similar to: Fast optimizer

Hi, I have a couple of aggregation operations that I don't know how to accomplish. Let me give an example. I have the following irregular time series time x 10:00:00.021 20 10:00:00.224 20 10:00:01.002 19 10:00:02:948 20 1) For each entry time, I'd like to get sum of x for the next 2 seconds

Hi, To set a simple an clear picture of what I'd like to do, here is an example. I would like to calculate mean of column A and B bucketed by factor in column X in a data.frame. lapply or aggregate operates on a single column. I found dapply function in some package which doesn't seem to exist any more. Is there anyway that I can accomplish something like this? Thank you so much in

Hi,R_Help! I have done something like this: >x<-seq(412,612,1) >plot(x,dpois(x,512),col="blue",type="l") >plot(x,dnorm(x,512,sd=sqrt(512)),col="red",type="l") And now,I want to plot the two lines in the same picture or with the same "plot" action? What should I do? And any advises? Thank you in advance! 仭仭仭仭仭仭仭仭仭仭仭仭仭仭仭仭伖併佇伹

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

Hi, I have the following string that I converted to a POSIXct: > a <- "2009-08-24 10:00:00.213" > a.p <- strptime(a,"%Y-%m-%d %H:%M:%OS") > as.double(as.POSIXct(a.p)) [1] 1251122400 I can't seem to get the decimal fraction of .213 out by casting to double or numeric. Is there anyway to make sure that POSIXct spits that out? Thank you. adschai

Hi - I read through dse package manual a bit. I'm not quite certain how I can use it to estimate a time varying coefficient regression model? I might pick up an inappropriate package. Any suggestion would be greatly appreciated. Thank you. rh

Hi, When I define a new class (through setClass), members defined in representation argument doesn't seem to like a class. For example, if I do the following: setClass("NotWork",representation=(x="zoo")) It seems to me that representation members will take in only primitive type to R. Is there any way to stuff a class as a member in another class? Thank you. - adschai

Hi, I am trying to install package xts. I am using OPENSUSE 11 64 bit. When I invoke: install.pacakges("xts",dependencies=T) I received a lot of "ERROR: compilation failed for package" errors when R tries to install xts dependencies. I do not understand this behavior. I notice one thing. It complains. ERROR: compilation failed for package 'Hmisc' ** Removing

Hi, I have a matrix or data.frame (df). When I would like to check if a column named "x" exists, it becomes my habit to do the following: if (length(which(colnames(df)=="x"))>0) Is there any smarter way to do this? Thank you. adschai [[alternative HTML version deleted]]

Hi, I have a list that contains about 100 elements. Each element contains the following matrix structure a b 1 1 4 2 2 5 3 3 6 I'd like to sum column b across all elements. I'm thinking of using lapply or sapply but cannot get it to work. Any help would be really appreciated. Thank you. adschai

Hi, I'm running into a wall when trying to use the integrate function. I have the following setting: powerLaw2 <- function(x,l1,l2,c0,t0) { idx <- which(x <= 0); if (length(idx) > 0) { x[idx] <- 0; } xl <- (-l1+l2)*log(x/t0); L <- log(c0)-l1*log(x)-log(1+exp(xl)); L <- exp(L); return(L); } plCDF2 <- function(x,l1,l2,c0,t0) {

Hi, I'm a bit puzzled. I uses exactly the same code in RcppExamples package to try adding RcppFrame object to RcppResultSet. When running it gives me segmentation fault problem. I'm using gcc 4.1.2 on redhat 64bit. I'm not sure if this is the cause of the problem. Any advice would be greatly appreciated. Thank you. Rob. int numCol=4; std::vector<std::string>

Hello: I wish to again express my appreciation to all who have contributed to making R what it is today. At this moment, I'm particularly grateful for whoever modified the 'mle' code so data no longer need be passed via global variables. I remember struggling with this a couple of years ago, and I only today discovered that it is no longer the case. I'd

Hi, How can we set the environment for the minuslog function in mle()? The call in this code fails because the "ll" function cannot find the object 'y'. Modifying from the example in ?mle: library(stats4) ll <- function(ymax=15, xhalf=6) { -sum(stats::dpois(y, lambda=ymax/(1+x/xhalf), log=TRUE)) } fit.mle <- function(FUN, x, y) { loglik.fun <- match.fun(FUN)

A few day ago, I was looking for an answer to my question but didn't get one. Anybody who can help now? Hello, I tried to use mle to fit a distribution(zero-inflated negbin for count data). My call is very simple: mle(ll) ll() takes the three parameters, I'd like to be estimated (size, mu and prob). But within the ll() function I have to judge if the current parameter-set gives a nice

With the exception of "L-BFGS-B", all of the other optim() methods return the value of the function when they are given a trivial function (i.e., one with no variable arguments) to optimize. I don't think this is a "bug" in L-BFGS-B (more like a response to an undefined condition), but it leads to a bug in stats4::mle -- a spurious error saying that a better fit has been

Hi there, I'm pretty new to the field of fitting (anything). I try to fit a distribution with mle, because my real data seems to follow a zero-inflated poisson distribution. So far, I tried a simple example to see whether I understand how to do it or not: # example count data x <- 0:10 y <- dpois(x, lambda = 1.4) # zero-inflated poisson zip <- function(x, lambda, prop) { (1 -

Hi everyone! I am using the mle {stats4} to estimate the parameters of distributions by MLE method. I have a problem with the examples they provided with the mle{stats4} html files. Please check the example and my question below! *Here is the mle html help file * http://stat.ethz.ch/R-manual/R-devel/library/stats4/html/mle.html http://stat.ethz.ch/R-manual/R-devel/library/stats4/html/mle.html

Hi I have the following formula (I hope it is clear - if no, I can try to do better the next time) h(x, a, b) = integral(0 to pi/2) ( ( integral(D/sin(alpha) to Inf) ( ( f(x, a, b) ) dx ) dalpha ) and I want to do an mle with it. I know how to use mle() and I also know about integrate(). My problem is to give the parameter values a and b to the

R 2.3.0 Linux, SuSE 10.0 Hi I have two problems with mle - probably I am using it the wrong way so please let me know. I want to fit different distributions to an observed count of seeds and in the next step use AIC or BIC to identify the best distribution. But when I run the script below (which is part of my original script), I get one error message for the first call of mle: Error in