Displaying 20 results from an estimated 11000 matches similar to: "Random Forest for multiple categorical variables"
2012 Oct 22
1
random forest
Hi all,
Can some one tell me the difference between the following two formulas?
1. epiG.rf <-randomForest(gamma~.,data=data, na.action = na.fail,ntree =
300,xtest = NULL, ytest = NULL,replace = T, proximity =F)
2.epiG.rf <-randomForest(gamma~.,data=data, na.action = na.fail,ntree =
300,xtest = NULL, ytest = NULL,replace = T, proximity =F)
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2004 Apr 21
2
Question on CAR appendix on NLS
The PDF file on the web, which is an appendix on nonlinear regression
associated with the CAR book, is very nice.
When I ran through the code presented there, I found something
odd. The code does a certain model in 3 ways: Vanilla NLS (using
numerical differentation), Analytical derivatives (where the user
supplies the derivatives) and analytical derivatives (using automatic
differentiation). The
2013 Apr 03
3
Generating a bivariate joint t distribution in R
Hi,
I conduct a panel data estimation and obtain estimators for two of the
coefficients beta1 and beta2. R tells me the mean and covariance of the
distribution of (beta1, beta2). Now I would like to find the distribution
of the quotient beta1/beta2, and one way to do it is to simulate via the
joint distribution (beta1, beta2), where both beta1 and beta2 follow t
distribution.
How could we
2008 Dec 03
1
hypergeometric
Hi,
I hope somebody can help me on how to use the hypergeometric function.
I did read through the R documentation on hypergeometric but not really
sure what it means.
I would like to evaluate the hypergeometric function as follows:
F((2*alpha+1)/2, (2*alpha+2)/2 , alpha+1/2, betasq/etasq).
I'm not sure which function should be used- either phyper or qhyper or
dhyper
Where
2012 Oct 23
1
Minimizing Computational Time
Dear R-users,
May I seek some suggestions from you. I have a long programme written in R
with several 'for' loops inside. I just want to get them out by any elegant
way (if there is!) to reduce the computational time of the main programme.
For instance, is there any smart way for the following programme that will
lessen time?
2013 Mar 11
2
vertical lines in R plot
Dear All,
May I seek your suggestion on a simple issue. I want to draw vertical lines
at some positions in the following R plot. To be more specific, I wish to
draw vertical lines at d=c(5.0,5.5,6) and they should go till
p=c(0.12,0.60,0.20) . I haven't found any way out, though made several
attempts. Please run the following commands first if you are interested in!
2009 Jul 12
2
Nonlinear Least Squares nls() programming help
Hi, I am trying to use the nls() function to closely approximate a vector of
values, colC and I'm running into trouble. I am not sure how if I am asking
the program to do what I think its doing, because the same minimization in
Excel's Solver does not run into problems. If anyone can tell me what is
going wrong, and why I'm getting a singular convergence(7) error, please
tell me. I
2006 Oct 17
4
if statement error
Hi List,
I was not able to make this work. I know it is a simple one, sorry to bother. Give me some hints pls. Thanks!
Jen
if(length(real.d)>=30 && length(real.b)>=30 && beta1*beta2*theta1*theta2>0 )
{ r <- 1; corr <- 1; }
real.d and real.b are two vectors, beta1,beta2,theta1,and theta2 are constants. The error occurred like this:
Error in if
2012 Dec 04
1
Winbugs from R
Hi,
I am trying to covert a Winbugs code into R code. Here is the winbugs code
model{# model’s likelihoodfor (i in 1:n){time[i] ~ dnorm( mu[i], tau ) # stochastic componenent# link and linear predictormu[i] <- beta0 + beta1 * cases[i] + beta2 * distance[i]}# prior distributionstau ~ dgamma( 0.01, 0.01 )beta0 ~ dnorm( 0.0, 1.0E-4)beta1 ~ dnorm( 0.0, 1.0E-4)beta2 ~ dnorm( 0.0, 1.0E-4)#
2018 Apr 04
1
parfm unable to fit models when hazard rate is small
Hello, I would like to use the parfm package: https://cran.r-project.org/web/packages/parfm/parfm.pdfhttps://cran.r-project.org/web/packages/parfm/parfm.pdf in my work. This package fits parametric frailty models to survival data. To ensure I was using it properly, I started by running some small simulations to generate some survival data (without any random effects), and analyse the data using
2009 Aug 25
1
Help with nls and error messages singular gradient
Hi All,
I'm trying to run nls on the data from the study by Marske (Biochemical
Oxygen Demand Interpretation Using Sum of Squares Surface. M.S. thesis,
University of Wisconsin, Madison, 1967) and was reported in Bates and Watts
(1988).
Data is as follows, (stored as mydata)
time bod
1 1 0.47
2 2 0.74
3 3 1.17
4 4 1.42
5 5 1.60
6 7 1.84
7 9 2.19
8 11 2.17
I then
2011 Nov 09
2
Error in drawing
I have got following error in drawing wavelet fitting. can some one help?
> library(faraway)
> data(lidar)
> newlidar<-lidar[c(1:128),]
> library(wavethresh)
> wds <- wd(newlidar$logratio)
> draw(wds)
Error in plot.default(x = x, y = zwr, main = main, sub = sub, xlab = xlab,
:
formal argument "type" matched by multiple actual arguments
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2011 Nov 29
3
Problem in log
Hi all I have a function of log defined by y = log(1- exp(-a)), when
exp(-a) is greater, 1, it produce NaN. How can I remove this in R?
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2004 Apr 16
5
Non-Linear Regression (Cobb-Douglas and C.E.S)
Dear all,
For estimating Cobb-Douglad production Function [ Y = ALPHA * (L^(BETA1)) *
(K^(BETA2)) ], i want to use nls function (without linearizing it). But
how can i get initial values?
------------------------------------
> options(prompt=" R> " )
R> Y <- c(59.6, 63.9, 73.5, 75.6, 77.3, 82.8, 83.6, 84.9, 90.3, 80.5,
73.5, 60.3, 58.2, 64.4, 75.4, 85, 92.7, 85.4,
2009 Jul 01
2
Difficulty in calculating MLE through NLM
Hi R-friends,
Attached is the SAS XPORT file that I have imported into R using following code
library(foreign)
mydata<-read.xport("C:\\ctf.xpt")
print(mydata)
I am trying to maximize logL in order to find Maximum Likelihood Estimate (MLE) of 5 parameters (alpha1, beta1, alpha2, beta2, p) using NLM function in R as follows.
# Defining Log likelihood - In the function it is noted as
2023 Aug 20
1
Determining Starting Values for Model Parameters in Nonlinear Regression
The cautions people have given about starting values are worth heeding. That nlxb() does well in many cases is useful,
but not foolproof. And John Fox has shown that the problem can be tackled very simply too.
Best, JN
On 2023-08-19 18:42, Paul Bernal wrote:
> Thank you so much Dr. Nash, I truly appreciate your kind and valuable contribution.
>
> Cheers,
> Paul
>
> El El
2006 Mar 27
1
Missing Argument in optim()
Hello everybody,
i already searched the archieves, but i still don't know what is wrong
in my implementation, mybe anybody coud give me some advice
ll1<-function(rho,theta,beta1,beta2,beta3,beta4,t,Szenariosw5,Testfaellew5,X1,X2)
{
n<-length(t)
t<-cumsum(t)
tn<-t[length(t)]
Szenn<-Szenariosw5[length(Szenariosw5)]
2009 Jan 18
1
My Problem
Hello, My name is Edwin, I come from INDONESIA
I have problem
I creating function then I have many calculation
like this
xx<-function(){
a<-sd(....)
b<-beta1.hat
c<-beta2.hat
data.entry(a,b,c)
}
then
i have function too, almost same
yy<-function(){
d<-sd(....)
e<-beta1.hat
f<-beta2.hat
data.entry(d,e,f)
}
I have 6 function almost same
then
my problem is
I can't
2010 Mar 26
1
Problems if optimization
What's up fellows...
I am a begginer in R and i am trying to find the parameters of one
likelihood function, but when i otimize it, always appers a error or
advertisement and the solve does not occur.
The problem seems like that:
"lMix<-function(pars,y){
beta1<-pars[1]
beta2<-pars[2]
beta3<-pars[3]
beta4<-pars[4]
beta5<-pars[5]
alfa1<-pars[6]
2005 Nov 09
5
How to find statistics like that.
Hi there,
Suppose mu is constant, and error is normally distributed with mean 0 and
fixed variance s. I need to find a statistics that:
Y_i = mu + beta1* I1_i beta2*I2_i + beta3*I1_i*I2_i + +error, where I_i is
1 Y_i is from group A, and 0 if Y_i is from group B.
It is large when beta1=beta2=0
It is small when beta1 and/or beta2 is not equal to 0
How can I find it by R? Thank you very much