Displaying 20 results from an estimated 2000 matches similar to: "dpois().......bizarre warning messages"
2006 Jun 30
2
Query : Chi Square goodness of fit test
I want to calculate chi square test of goodness of fit to test,
Sample coming from Poisson distribution.
please copy this script in R & run the script
The R script is as follows
########################## start
#########################################
No_of_Frouds<-
c(4,1,6,9,9,10,2,4,8,2,3,0,1,2,3,1,3,4,5,4,4,4,9,5,4,3,11,8,12,3,10,0,7)
N <- length(No_of_Frouds)
# Estimation of
2015 Nov 03
1
Fwd: Rcpp sugar dpois
Hi. Here is a piece of cpp code.
It works, but I do not understand the rational for the use of
"R::dpois" to call the function dpois since in the examples I have always
found directly "dpois" or "Rcpp::dpois" that both do not work in my code.
Could anyone be so patient to explain me why should it be like that?
Thaks a lot, Enrico
#include <Rcpp.h>
using
2018 May 31
3
Understanding the sequence of events when calling the R dpois function
Hello all,
I am trying to get a better understanding of the underlying code for the stats::dpois function in R and, specifically, what happens under the hood when it is called. I finally managed to track down the C course at: https://github.com/wch/r-source/blob/trunk/src/nmath/dpois.c. It would seem that the dpois C function is taking a double for each of the x and lambda arguments so I am a bit
2009 Oct 27
1
Poisson dpois value is too small for double precision thus corrupts loglikelihood
Hi - I have a likelihood function that involves sums of two possions:
L = a*dpois(Xi,theta1)*dpois(Yi,theta2)+b*(1-c)*a*dpois(Xi,theta1+theta3)*dpois(Yi,theta2)
where a,b,c,theta1,theta2,theta3 are parameters to be estimated.
(Xi,Yi) are observations. However, Xi and Yi are usually big (>
20000). This causes dpois to returns 0 depending on values of theta1,
theta2 and theta3.
My first
2000 Feb 25
1
lambda==0 in dpois() (PR#459)
The nice new log=TRUE option in dpois appears to mess up the
case where lambda=0 (I was trying to calculate the likelihood
of a saturated model). Because the behavior is now always to
calculate the probability in terms of exp(log(prob)), there's
a test for lambda<=0 which really needs to be only lambda<0.
dpois(0:5,0)
ought to give
1 0 0 0 0
but gives NaNs instead.
Here's
2018 Jun 01
1
Understanding the sequence of events when calling the R dpois function
Chuck and Greg,
Thanks a lot for your help! I have a much better understanding now of what is happening ?under the hood?.
Kind Regards,
Jason
> On 31 May 2018, at 20:08, Greg Minshall <minshall at acm.org> wrote:
>
> Jason,
>
> as Chuck Berry (to whom, *thanks* for 'do {...} while(0)'!) suggested,
> using grep, or even grep executed from find, such as
>
2005 Nov 02
5
Distribution fitting problem
I am using the MASS library function
fitdistr(x, dpois, list(lambda=2))
but I get
Error in optim(start, mylogfn, x = x, hessian = TRUE, ...) :
Function cannot be evaluated at initial parameters
In addition: There were 50 or more warnings (use warnings() to see the first
50)
and all the first 50 warnings say
1: non-integer x = 1.452222
etc
Can anyone tell me what I am doing
2016 Apr 20
1
Use multiple cores on Linux
I am trying to run the following code in R on a Linux cluster. I would like
to use the full processing power (specifying cores/nodes/memory). The code
essentially runs predictions based on a GAM regression and saves the
results as a CSV file for multiple sets of data (here I only show two).
Is it possible to run this code using HPC packages such as
Rmpi/snow/doParallel? Thank you!
2009 Sep 19
1
Poisson Regression - Query
Hi All,
My dependent variable is a ratio that takes a value of 0 (zero) for 95% of
the observations and positive non-integer values for the other 5%. What
model would be appropriate? I'm thinking of fitting a GLM with a Poisson ~.
Now, becuase it takes non-integer values, using the glm function with
Poisson family issues warning messages.
Warning messages:
1: In dpois(y, mu, log = TRUE) :
2001 Aug 01
1
glm() with non-integer responses
A question about the inner workings of glm() and dpois():
Suppose I call
glm(y ~ x, family=poisson, weights = w)
where y contains NON-INTEGER (but still nonnegative) values.
(a) Does glm() still correctly maximise
the weighted Poisson loglikelihood ?
(i.e. the function given by the same formal expression as the
weighted loglikelihood of independent Poisson variables Y_i
except that the
1999 Apr 09
7
Error in ppois function (PR#161)
Full_Name: Murray H Smith
Version: 0.63.3
OS: Windows NT
Submission from: (NULL) (130.216.5.57)
The ppois function is displaced by -0.5.
Try:
> ppois(-0.5,1)
[1] 0.3678794
> ppois(-0.51,1)
[1] 0
> ppois(0,1)
[1] 0.3678794
and
> par(mfrow=c(2,1))
> x<-seq(-1,5,0.01)
> plot(x,ppois(x,1),type="s",ylab="F(x)",main="Poisson CDF?")
>
2005 Jul 20
2
Issues with convolve
We obtained some disturbing results from convolve() (inaccuracies and negative
probabilities). We'll try to make the context clear in as few lines as
possible...
Our function panjer() (code below) basically computes recursively the
probability mass function of a compound Poisson distribution. When the
Poisson parameter lambda is very large, the starting value of the recursive
scheme ---
2011 Nov 15
5
Convert back to lower triangular matrix
Given a vector;> ab = seq(0.5,1, by=0.1)> ab[1] 0.5 0.6 0.7 0.8 0.9 1.0
The euclidean distance between the vector elements is given by the lower triangular matrix > dd1 = dist(ab,"euclidean")> dd1 1 2 3 4 52 0.1 3 0.2 0.1 4 0.3 0.2 0.1 5 0.4 0.3 0.2 0.1 6 0.5 0.4 0.3 0.2 0.1
Convert the lower triangular matrix to a full
2011 Nov 15
1
Convert full matrix back to lower triangular matrix
Given a vector;> ab = seq(0.5,1, by=0.1)> ab[1] 0.5 0.6 0.7 0.8 0.9 1.0
The euclidean distance between the vector elements is given by the lower triangular matrix > dd1 =
dist(ab,"euclidean")> dd1 1 2 3 4 52 0.1 3 0.2 0.1 4 0.3 0.2 0.1 5 0.4 0.3 0.2 0.1 6 0.5 0.4 0.3 0.2 0.1
Convert the lower triangular matrix to a full
2005 Mar 04
1
Kerberos Tickets gone after reboot
Has anyone had experience with MIT Kerberos tickets not valid after server
reboot?
After server reboot I have to do a 'kinit' to get a new ticket, re-join the
AD domain, and restart samba. Then all is fine until I have to reboot the
server again.. Same thing again and again.
My time is synced, Kerberos tickets are good for 500d.
2004 Mar 02
2
Problem with Integrate
The background: I'm trying to fit a Poisson-lognormal distrbutuion to
some data. This is a way of modelling species abundances:
N ~ Pois(lam)
log(lam) ~ N(mu, sigma2)
The number of individuals are Poisson distributed with an abundance
drawn from a log-normal distrbution.
To fit this to data, I need to integrate out lam. In principle, I can
do it this way:
PLN1 <- function(lam, Count,
2008 Nov 14
2
GAM and Poisson distribution
Hi -I'm running a GAM with 7 explanatory variables with a Poisson error
structure. All of the variables are continuous so I'm getting error
messages in R.
cod.fall.full.gam.model<-gam(Kept.CPUE~s(HOUR)+s(LAT_dec)+s(LONG_dec)+s(meantemp_C)+s(meandepth_fa)+s(change_depth)+s(seds),
data=cod.fall.version2,family=poisson)
In dpois(y, mu, log = TRUE) ... : non-integer x = 5.325517
2011 Apr 27
3
Kolmogorov-Smirnov test
Hi,
I have a problem with Kolmogorov-Smirnov test fit. I try fit distribution to
my data. Actualy I create two test:
- # First Kolmogorov-Smirnov Tests fit
- # Second Kolmogorov-Smirnov Tests fit
see below. This two test return difrent result and i don't know which is
properly. Which result is properly? The first test return lower D = 0.0234
and lower p-value = 0.00304. The lower 'D'
2008 Dec 17
1
Asterisk 1.4 to AS5400 using H.323 (ooh323) inbound working but outbound doesn't
I have the following setup: DS3 -> Cisco AS5400 -> H.323 (ooh323) ->
Asterisk
Inbound calls work great but outbound calls fail. So to check and
make sure we have outbound calling ability on the DS3 we setup a Cisco
Call Manager Express and it can make outbound calls both local and
long distance with no problems.
The failure code is Cause i = 0x8381 - Unallocated/unassigned number.
We
2008 Jul 04
1
update on dnbinom with large "size"
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
~ turns out I don't need to look at the C code.
~ if one uses the mu/size parameterization of the
negative binomial, R computes size/(size+mu) to
switch parameterizations. If size>>mu this
gets rounded to 1 ... should be easy enough
to test and return NA under these circumstances?
function (x, size, prob, mu, log = FALSE)
{
~ if