Displaying 20 results from an estimated 4000 matches similar to: "Fwd: r-stats: Geometric Distribution"
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
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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2000 May 12
1
Geometric Distribution at prob=c(0,1)
Dear all,
I''m working with the geometric distribution for the time being, and I''m
confused. This may have more to do with statistics than R itself, but
since I''m getting results from R I find counterintuitive (well, yeah, my
statistical intuition has not been properly sharpened), I feel like
asking.
The point first:
If I do
> rgeom(1,prob=1)
I get:
[1] NaN
Warning
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
2024 Jan 22
2
Use of geometric mean .. in good data analysis
>>>>> Rich Shepard
>>>>> on Mon, 22 Jan 2024 07:45:31 -0800 (PST) writes:
> A statistical question, not specific to R. I'm asking for
> a pointer for a source of definitive descriptions of what
> types of data are best summarized by the arithmetic,
> geometric, and harmonic means.
In spite of off-topic:
I think it is a good
2012 Jun 28
1
An extreme quantile of the geometric distribution
Hi,
With R version 2.10.0 (2009-10-26) on Windows, I computed the p=1.e-20
quantile of the geometric distribution with parameter prob=0.1.
> qgeom(1.e-20,0.1)
[1] -1
But this is not possible, since X=0,1,2,...
I guess that this might be a bug in the quantile function, which should
use the log1p function, instead of the naive formula.
Am I correct ?
Best regards,
Micha?l
2024 Jan 22
3
Use of geometric mean for geochemical concentrations
A statistical question, not specific to R.
I'm asking for a pointer for a source of definitive descriptions of what
types of data are best summarized by the arithmetic, geometric, and harmonic
means.
As an aquatic ecologist I see regulators apply the geometric mean to
geochemical concentrations rather than using the arithmetic mean. I want to
know whether the geometric mean of a set of
2024 Jan 30
2
Use of geometric mean for geochemical concentrations
Dear Rich,
It depends how the data is generated.
Although I am not an expert in ecology, I can explain it based on a biomedical example.
Certain variables are generated geometrically (exponentially), e.g. MIC or Titer.
MIC = Minimum Inhibitory Concentration for bacterial resistance
Titer = dilution which still has an effect, e.g. serially diluting blood samples;
Obviously, diluting the
2010 Nov 10
2
Performing a geometric seqeunce using iterators?
I want to make a function for geometric seqeunce
since
testing=function(x){i=1;ans=1;while(true){ans=ans+(1/x)^i ; i=i+1}
;return(ans)}
doesn't work... the program is freeze... from my research, i know i should
use iterators.
I read iterators.pdf at
http://cran.r-project.org/web/packages/iterators/iterators.pdf and didnt
find it helps solving my problem at all...
Is there any sources I
2024 Jan 24
1
Use of geometric mean for geochemical concentrations [RESOLVED]
On Mon, 22 Jan 2024, Rich Shepard wrote:
> As an aquatic ecologist I see regulators apply the geometric mean to
> geochemical concentrations rather than using the arithmetic mean. I want to
> know whether the geometric mean of a set of chemical concentrations (e.g.,
> in mg/L) is an appropriate representation of the expected value. If not, I
> want to explain this to non-technical
2009 Apr 03
2
Geometric Brownian Motion Process with Jumps
Hi,
I have been using maxLik to do some MLE of Geometric Brownian Motion Process and everything has been going fine, but know I have tried to do it with jumps. I have create a vector of jumps and then added this into my log-likelihood equation, know I am getting a message:
NA in the initial gradient
My codes is hear
#
n<-length(combinedlr)
j<-c(1,2,3,4,5,6,7,8,9,10)
2009 Aug 20
2
Geometric mean of rows in matrix
Is there a function or an easier way to computer geometric means of each
rows in a nxn matrix and spit out in an 1xn matrix ?
--
Edward Chen
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2011 Jan 17
1
median by geometric mean -- are we missing what's important?
Folks:
I know this may be overreaching, but are we missing what's important?
WHY do the zeros occur? Are they values less then a known or unknown
LOD? -- and/or is there positive mass on zero? In either case, using
logs to calculate a geometric mean may not make sense. Paraphrasing
Greg Snow, what is the scientific question? What is the model?
Cheers,
Bert
On Mon, Jan 17, 2011 at 9:13 AM,
2010 May 23
4
creating a reverse geometric sequence
Hello,
Can anyone think of a non-iterative way to generate a decreasing geometric
sequence in R?
For example, for a hypothetical function dg, I would like:
> dg(20)
[1] 20 10 5 2 1
where I am using integer division by 2 to get each subsequent value in the
sequence.
There is of course:
dg <- function(x) {
res <- integer()
while(x >= 1) {
res <- c(res, x)
x
2011 Jan 15
2
median by geometric mean
Hi All,
I need to calculate the median for even number of data points.However
instead of calculating
the arithmetic mean of the two middle values,I need to calculate their
geometric mean.
Though I can code this in R, possibly in a few lines, but wondering if there
is
already some built in function.
Can somebody give a hint?
Thanks in advance
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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
2011 Apr 06
1
Xen page sharing
Hi sahil:
I think the reason why you cannot get page shared is due to the gref you got.
Gref is responsible for a page allocated from domU, in my understanding it should not be
0, that is a gref 0 can not be shared, that''s why I skip gref 0 to be nominated.
The gref is nominated to Xen and later used to find a corrspond MFN, so it shall not always be the same.
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
1998 Nov 13
1
compute geometric mean
Hi:
I need to compute the geometric mean of a population. How i can do it??
thanks.
Jorge M. A. Magalhae
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