similar to: nls and rbinom function: step factor 0.000488281 reduced below 'minFactor' of 0.000976562

Displaying 20 results from an estimated 400 matches similar to: "nls and rbinom function: step factor 0.000488281 reduced below 'minFactor' of 0.000976562"

2011 Mar 28
error in nls, step factor reduced below minFactor
Hello, I've seen various threads on people reporting: step factor 0.000488281 reduced below `minFactor' of 0.000976563 While I know how to set the minFactor, what I'd like to have happen is for nls to return to me, the last or closest fitted parameters before it errors out. In other words, so I don't get convergence, I'd still like to acquire the values of the parameters
2001 Aug 03
step factor below minimum
I am trying to fit the 4-parameter logistic model with SSfpl. The estimation is terminated with a message "step factor 0.000488281 reduced below 'minFactor' of 0.000976562". I tried to change the minFactor with nls.control(minFactor=yy) with no apparent success. A call of nls.control() without arguments always shows the value of 0.000976562. Also the estimation terminates as
2013 Oct 03
SSweibull() : problems with step factor and singular gradient
SSweibull() :  problems with step factor and singular gradient Hello I am working with growth data of ~4000 tree seedlings and trying to fit non-linear Weibull growth curves through the data of each plant. Since they differ a lot in their shape, initial parameters cannot be set for all plants. That’s why I use the self-starting function SSweibull(). However, I often got two error messages:
2008 May 28
"rbinom" not using probability of success right
I am trying to simulate a series of ones and zeros (1 or 0) and I am using "rbinom" but realizing that the number of successes expected is not accurate. Any advice out there. This is the example: N<-500 status<-rbinom(N, 1, prob = 0.15) count<-sum(status) 15 percent of 500 should be 75 but what I obtain from the "count" variable is 77 that gives the probability of
2013 May 23
sample(c(0, 1)...) vs. rbinom
Greetings.? My wife is teaching an introductory stat class at UC Davis.? The class emphasizes the use of simulations, rather than mathematics, to get insight into statistics, and R is the mandated tool.?? A student in the class recently inquired about different approaches to sampling from a binomial distribution.? I've appended some code that exhibits the idea, the gist of which is that using
2013 Oct 27
nls function error
data(Boston, package='MASS') y <- Boston$nox x <- Boston$dis nls(y~ A + B * exp(C * x), start=list(A=1, B=1, C=1)) Error in nls(y ~ A + B * exp(C * x), start = list(A = 1, B = 1, C = 1), : step factor 0.000488281 reduced below 'minFactor' of 0.000976562 I don't know how to fix this error. I think my problem is that I set the wrong start. Could somebody help please?
2011 Jun 12
Error in NLS example in the documentation
Hello there, I am trying to use R function NLS to analyze my data and one of the examples in the documentation is - ## the nls() internal cheap guess for starting values can be sufficient: x <- -(1:100)/10 y <- 100 + 10 * exp(x / 2) + rnorm(x)/10 nlmod <- nls(y ~ Const + A * exp(B * x), trace=TRUE) plot(x,y, main = "nls(*), data, true function and fit, n=100")
2003 Aug 28
(no subject)
Dear All, A couple of questions about the nls package. 1. I'm trying to run a nonlinear least squares regression but the routine gives me the following error message: step factor 0.000488281 reduced below `minFactor' of 0.000976563 even though I previously wrote the following command: nls.control(minFactor = 1/4096), which should set the minFactor to a lower level than the default
2007 Jun 14
nlsList problems: control option does not effect output and strange environment search
Dear R-helpers, I'm using R 2.5.0 under Windows and am trying to use nlsList from nlme 3.1-80 with the selfstart function for the four parametric logistic function. My first test went well, but now I'm trying to do some more sophisticated things and it does not work anymore. I simulate my data from a five parametric logistic function like this:
2012 Oct 09
Constant Error in R
Hi good R folks, I am hoping that you could help me resolve this issue. I tried finding answers online but to no avail. I keep getting this "Error in x^2 : non-numeric argument to binary operator" using multiple different codes, ones which have been verified to work by my professor and other students. I tried reinstalling R completely and it still didn't fix the issue. I am using
2002 Mar 19
MASS Book Exercise
Hi, In the third edition of the MASS book, Chapter 8, Page 252 ~ 253. I tried applying the same technique on using a negative exponential model (as suggested in Exercise 1), and trying to get a confidence interval. What I have changed is follows: expn <- function(b0, b1, th, x) { temp <- exp(-x/th) model.func <- b0 + b1 * temp # Differentiate temp derive.negexp
2011 Oct 24
nonlinear model
Hello, I am trying to do a nonlinear model using the "nls" command in R software. The data I am using is as follows: A<-c(7.132000,8.668667,9.880667,8.168000,10.863333,10.381333,11.059333,7.589333,4.716667,4.268667,7.265333,10.309333,8.456667,13.359333,8.624000,13.571333,12.523333,4.084667 ,NaN,NaN)
2013 Feb 08
Add text A, B, C and D on multiple ordered plot
Dear list, Is there a elegant way to name multiple ordered plot as A, B, C and D? Just put A, B, C and D on the top left corner of each plot. Usually I do it in Illustrator, but I think in R should there is a way. Could you please provide a example? Thank you very much in advance.
2004 May 27
specifying starting values in nlsList/conversion problems
Hi I am using nlsList from the nlme package to estimate group specific coefficient sets to get a first impression of the structure of coefficients in relation to potential predictor variables. In some cases I got coefficients in other there are conversion problems due to bad start values I guess, resulting in typical error messages as known from nls: Error in nls(formula = formula, data = data,
2000 Aug 10
Problem with density()?
Hello, all, I'm running Version 1.1.0 (June 15, 2000), on Mandrake 6.1 Linux. I think that I'm getting nonsense results from the density function. When I feed it a sample generated by v<-runif(1000,0,1), I get back some small negative numbers for density values, as follows: >v<-runif(1000,0,1) >
2013 Mar 21
step halving factor reduced below minimum
Hello,   I am attempting to use nlme to model the response of 19 groups.  I am able to get a reasonable fit of all of the groups to the observed data using an exponential decay model (a*exp-x*b).  The problem is that when I plot the fitted values to residuals, it demonstrates a pattern of increasing variance.   I attempt to model this variance using   Sig3.nlme <- update(Sig2.nlme, weights =
2003 Dec 17
step halving factor reduced below minimum
Dear Splus and R users: I have a problem in fitting a NLME model, the error message is: "step halving factor reduced below minimum in PNLS step" What does it mean and how to fix the problem, could anyone help me about it? Any suggestion/help would be greatly appreciated. Mei
2007 Oct 10
please help me
dear list I am student M.S. statistics in department statistics . I am working in the function "nls" in the [R 2.3.1] with 246 data and want to fit the "exp" model to vectors( v and u ) but I have a problem to use it u 5.000000e-13 2.179057e+03 6.537171e+03 1.089529e+04 1.525340e+04 1.961151e+04 2.396963e+04 2.832774e+04 3.268586e+04 3.704397e+04 4.140209e+04
2011 Feb 25
Visualizing Points on a Sphere
Dear All, I need to plot some points on the surface of a sphere, but I am not sure about how to proceed to achieve this in R (or if it is suitable for this at all). In any case, I am not looking for really fancy visualizations; for instance you can consider the images between formulae 5 and 6 at Any suggestion is appreciated. Cheers Lorenzo
2007 Apr 26
gnls warning message
Dear R users; I was trying to fit a nonlinear model using gnls (nlme version 3.1-80, R 2.5.0, WinXP) and I got the following error and warning message: Error in gnls(ht ~ a1 * hd * (1 - a2 * exp(-a3 * (dbh/dq2))), data = hdat, : Step halving factor reduced below minimum in NLS step In addition: Warning message: $ operator is deprecated for atomic vectors, returning NULL in: