Displaying 20 results from an estimated 200 matches similar to: "Problem with dgamma function."
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.
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 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
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).
2002 Jan 11
2
new dgamma rate argument
Can someone explain to me in what way the new (dpqr)gamma parameter
can be interpreted as a rate (when shape != 1)? The only gamma rate
that I am aware of is the hazard rate given by dgamma/(1-pgamma), the
log of which is returned by my hgamma function (event library).
Jim
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing list -- Read
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
2006 Jun 03
1
Fw: Compiling chan_bluetooth
Just to close the thread. The problem was that I was using an old version of
the code.
If anyone has the same problem, you can download the code from here:
http://www.thetechguide.com/howto/asterisk/bluetoothfiles.tar.gz
Good luck,
Danko
----- Original Message -----
From: "Danko Miocevic" <danko@santirso.com.ar>
To: "Asterisk
2006 May 08
4
Asterisk documentation..
Where can I get some asterisk books.. or tutorials..? I?ve been searching in
google.. but I find just some tutorials explaining how to fast set up an
asterisk server. I want to learn how to use it and how to make my own
configurations. So, the thing is that I want to know what is the best book
or tutorial that you know? recomendations? Thanks to everyone...
Danko Miocevic
2006 May 27
1
Compiling chan_bluetooth
Hello, I?m trying to use my phone with asterisk to get GSM connectivity but
I can?t compile the code.
I got the asterisk, chan_bluetooth, zaptel and libpri sources, the last two
ones compiled perfectly.
I have added this to the /usr/src/asterisk/channels/Makefile:
include /usr/src/chan_bluetooth/Makefile
and I?ve also added chan_bluetooth.so to the CHANNEL_LIBS var.
When I do "make
2007 Nov 16
4
Returning vectors of two different data types back to R environment (from C).
Hello,
Quick question.
I have written a C function - I would like to make it return two vectors to
the R environment - one STRSXP vector, and one INTSXP vector. Is this
possible/ easy to do using the API?
I looked, but could not find the answer to this question in the "Writing R
Extensions" guide.
Thanks very much for your help!
Charles
[[alternative HTML version deleted]]
2008 Mar 05
1
SEXP size management.
Hi,
Trying to decrease the size of a SEXP variable without reassigning
values individually in a loop.
So far, I've tried using Realloc, as the follow source demonstrates:
SEXP dothis() {
SEXP Rblah;
PROTECT(Rblah = NEW_INTEGER(6));
int* blah = INTEGER(Rblah);
blah[0] = 1;
blah[1] = 2;
blah[2] = 3;
Realloc(Rblah, 3, INTEGER);
UNPROTECT(1);
return(Rblah);
}
According to the
2008 Apr 23
1
cbind speed.
cbind/ rbind/ data.frame functions are very convenient for merging
vectors of different types into a single data frame, but take quite a
bit of time to execute on larger data sets.
Is it possible to speed these up a bit?
What functions do you use instead?
Thanks & regards,
Charles
2008 Oct 25
1
Dynamic linking to binary code from other packages??
Dear R-devel,
I am writing a package that needs some C++ functions from an external
SDK (Affymetrix fusion). The same functions are already compiled into
another package (affxparser).
Can I dynamically link to the compiled code in affxparser, rather than
re-compiling these separately into my package?
Not a lot of experience on this subject!
Thanks,
Charles
2013 Apr 09
5
Error when using fitdist function in R
Hello everyone,
I was trying to do some distribution fitting with a numerical field called
Tolls. The sample size = 999 rows.
Basically I assigned the Toll data to a new variable K by doing:
k<-dtest$Toll
After that, tried to fit a gamma distribution by doing: fitG<-fitdist(k,
"gamma")
Then the following messages showed (oh and I checked for empty rows before
doing this):
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
2000 Feb 10
3
creating a grid of function values
I want to create a grid of function values for use in `contour' or
`persp'. The function is the log-likelihood for the gamma. The
sample is stored as vector of length 20 called `Survival'.
A single evaluation of the log-likelihood at, say, scale = 9 and shape
= 10 would be obtained by
sum(dgamma(Survival, scale = 9, shape = 10, log = TRUE))
(This may work only 0.99.0, I'm not
2008 May 21
2
Converting Data Types
Hi,
How can I convert the matrices to list.
For example I have this snippet:
samples<-mymatrix[1,]
print(samples)
which prints:
V1 V2 V3 V4 V5 V6
1 103.9 88.5 242.9 206.6 175.7 164.4
How can I convert the object "samples" such that it prints:
[1] 103.9 88.5 242.9 206.6 175.7 164.4
The reason I ask this because I can't use the former
"samples"
2003 Sep 30
3
fitdistr, mle's and gamma distribution
Dear R Users,
I am trying to obtain a best-fit analytic distribution for a dataset
with 11535459 entries. The data range in value from 1 to 300000000. I
use: fitdistr(data, "gamma") to obtain mle's for the parameters.
I get the following error:
Error in optim(start, mylogfn, x = x, hessian = TRUE, ...) :
non-finite finite-difference value [1]
And the following warnings: