similar to: Fitting exponential curve to data points

Hope these help for alternatives to lm()? I show the use of a 2nd order polynomial as an example to generalize a bit. Sometimes from the subject line two separate responses can appear as reposts when in fact they are not... (though there are identical reposts too). I should probably figure a way around that. --- Stephen Tucker <brown_emu at yahoo.com> wrote: > ## Data input > input

Hello, I have what should be an easy question. I'm a new r user and making the transition from menus to the command line so as to do batch processing of tons of data. One of my data streams needs to be detrended. It's a vector of numbers that follows a negative exponential decay. I need to fit a curve to it and use the residuals as an object. The data looks something like this: foo.dat

Dear useRs, I have the following plot: pos <- c(27/44, 11/32, 8/40, 4/42, 3/40, 4/40, 2/40) tmin <- c(15.8, 12.6, 10.5, 2.4, 5.2, 8.5, 7.9) plot(tmin, pos) I would like to fit an exponential curve to it. How could I be able to do this? Thanks in advance, Rafael. ____________________________________________________________________________________ [[elided Yahoo spam]]

Hi all, I have a dataset which consists of 2 columns. I'd like to plot them on a x-y scatter plot and fit an exponential trendline. I'd like R to determine the equation for the trendline and display it on the graph. Since I am new to R (and statistics), any advice on how to achieve this will be greatly appreciated. Many thanks, Chris -- View this message in context:

Hi all, Like a lot of people I noticed that I get different results when I use nls in R compared to the exponential fit in excel. A bit annoying because often the R^2 is higher in excel but when I'm reading the different topics on this forum I kind of understand that using R is better than excel? (I don't really understand how the difference occurs, but I understand that there is a

I'm doing some string manipulation on a vector of file names, and noticed something curious. When I strsplit the vector, I get a list of character vectors. The list is numbered, as lists are. When I cast that list as a data frame with 'as.data.frame()', the resulting columns have names derived from the original filenames. Example code is below. My question is, where are these names

Hi, I'm trying to set up NFSv4 on two boxes (centos 5.5) and have it authenticate against our Windows 2008R2 AD server acting as the KDC. (samba/winbind is running ok with "idmap config MYCOMPANY: backend = rid" so we have identical ids across the servers.) I can mount my test directory fine via NFSv4 *without* the sec=krb5 option. However, once I put the sec=krb5 option in,

Hi, I would like to fit some experimental points by a exponential function. I ignore the parameters of this exponential and what I would like is to ask R to calculate the best fitting curve an the associated parameters (as the linear model function (lm) does for linear models). Is it possible ? Do anyone have an idea about how to do that ? Thanks by advance Jessica Gervais [[alternative

I recently came to realize the true power of R for statistical analysis -- mainly for post-processing of data from large-scale simulations -- and have been converting many of existing Python(SciPy) scripts to those based on R and/or Perl. In the middle of this conversion, I revisited the problem of curve fitting for simulation data with multiple observations resulting from repetitions. In the

Dear R-help, Here's a simple example of nonlinear curve fitting where nls seems to get the answer wrong on a very simple exponential fit (my R version 2.7.2). Look at this code below for a very basic curve fit using nls to fit to (a) a logarithmic and (b) an exponential curve. I did the fits using self-start functions and I compared the results with a more simple fit using a straight lm()

Hi, I have a little problem with table header. I am enclosing my TOY example: I have a tab separated file(tsv) with two columns as follow: \\disk(c:) \\processor(1) 322 40 422 60 I read the file using read.table as follow: tab<-read.table("c:/R/file1.tsv", header = TRUE, sep = "\t") ; but when I print it i.e print(tab);

Hi, I am facing the problem that I want to plot a histogram chart set freq to true and overlay with normal or weibull or exponential distribution curve. The sample code is shown as below: >samp<-c(-8.2262,-8.2262,-8.2262,-8.20209,-8.09294,-8.07321,-8.07321, -8.07321,-8.07175,-8.04948,-8.04948,-8.04948,-8.03848,-8.03848,

Hello there, I am trying to fit an exponential fit using Least squares to some data. #data x <- c(1 ,10, 20, 30, 40, 50, 60, 70, 80, 90, 100) y <- c(0.033823, 0.014779, 0.004698, 0.001584, -0.002017, -0.003436, -0.000006, -0.004626, -0.004626, -0.004626, -0.004626) sub <- data.frame(x,y) #If model is y = a*exp(-x) + b then fit <- nls(y ~ a*exp(-x) + b, data = sub, start

Hi, I am trying to fit experimental points by exponemtial curve my data are stored into a matrix data the first column is the geographical point (a number = data[,1] ) ( I would like to plot several graphes at the same time) the second column is the time of measurement (x in the plot) the third column is a speed (y in the plot) if we assume the point are folowing this exponential behaviour

Hi Team, I am trying to run kmeans in R, and I need to save the different clusters into different folders. How can I achieve this? # this is how my data looks. $ *cat 1.tsv | head* userid bookid rating bookTotalRatings bookAvgRating userTotalRatings userAvgRating 1 100 0 24 2.7916666666666665 291 2.6735395189003435 2 200 7 24 2.9583333333333335 6 7.0

Hi everybody, I try to do an exponential model with decreasing. In my data, there is no data missing but there negative values. I adapted this following code whose the origin code comes from in this forum: Regress<-read.table("C:\\Users\\Regression.csv",sep=";",dec=",",header=TRUE) Regress f <- function(x,a,b) {a * exp(b * x)} x<-Regress$EWT

Hi, I'm a new user or R and I try to concatenate a several rows according with the value in a column. this is my data.frame and I want to concatenate my data.frame according with the column "b" and make a new data.frame with the information in the others columns. >table1 a b c d 1 E001234 TSA IP234 like_domain 2

Dear R users, Does anybody know if there is an R function (package) to fit a two-terms exponential model like y = a*exp(bx) + c*exp(dx) where y is dependent variable and x is independent variable. MATLAB has a Curve Fitting Toolbox to implement this fitting, but I don't know if there is an R package for this fitting. Thank you! Deming Mi

Hi, I ran a linear regression on a data set and got an Rsq of about .27. The plot looks as though an exponential curve would be a better fit. What codes do I use to do this? Thank you, Ryan Munroe [[alternative HTML version deleted]]

Dear All, I have two questions regarding distribution fitting. I have several datasets, all left-truncated at x=1, that I am attempting to fit distributions to (lognormal, weibull and exponential). I had been using fitdistr in the MASS package as follows: fitdistr<-(x,"weibull") However, this does not take into consideration the truncation at x=1. I read another posting in this