Displaying 20 results from an estimated 20000 matches similar to: "initial values for alpha and beta in Gamma inverse"
2011 Jan 13
1
Fitting an Inverse Gamma Distribution
http://r.789695.n4.nabble.com/file/n3216865/Inverse_Gamma.png
Hello,
I am seeking help in estimating the parameters of an inverse gamma
distribution (from the 'actuar' package) using a function like 'fitdistr'.
Unfortunately I haven't found such a package using findFn('fit Inverse
Gamma') from the 'sos' package and was therefore hoping someone might be
aware
2007 Jun 16
1
GLM dist Gamma-links identity and inverse
Dear users;
I am doing GLMs with the Gamma distribution, and I always get errors ("no valid set of coefficients: please supply starting values") or warnings ("NaNs produced in log(x)") when I use the links identity or inverse, but I don´t get them if I use the log link.
For example:
>
2010 Jun 03
3
(no subject)
Dear R users,
I am trying to draw error bars in a bar plot, I use this code (tried many others which did not work):
install.packages()
library(gplots)
y <-c(39.02, 46.42)
se <- c(7.57,7.35)
plot <- barplot(y, beside=TRUE, col=0, ylim=c(0,47), axis.lty=1, main="far-red", xlab="latitude", names.arg=c("56N", "68N"))
superpose.eb(plot, y, se,
2007 May 18
1
Inverse gamma
Hi, All:
assume I need to generate X from inverse gamma with parameter (k, beta).
should I generate from Y from gamma(-k, beta),
then take X=1/Y?
Thanks
pat
2012 Oct 04
2
Help with R Fitting an inverse Gamma
Dear all,
I am new in R and would like to ask for someone's help in understanding
where I go wrong with the following code:
rm(list=ls())
# Required packages
library(MCMCpack)
# Simulated data
set.seed(1)
data = rinvgamma(n=250, shape = 5, scale = 2) + 2
hist(data)
# log-likelihood
ll = function(par){
if(par[1]>0 & par[2]>0 & par[3]<min(data)) return(
2008 Dec 09
1
glm error message when using family Gamma(link="inverse")
R 2.5
windows XP
I am getting an error from glm() that I don't understand. Any help or suggestions would be appreciated. N.B. 1<=AAMTCAREJ<=327900
> summary(data$AAMTCAREJ)
Min. 1st Qu. Median Mean 3rd Qu. Max.
1.0 404.3 1430.0 6567.0 5457.0 327900.0
> fitglm<-glm(AAMTCAREJ~sexcat+H_AGE+SmokeCat+InsuranceCat+MedicadeCat+
+
2011 Feb 21
2
linear regression and t-distribution
Hello
I have a data set with outlier and it is not normally distributed. I would instead like to use a more robust distribution like t-distribution.
My question is if the coefficients of the regression are different from zero, but assuming a t-distribution.
Could someone hint me what package to use or....
Thanks in advance
Rosario
2010 Oct 27
2
plot by cathegories within a factor
Hello
I have a data set summarized like this:
File name= Height
Group Ind Age Trait
1 1 1 20
1 1 2 21
1 2 1 22
1 2 2 21
1 3 1 24
1 3 2 45
1 4 1 23
1 4 2 26
2 1 1 45
2 1 2 12
2 2 1 25
2 2 2 26
2 3 1 45
2 3 2 43
2 4 1 23
2 4 2 47
.
.
.
I would like to plot Trait ~ Age but a different plot for each Group.
I tried:
> plot(Height$Trait ~ Height$Age | Group)
But does not work. Any
2010 Nov 29
1
extracting P values from lm model
Hello
I am trying to get out of an lm model the fstatistics, however after I run the model I write
> names(Model)
and the fstatistic does not appear only these.
names(Model)
[1] "coefficients" "residuals" "effects" "rank" "fitted.values"
[6] "assign" "qr" "df.residual"
2011 Apr 04
1
multiple variables Y and X
Hello
I have a model with several hundred Y variables, and also several 1000 X variables. The model is linear lm(Y ~ X). My questions are:
1.- how to avoid writing all Xs variables? is list() the right function?
2.- about the multiple Ys with dependence among some of them, how to incorporate that information in the linear model?
Thank you
Rosario
2011 Jun 16
1
R in MAC add many extra <´s
Hello
I have a annoying problem with R (which I am running in MAC).
Every time I enter a function and I press enter to run it, I get many additional "<?s", it is really bothering me. I have tried to google to find out how to fix the problem but I did not succeed. Anyone with similar experience that could help me to change the set ups of the program or something.
Thanks in advance
2011 Jun 22
1
Factor Analysis with orthogonal and oblique rotation
Hello
I seem to find only two types of rotation for the factanal function in R, the Varimax and Promax, but is it possible to run a orthogonal and oblique rotations in R?
Thanks in advance
Rosario
2009 Dec 11
2
Regularized gamma function/ incomplete gamma function
Dear all,
I would be very grateful if you could help me with:
Given the regularized gamma function Reg=int_0^r (x^(k-1)e^(-x))dx/int_0^Inf (x^(k-1)e^(-x))dx ; 0<r<Inf (which is eventually the ratio of the
Incomplete gamma function by the gamma function), does anyone know of a package in R that would evaluate the derivative of the inverse of Reg with respect to k? I am aware that the
2011 Aug 04
3
persp()
Hello
I am trying to draw a basic black and white map of two European countries.
After searching some key words in google and reading many pages I arrived to the conclusion that persp() could be used to draw that map.
I have prepared three small example files, which are supposed to be the files required for running that function.
xvector is a vector with the longitudes
yvector is a vector with
2009 Dec 11
3
how can generate from trunceted gamma distribution in R ?
Hi, all
How can generate a sample from truncated inverse gamma distribution in R?
thanks
2011 Jul 31
3
export/import matrix
Hello
I have a problem on keeping the format when I export a matrix file with the write.table() function.
When I import the data volcano from rgl package it looks like this in R:
> data[1:5,]
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11] [,12] [,13] [,14]
[1,] 100 100 101 101 101 101 101 100 100 100 101 101 102 102
[2,] 101 101 102 102 102 102 102
2011 Jan 07
0
Fitting an Inverse Gamma Distribution to Survey Data
Hello,
I've been attempting to fit the data below with an inverse gamma
distribution. The reason for this is outside proprietary software (@Risk)
kicked back a Pearson5 (inverse gamma) as the best fitting distribution with
a Chi-Sqr goodness-of-fit roughly 40% better than with a log-normal fit.
Looking up "Inverse gamma" on this forum led me the following post:
2012 Feb 07
2
box.cox
Hello
I am using box.cox() and I get this error message:
Warning message:
'box.cox' is deprecated.
Use 'bcPower' instead.
See help("Deprecated") and help("car-deprecated").
I went to help but I did not understand the explanation, I am still wondering what is really happening.
Thanks
/R
2008 Sep 15
2
help on sampling from the truncated normal/gamma distribution on the far end (probability is very low)
Hi, guys,
I am trying to sample from a truncated normal/gamma distribution.
But only the far end of the distribution (where the probability is very low)
is left. e.g.
mu = - 4;
sigma = 0.1;
The distribution is Normal(mu,sigma^2) truncated on [0,+Inf];
How can I get a sample? I tried to use inverse CDF method, but got Inf as
answers. Please help me out.
Also, pls help me on the similar
2009 Dec 07
0
inverse gamma truncated
Hi, all
How can generate a sample from truncated inverse gamma distribution in R?
thanks