Displaying 20 results from an estimated 800 matches similar to: "How to draw several plots in one figure?"
2008 Jul 26
4
parametric bootstrap
Hi
I am trying to find a parametric bootstrap confidence interval and when I used the boot function I get zero bias and zero st.error? What could be my mistake?
Thank you and take care.
Laila
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2008 Jun 27
3
For loop
Hi,
Could you please let me know to use a list in a for loop here geneset is a
loop.I am trying to match the names of the list with 1st row of the output.
result<- list()
for(i in 1:length(output)
{
result[[i]] <- geneset(which(geneset %n% output[,1]))
}
Kindly help me out
--
View this message in context: http://www.nabble.com/For-loop-tp18163665p18163665.html
Sent from the R
2023 Aug 20
2
Issues when trying to fit a nonlinear regression model
Dear Bert,
Thank you so much for your kind and valuable feedback. I tried finding the
starting values using the approach you mentioned, then did the following to
fit the nonlinear regression model:
nlregmod2 <- nls(y ~ theta1 - theta2*exp(-theta3*x),
start =
list(theta1 = 0.37,
theta2 = exp(-1.8),
theta3 =
2023 Aug 20
3
Issues when trying to fit a nonlinear regression model
Dear friends,
This is the dataset I am currently working with:
>dput(mod14data2_random)
structure(list(index = c(14L, 27L, 37L, 33L, 34L, 16L, 7L, 1L,
39L, 36L, 40L, 19L, 28L, 38L, 32L), y = c(0.44, 0.4, 0.4, 0.4,
0.4, 0.43, 0.46, 0.49, 0.41, 0.41, 0.38, 0.42, 0.41, 0.4, 0.4
), x = c(16, 24, 32, 30, 30, 16, 12, 8, 36, 32, 36, 20, 26, 34,
28)), row.names = c(NA, -15L), class =
2008 Nov 26
1
Finding Stopping time
Can any one help me to solve problem in my code? I am actually trying to
find the stopping index N.
So first I generate random numbers from normals. There is no problem in
finding the first stopping index.
Now I want to find the second stopping index using obeservation starting
from the one after the first stopping index.
E.g. If my first stopping index was 5. I want to set 6th observation from
2004 May 15
2
questions about optim
Hi,
I am trying to do parameter estimation with optim, but I can't get it to
work quite right-- I have an equation X = Y where X is a gaussian, Y is a
multinomial distribution, and I am trying to estimate the probabilities of
Y( the mean and sd of X are known ), Theta1, Theta2, Theta3, and Theta4; I
do not know how I can specify the constraint that Theta1 + Theta2 + Theta3 +
Theta4 = 1 in
2008 Apr 22
4
how to convert non numeric data into numeric?
I am having the following error in my function
function(theta,reqdIRR)
{
theta1<-theta[1]
theta2<-theta[2]
n<-length(reqdIRR)
constant<- n*(theta1+theta2)
sum1<-lapply(reqdIRR*exp(theta1),FUN = sum)
sum2<-lapply(exp(theta2 - reqdIRR*exp(theta1)),FUN = sum)
sum = sum1 + sum2
log.fcn = constant - as.numeric(sum)
result = - log.fcn
return(result)
}
*error :
2023 Aug 20
1
Issues when trying to fit a nonlinear regression model
Oh, sorry; I changed signs in the model, fitting
theta0 + theta1*exp(theta2*x)
So for theta0 - theta1*exp(-theta2*x) use theta1= -.exp(-1.8) and theta2 =
+.055 as starting values.
-- Bert
On Sun, Aug 20, 2023 at 11:50?AM Paul Bernal <paulbernal07 at gmail.com> wrote:
> Dear Bert,
>
> Thank you so much for your kind and valuable feedback. I tried finding the
> starting
2023 Aug 20
1
Issues when trying to fit a nonlinear regression model
Dear Bert,
Thank you for your extremely valuable feedback. Now, I just want to
understand why the signs for those starting values, given the following:
> #Fiting intermediate model to get starting values
> intermediatemod <- lm(log(y - .37) ~ x, data=mod14data2_random)
> summary(intermediatemod)
Call:
lm(formula = log(y - 0.37) ~ x, data = mod14data2_random)
Residuals:
Min
2009 Nov 02
1
need help in using Hessian matrix
Hi
I need to find the Hessian matrix for a complicated function from a certain
kind of data but i keep getting this error
Error in f1 - f2 : non-numeric argument to binary operator
the data is given by
U<-runif(n)
Us<-sort(U)
tau1<- 2
F1tau<- pgamma((tau1/theta1),shape,1)
N1<-sum(Us<F1tau)
X1<- Us[1:N1]
2023 Aug 20
1
Issues when trying to fit a nonlinear regression model
Basic algebra and exponentials/logs. I leave those details to you or
another HelpeR.
-- Bert
On Sun, Aug 20, 2023 at 12:17?PM Paul Bernal <paulbernal07 at gmail.com> wrote:
> Dear Bert,
>
> Thank you for your extremely valuable feedback. Now, I just want to
> understand why the signs for those starting values, given the following:
> > #Fiting intermediate model to get
2023 Aug 20
1
Issues when trying to fit a nonlinear regression model
I got starting values as follows:
Noting that the minimum data value is .38, I fit the linear model log(y -
.37) ~ x to get intercept = -1.8 and slope = -.055. So I used .37,
exp(-1.8) and -.055 as the starting values for theta0, theta1, and theta2
in the nonlinear model. This converged without problems.
Cheers,
Bert
On Sun, Aug 20, 2023 at 10:15?AM Paul Bernal <paulbernal07 at
2008 Apr 22
2
optimization setup
Hi, here comes my problem, say I have the following functions (example case)
#------------------------------------------------------------
function1 <- function (x, theta)
{a <- theta[1] ( 1 - exp(-theta[2]) ) * theta[3] )
b <- x * theta[1] / theta[3]^2
return( list( a = a, b = b )) }
#-----------------------------------------------------------
function2<-function (x, theta)
{P
2007 Jul 26
3
substituting dots in the names of the columns (sub, gsub, regexpr)
Dear R users,
I have the following two problems, related to the function sub, grep,
regexpr and similia.
The header of the file(s) I have to import is like this.
c("y (m)", "BD (g/cm3)", "PR (Mpa)", "Ks (m/s)", "SP g./g.", "P
(m3/m3)", "theta1 (g/g)", "theta2 (g/g)", "AWC (g/g)")
To get rid of spaces and
2011 May 23
6
Reading Data from mle into excel?
Hi there,
I ran the following code:
vols=read.csv(file="C:/Documents and Settings/Hugh/My Documents/PhD/Swaption
vols.csv"
, header=TRUE, sep=",")
X<-ts(vols[,2])
#X
dcOU<-function(x,t,x0,theta,log=FALSE){
Ex<-theta[1]/theta[2]+(x0-theta[1]/theta[2])*exp(-theta[2]*t)
Vx<-theta[3]^2*(1-exp(-2*theta[2]*t))/(2*theta[2])
dnorm(x,mean=Ex,sd=sqrt(Vx),log=log)
}
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
2007 Sep 12
1
enquiry
Dear R-help,
I am trying to estimate a Cox model with nested effects basing on the
minimization of the overall AIC; I have two frailties terms, both gamma
distributed. There is a error message (theta2 argument misses) and I
don?t understand why. I would like to know what I have wrong. Thank you
very much for your time.
fitM7 <- coxph(Surv(lifespan,censured) ~ south + frailty(id,
2011 Jul 09
3
Confusing piece of R code
m0<-epxression((4*theta1*theta2-theta3^2)/(2*x*theta3^2)-0.5*theta1*x)
params<-all.vars(m0) this reads all the params
from m0 so theta1,2 and 3 correct?
params<-params[-which(params=="x")] checks which params are multiplied
by x?
np<-length(params)
for(i in 1:6){
esp<-get(sprintf("m%d",i-1))
2018 Feb 13
3
Help with regular expressions
R 3.4.2
OS X
Colleagues
I would appreciate some help with regular expressions.
I have string that looks like:
" ITERATION ,THETA1 ,THETA2 ,THETA3 ,THETA4 ,THETA5 ,THETA6 ,THETA7 ,SIGMA(1,1) ,SIGMA(2,1) ,SIGMA(2,2)?
In the entries that
2003 Feb 22
2
4-parameter logistic model
Dear R users
I'm a new user of R and I have a basic question about the 4-parameter
logistic model. According to the information from Pinheiro & Bates the model
is:
y(x)=theta1+(theta2-theta1)/(1+exp((theta3-x)/theta4)) ==
y(x)=A+(B-A)/(1+exp((xmid-input)/scal))
from the graph in page 518 of the book of the same authors (mixed models in
S) theta 1 corresponds to the horizontal asymptote