similar to: what is wrong with this code?

Displaying 20 results from an estimated 4000 matches similar to: "what is wrong with this code?"

2009 May 15
4
displaying results
Hi everyone, can anyone tell me how i can change how i display mean(age), i want it to say The mean age of patients within the sample is mean(age) -- View this message in context: http://www.nabble.com/displaying-results-tp23558890p23558890.html Sent from the R help mailing list archive at Nabble.com.
2009 Aug 17
2
help with expression()
Hello. I have a vector and within that vector is one expression. When I display this vector it comes up as expression(NA_character_, NA_character_, "Null Effect", "Pooled effect", NA_character_, NA_character_, NA_character_, NA_character_, NA_character_, paste("Het Contours ", I^2, sep = ""), 0.4, 0.41, 0.42, 0.45, NA_character_) Where the
2012 Feb 09
1
Constraint on one of parameters.
Dear all, I have a function to optimize for a set of parameters and want to set a constraint on only one parameter. Here is my function. What I want to do is estimate the parameters of a bivariate normal distribution where the correlation has to be between -1 and 1. Would you please advise how to revise it? ex=function(s,prob,theta1,theta,xa,xb,xc,xd,t,delta) { expo1=
2009 Aug 17
2
Newbie that don't understand R code
I got some R code that I don't understand. Question as comment in code //where is t comming from, what is phi inverse rAC <- function(name, n, d, theta){ #generic function for Archimedean copula simulation illegalpar <- switch(name, clayton = (theta < 0), gumbel = (theta < 1), frank = (theta < 0), BB9 = ((theta[1] < 1) | (theta[2] < 0)), GIG = ((theta[2] < 0) |
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
2005 Mar 16
1
Code to replace nested for loops
Dear list members, How can I replace the nested for loops at then end of the script below with more efficient code? # Begin script__________________________________________________ # Dichotomous scores for 100 respondents on 3 items with # probabilities of a correct response = .6, .4, and .7, # respectively x1 <- rbinom(100,1,.6) x2 <- rbinom(100,1,.4) x3 <- rbinom(100,1,.7) #
2008 Mar 19
1
problem with optim and integrate
Dear all, I want to min "integrate( (p1*dnorm+p2*dnorm+p3*dnorm)^(1.3))" for p, mu, and sigma. So, I have to estimate 8 parameters(p3=1-p1-p2). I got this warning-"Error in integrate(numint, lower = -Inf, upper = Inf) : non-finite function value." My questions are How could I fix it? I tried to divide into several intervals and sum up, but I got same message. My code is
2006 Apr 19
1
Function to approximate complex integral
I am writing a small function to approximate an integral that cannot be evaluated in closed form. I am partially successful at this point and am experiencing one small, albeit important problem. Here is part of my function below. This is a psychometric problem for dichotomously scored test items where x is a vector of 1s or 0s denoting whether the respondent answered the item correctly (1) or
2009 Aug 17
2
unnecessary braces?
the version 2 parser thinks I have unnecessary braces, but I can't find any. False positive or am I missing something? If a false positive, is there any way to work around the warning? * checking Rd files against version 2 parser ... WARNING Warning: ./man/dbetabinom.Rd:32-34: Unnecessary braces at ?{p(x) = % (C(N,x)*Beta(N-x+theta*(1-p),x+theta*p))/% Beta(theta*(1-p),theta*p)}?
2008 Dec 27
1
indexed expression
Hello expeRts, I need generate symbolize the autocovariances matrix of a Gaussian ARMA(1,1), for derivate it and evaluate. I try this codes, but whitout sucess vacv<-NULL vacv[1]<-1-2*phi*theta-theta^2 vacv[2]<-(1-phi*theta)*(phi-theta) vacv[3:n]<-acv[2]*(phi^(1:(n-2))) facv<-list() for(i in 1:2)
2005 May 31
1
Solved: linear regression example using MLE using optim()
Thanks to Gabor for setting me right. My code is as follows. I found it useful for learning optim(), and you might find it similarly useful. I will be most grateful if you can guide me on how to do this better. Should one be using optim() or stats4::mle? set.seed(101) # For replicability # Setup problem X <- cbind(1, runif(100)) theta.true <- c(2,3,1) y <- X
2011 Aug 17
2
An example of very slow computation
This message is about a curious difference in timing between two ways of computing the same function. One uses expm, so is expected to be a bit slower, but "a bit" turned out to be a factor of >1000. The code is below. We would be grateful if anyone can point out any egregious bad practice in our code, or enlighten us on why one approach is so much slower than the other. The problem
2006 Jul 25
5
greek letters, text, and values in labels
Hello, I want to have a title that will look something like: "Results for \theta=2.1", given that I have a variable theta=2.1, and \theta should show on the screen like the greek letter. I've tried a lot of things: theta <- 2.1 plot(1:10, main=expression(paste("Results for", theta, "=", eval(theta)))) or using bquote plot(1:10, main=paste("Results for
2009 Nov 08
3
MCMC gradually slows down
Hello, I have written a simple Metropolis-Hastings MCMC algorithm for a binomial parameter: MHastings = function(n,p0,d){ theta = c() theta[1] = p0 t =1 while(t<=n){ phi = log(theta[t]/(1-theta[t])) phisim = phi + rnorm(1,0,d) thetasim = exp(phisim)/(1+exp(phisim)) r = (thetasim)^4*(1-thetasim)^8/(theta[t]^4*(1-theta[t])^8) if(runif(1,0,1)<r){ theta[t+1] = thetasim }
2014 Mar 03
1
reference classes, LAZY_DUPLICATE_OK, and external pointers
We (the lme4 authors) are having a problem with doing a proper deep copy of a reference class object in recent versions of R-devel with the LAZY_DUPLICATE_OK flag in src/main/bind.c enabled. Apologies in advance for any improper terminology. TL;DR Is there an elegant way to force non-lazy/deep copying in our case? Is anyone else using reference classes with a field that is an external pointer?
2012 Dec 04
1
Solve system of equations (nleqslv) only returns origin
I'm solving 4 complex equations simultaneously. Code is below. The code returns only zero's for the solution though there should also be a non-zero result. I'm pretty confident that the equations are correct because they are straight from a published paper and I checked them pretty thoroughly. The parameter values I used are from the published paper as well. Any suggestions for how
2006 Apr 05
2
R2WinBUGS error
Dear R-help, I'm using the R2WinBUGS package and getting an error message: Error in file(file, "r") : unable to open connection In addition: Warning message: cannot open file 'codaIndex.txt', reason 'No such file or directory' I'm using R 2.2.1 and WinBUGS 1.4.1 on a windows machine (XP). My R code and WinBUGS code is given below.
2009 Nov 02
2
a prolem with constrOptim
Hi, I apologize for the long message but the problem I encountered can't be stated in a few lines. I am having some problems with the function constrOptim. My goal is to maximize the likelihood of product of K multinomials, each with four catagories under linear constraints on the parameter values. I have found that the function does not work for many data configurations. #The likelihood
2006 Jul 20
2
Timing benefits of mapply() vs. for loop was: Wrap a loop inside a function
List: Thank you for the replies to my post yesterday. Gabor and Phil also gave useful replies on how to improve the function by relying on mapply rather than the explicit for loop. In general, I try and use the family of apply functions rather than the looping constructs such as for, while etc as a matter of practice. However, it seems the mapply function in this case is slower (in terms of CPU
2006 Sep 30
1
Gradient problem in nlm
Hello everyone! I am having some trouble supplying the gradient function to nlm in R for windows version 2.2.1. What follows are the R-code I use: fredcs39<-function(a1,b1,b2,x){return(a1+exp(b1+b2*x))} loglikcs39<-function(theta,len){ value<-sum(mcs39[1:len]*fredcs39(theta[1],theta[2],theta[3],c(8:(7+len))) - pcs39[1:len] * log(fredcs39(theta[1],theta[2],theta[3],c(8:(7+len)))))