Displaying 20 results from an estimated 2000 matches similar to: "new dgamma rate argument"
2013 Jul 12
2
How to determine the pdf of a gamma distribution using the estimated parameters?
Hello everyone,
With th bar histogram (number of occurrences) hist<-c(24,7,4,1,2,1,1) of seven equally spaces classes ]1-4], ]5-8], ]9-12], ]13-16], ]17-20], ]21-24], ]25-28], I obtained shape=0.8276 and rate=0.1448.
I would like to know how to build the continuous pdf of a this gamma distribution knowing these two estimated parameters such that I will be able to predict the pdf of any
2001 Sep 06
1
RFC: d/p/q/rgamma
dgamma and friends in S are documented as
dgamma(x, shape, rate=1)
pgamma(q, shape, rate=1)
qgamma(p, shape, rate=1)
rgamma(n, shape, rate=1)
whereas R has
dgamma(x, shape, scale=1, log = FALSE)
pgamma(q, shape, scale=1, lower.tail = TRUE, log.p = FALSE)
qgamma(p, shape, scale=1, lower.tail = TRUE, log.p = FALSE)
rgamma(n, shape, scale=1)
Note the use of rate vs scale. Indeed, as both S and
2007 Oct 07
1
a function to compute the cumulative distribution function (cdf) of the gamma
Un texte encapsul? et encod? dans un jeu de caract?res inconnu a ?t? nettoy?...
Nom : non disponible
Url : https://stat.ethz.ch/pipermail/r-help/attachments/20071006/065906cc/attachment.pl
2005 Nov 09
2
help with legacy R code
Hi there,
Could somebody help me disect this legacy R script I inherited at work, I
have two questions:
1. I've tried to upgrade our R version from 1.6.2 (yeah, I know), to R 2.0,
but some of the lines in this script are not compatible with R 2.0, could
someone help me figure out where the problem is?
2. the jpeg generated (attached) seems to be off on some of the data, is
there a better way
2009 Sep 25
1
Problem with dgamma function.
Hi, All,
I am getting some funny results trying to use R's built in
distribution functions.
In R:
> dgamma(4.775972,1.37697964405418, 0.106516604930466)
[1] 0.05585295
> dgamma(4.775972,1.37697964405418, 0.106516604930466,TRUE) ### THIS IS JUST WRONG!
[1] 0.01710129
> log(dgamma(4.775972,1.37697964405418, 0.106516604930466))
[1] -2.885033
>
In C:
2007 Apr 23
2
Problem with dgamma ?
Hi All,
Here 's what I got using dgamma function :
> nu<-.2
> nu*log(nu)-log(gamma(nu))+(nu-1)*log(1)-nu*(1)
[1] -2.045951
> dgamma(1,nu,nu,1)
[1] 0.0801333
> dgamma(1,nu,nu,0)
[1] NaN
Warning message:
NaNs produced in: dgamma(x, shape, scale, log)
Could anyone tell me what is wrong here ?
I am using R-2.4.1 on windows XP.
Thanks a lot.
2011 Sep 10
1
dgamma in jags within r
I define priors in jags within r using a gamma distribution. I would
like to control the shape but I have problems. Any help will be usefull.
From help of dgamma
___________________
The Gamma distribution with parameters shape = a and scale = s has density
f(x)= 1/(s^a Gamma(a)) x^(a-1) e^-(x/s)
and rate=1/scale
From jags user manual
____________________
dgamma(r, mu) has a density of
2009 Apr 12
3
p-values from bootstrap - what am I not understanding?
Dear stats experts:
Me and my little brain must be missing something regarding bootstrapping. I
understand how to get a 95%CI and how to hypothesis test using bootstrapping
(e.g., reject or not the null). However, I'd also like to get a p-value from
it, and to me this seems simple, but it seems no-one does what I would like
to do to get a p-value, which suggests I'm not understanding
2016 Nov 13
1
dgamma density values in extreme point
Dear R-Devel group,
My name is Alexey, a data scientist from Moscow, currently working for
Align Technology Inc.
We have recently had a discussion of the results that the dgamma
function (stats) returns for an extreme point (x == 0).
<dgamma(0,1,1,log = FALSE)
[1] 1
and
<dgamma(0,0.5,1,log = FALSE)
[1] Inf
Density appears to be defined in point zero for the distribution with
the
2011 Sep 19
2
Poisson-Gamma computation (parameters and likelihood)
Good afternoon/morning readers. This is the first time I am trying to run
some Bayesian computation in R, and am experiencing a few problems.
I am working on a Poisson model for cancer rates which has a conjugate Gamma
prior.
1) The first question is precisely how I work out the parameters.
#Suppose I assign values to theta with *seq()*
*theta<-seq(0,1,len=500)*
#Then I try out the
2008 Jun 25
1
dgamma in WinBUGS and JAGS (rjags)
Hello,
In WinBUGS 1.4 manual
(http://www.mrc-bsu.cam.ac.uk/bugs/winbugs/manual14.pdf), the gamma
density is presented as dgamma(r,mu) where r and mu are the shape and
rate parameters, respectively. In JAGS (rjags) manual version 1.0.2,
May 9, 2008 (http://www-fis.iarc.fr/~martyn/software/jags/jags_user_manual.pdf),
on page 26 the gamma density is presented as dgamma(mu,r) instead of
dgamma(r,mu).
2001 Dec 17
1
behavior of r* and d* functions at boundaries (PR#1218)
(Sent this to r-help back in October, got no comments, forgot
to re-submit it as a bug report.)
There are a few inconsistencies, at least, in some of the functions that
generate random deviates from particular distributions (I think they're
bugs because they're inconvenient, but maybe someone can make an argument
for the current behavior). If people think these are really bugs I can
2008 Aug 21
1
pnmath compilation failure; dylib issue?
(1) ...need to speed up a monte-carlo sampling...any suggestions about
how I can get R to use all 8 cores of a mac pro would be most useful
and very appreciated...
(2) spent the last few hours trying to get pnmath to compile under os-
x 10.5.4...
using gcc version 4.2.1 (Apple Inc. build 5553) as downloaded from
CRAN, xcode 3.0...
...xcode 3.1 installed over top of above after
2004 Feb 05
5
rgamma question
I was trying to generate random numbers with a gamma distribution. In R the
function is:
rgamma(n, shape, rate = 1, scale = 1/rate). My question is that if
X~gamma(alpha, beta) and I want to generate one random number where do I
plug alpha and beta in rgamma? and, what is the meaning and use of rate?
Thanks for your attention,
Jorge
[[alternative HTML version deleted]]
2001 Nov 09
2
ks.test
Dear R-List members,
I want to check if a set of measurements follows better a
gamma or a lognormal distribution (see data below).
Using shapiro.test I can test for normality (shapiro.test(log
(Lt)).
To test for gamma (and normal) distribution I would use
ks.test but I need to specify its shape and scale. How should
I calculate these values in R?
I tried
> Lt.fit <- glm(Lt ~ 1,
1998 Feb 23
1
R-beta: Help: cov.mve in R? dgamma in Splus?
Hi all
I have a couple of obscure questions for R/Splus experts (which
unfortunately isn't me!)
I am trying to compute Bayes Factors using some Splus code of Raftery
in Gilks et al (1996). Only problem is
1) R doesn't seem to have a robust covariance (cov.mve) which I
suspect I need rather than a non-robust classical estimate
2) Splus has cov.mve BUT dgamma in Splus doesn't have a
2005 Nov 04
1
dgamma error condition?
There's an apparent inconsistency between the
behavior of d(pqr)gamma and other distribution
functions for "bad" parameter values. Specifically,
most distributions give NaN and a warning for bad
parameters (e.g. probabilities <0 or >1). In contrast,
d(pqr)gamma actually gives an error and stops when shape<0.
I don't see why it has to be this way -- the internal
C code
2005 Jun 25
1
comment in src/nmath/dgamma.c
Hi,
In src/nmath/dgamma.c the comment at the top says
* DESCRIPTION
*
* Computes the density of the gamma distribution,
*
* 1/s (x/s)^{a-1} exp(-x/s)
* p(x;a,s) = -----------------------
* (a-1)!
*
* where `s' is the scale (= 1/lambda in other parametrizations)
* and `a' is the shape parameter ( = alpha in
2012 Mar 13
1
Coding C++ in R. What is faster : Using bosst external libraries or R.h header file?
Hi everyone,
I have built an R package and for the sake of speed I have decided to rewrite some part of the code in C++. In my original R code I use the pnorm, qnorm, rnorm, pgamma, dgamma, rgamma, rbeta and runif function. First I was thinking in going with the boost libraries, but I noticed the functions described above are available within the R.h header file (or is it Rmath.h?).
So my
2011 Dec 07
1
data frame and cumulative sum
Hello,
I have a data frame that looks like this (containing interarrival times):
> str(df)
'data.frame': 18233 obs. of 1 variable:
$ Interarrival: int 135 806 117 4 14 1 9 104 169 0 ...
> head(df)
Interarrival
1 135
2 806
3 117
4 4
5 14
6 1
>
This corresponds to the time differences (in ms) of a poisson arrival