=geometric mean 1, m2i=geometric mean 2, sd1i=geometric mean 1 CI /3.92, sd2i=geometric mean 2 CI/3.92.......etc, measure="MD")
All of the studies use geometric means.
Thanks!
Edward
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2001 Nov 29
1
errors in help("TDist")?
Dear all,
The help page on the t distribution says:
The most used applications are power calculations for t-tests:
Let T= (mX - m0) / (S/sqrt(n)) where mX is the `mean' and S the
sample standard deviation (`sd') of X_1,X_2,...,X_n which are
i.i.d. N(mu,sigma^2). Then T is distributed as non-centrally t
with `df'= n-1 degrees of freedom and non-centrality
2011 Nov 16
0
Maximum likelihood for censored geometric distribution
Hi all,
I need to check for a difference between treatment groups in the
parameter of the geometric distribution, but with a cut-off (i.e. right
censored). In my experiment I stimulated animals to see whether I got a
response, and stopped stimulating if the animal responded OR if I had
stimulated 10 times. Since the response could only be to a stimulation,
the distribution of response times
2023 Oct 17
2
Fwd: r-stats: Geometric Distribution
---------- Forwarded message ---------
From: Sahil Sharma <sahilsharmahimalaya at gmail.com>
Date: Tue, Oct 17, 2023 at 12:10?PM
Subject: r-stats: Geometric Distribution
To: <do-use-Contact-address at r-project.org>
Hey I want to raise one issue in *r-stats **geometric distribution *
function.
I have found the dgeom(x,p) which denotes probability density function of
geometric
2012 May 02
0
Robust estimation of a geometric random variable
Hi,
I have a bunch of data which is assumed to be instances of a geometric random variable with outliers. How can I do a robust estimation of the parameter p so that the effect of outliers is minimized?
As a part of the estimation process, I also need to know which are the outliers in the data. I found glmrob which does robust estimation of Poisson and binomial random variables but not geometric
2008 Feb 28
0
New Package: geozoo. High-Dimensional Geometric Objects
Dear useRs,
I'd like to announce a new package called geozoo, short for geometric
zoo. It's a compilation of functions to produce high-dimensional
geometric objects, including hypercubes and hyperspheres, Boy's
surface, the hyper torus and a selection of polytopes. For a complete
list, as well as images and movies, visit
2005 Jan 04
1
quantiles for geometric distribution
Dear list,
I have got an array with observational values t and I would like to fit
a geometric distribution to it.
As I understand the geometric distribution, there is only one
parameter, the probability p. I estimated it by 1/mean(t).
Now I plotted the estimated density function by
plot(ecdf(t),do.points=FALSE,col.h="blue");
and I would like to add the geometric distribution. This