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

1

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

0

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

2

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

5

"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

1

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

1

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

1

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

3

(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

0

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

2

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

0

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

1

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

6

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

0

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

1

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

0

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

1

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

11

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

2

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
http://bit.ly/hOgK9h
Any suggestion is appreciated.
Cheers
Lorenzo

2007 Apr 26

1

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: