similar to: nls()

Displaying 20 results from an estimated 2000 matches similar to: "nls()"

2011 Aug 09
1
nls, how to determine function?
Hi R help, I am trying to determine how nls() generates a function based on the self-starting SSlogis and what the formula for the function would be. I've scoured the help site, and other literature to try and figure this out but I still am unsure if I am correct in what I am coming up with. ************************************************************************** dat <-
2012 Jul 01
4
geom_boxplot
Also, it is possible to change "ylim" also? 2012/7/1 li li <hannah.hlx@gmail.com> > Dear all, > I have a few questions regarding the boxplot output from the > "geom_boxplot" function. > Attached is the output I get. Below are my questions: > > 1. How can I define the xlab and ylab myself? > Also I would like to remove
2008 Feb 18
2
skip non-converging nls() in a list
Howdee, My question appears at #6 below: 1. I want to model the growth of each of a large number of individuals using a 4-parameter logistic growth curve. 2. nlme does not converge with the random structure that I want to use. 3. nlsList does not converge for some individuals. 4. I decided to go around nlsList using: t(sapply(split(data, list(data$id)), function(subd){coef(nls(mass ~
2012 Aug 06
4
Overlay Histogram
Dear all, For two sets of random variables, say, x <- rnorm(1000, 10, 10) and y <- rnorm(1000. 3, 20). Is there any way to overlay the histograms (and density curves) of x and y on the plot of y vs. x? The histogram of x is on the x axis and that of y is on the y axis. The density curve here is to approximate the shape of the distribution and does not have to have area 1. Thank you
2010 Mar 13
1
testing parallelism of does-response curves using nls()
Hi, I am trying to use F test or Chi-square test to test if 2 5-parameter (A, B, xmid, scal and H) logistic curves are parallel based on residual sum of squares. What's usually done is to first fit the 2 curves using a constraint (or global) model where all parameters are kept the same except for "xmid"; then fit 2 independent curves using unconstraint models where all 5 parameters
2005 Jun 02
1
nls.control: increasing number of iterations
Hello, I'm using the nls function and would like to increase the number of iterations. According to the documentation as well as other postings on R-help, I've tried to do this using the "control" argument: nls(y ~ SSfpl(x, A, B, xmid, scal), data=my.data, control=nls.control(maxiter=200)) but no matter how much I increase "maxiter", I get the following error
2010 Jul 07
1
Why do <none>s appear in the list of predictor variables in logistic regression using 'step' or 'stepAIC' function?
Would anyone help me solve my problem with R, please? I am very new to R. I am doing logistic regression analysis on the presence/absence of salamanders using several predictor variables, as shown below. I have checked my data, but I didn't find any 'NA' or empty cells. When I used step() or stepAIC to select significant predictor variables, <none>s appear to places where
2003 Feb 22
2
4-parameter logistic model
Dear R users I'm a new user of R and I have a basic question about the 4-parameter logistic model. According to the information from Pinheiro & Bates the model is: y(x)=theta1+(theta2-theta1)/(1+exp((theta3-x)/theta4)) == y(x)=A+(B-A)/(1+exp((xmid-input)/scal)) from the graph in page 518 of the book of the same authors (mixed models in S) theta 1 corresponds to the horizontal asymptote
2012 Aug 07
2
Rcolorbrewer Package
Hi all, I am trying to download the Rcolorbrewer package from Cran http://cran.r-project.org/web/packages/RColorBrewer//index.html It seems the files have been removed. Does anyone know where can I download the package? Thanks. Hannah [[alternative HTML version deleted]]
2017 Oct 20
1
Error messages using nonlinear regression function (nls)
Thank you Martin. If I understand correctly, OP could do wheat.list <- nlsList(Prop ~ SSfpl(end, A, B, xmid, scal), data=wlg) or add some small value to all zeroes wlg$prop < -wlg$Prop+1e-7 wheat.list <- nlsList(prop ~ SSlogis(end,Asym, xmid, scal), data=wlg) which gives fairly reasonable results. plot(augPred(wheat.list)) Am I correct? Cheers Petr > -----Original Message-----
2010 Jul 23
3
Figures in Latex
Hi all, I want to add 6 plots in the format of 2 columns and 3 rows as one figure in latex. The plots are in .eps file. I know how to add 2 plots side by side, but could not figure out how to do multiple rows. I know this may not be the right place to ask such a question. But I do not know who to ask, so just try my luck here. Thank you in advance.
2002 Sep 27
2
How to apply SSfpl with binary data
Dear R-help subscribers Would you tell me how to apply SSfpl with binary data as below? Unfortunately, there is not the EXAMPLE in help(SSfpl) for binary data but for quantitative data(Chick). V1: dose V2: log-transformed dose V3: response (rate) V1 V2 V3 1 0.775 -0.2548922 0.1666667 2 5.000 1.6094379 0.8148148 3 10.000 2.3025851 0.5000000 4 20.000 2.9957323
2010 May 28
2
problem with a function
Hi all, I have a function rho.f which gives a list of estimators. I have the following problems. rho.f(0.3) gives me the right answer. However, if I use rho.f(corr[4]) give me a different answer, even though corr[4]==0.3. This prevents me from using a for loop. Can someone give me some help? Thank you very much in advance. Hannah >
2011 Sep 03
3
question with uniroot function
Dear all, I have the following problem with the uniroot function. I want to find roots for the fucntion "Fp2" which is defined as below. Fz <- function(z){0.8*pnorm(z)+p1*pnorm(z-u1)+(0.2-p1)*pnorm(z-u2)} Fp <- function(t){(1-Fz(abs(qnorm(1-(t/2)))))+(Fz(-abs(qnorm(1-(t/2)))))} Fp2 <- function(t) {Fp(t)-0.8*t/alpha} th <- uniroot(Fp2, lower =0, upper =1,
2017 Oct 20
0
Error messages using nonlinear regression function (nls)
>>>>> PIKAL Petr <petr.pikal at precheza.cz> >>>>> on Fri, 20 Oct 2017 06:33:36 +0000 writes: > Hi > Keep your messages in the list, you increase your chance to get some answer. > I changed your data to groupedData object (see below), but I did not find any problem in it. > plot(wlg) > gives reasonable picture and I am
2012 Jun 28
6
Help
Dear all, I need some help on plotting multiple boxplots on one figure. I have three matrix A, B and C. Each of them is a 1000 by 10 matrix. The 10 columns of all three matrix correspond to the 10 values of the same parameter, say k=1, ..., 10. I want to make a plot where x axis represents different values of k. For each k value, I want to plot three boxplots, one on top of another. For
2013 Mar 14
4
plotting
Hi alL, I have a data frame with 4 columns: "value", "time", "group" and "id". I would like to plot "value" vs. "time" with different colors for different levels of "group" and different symbols for different values of "id". I think I could do this but I would like to see what is an easier way to plot the
2005 Apr 23
1
start values for nls() that don't yield singular gradients?
I'm trying to fit a Gompertz sigmoid as follows: x <- c(15, 16, 17, 18, 19) # arbitrary example data here; y <- c(0.1, 1.8, 2.2, 2.6, 2.9) # actual data is similar gm <- nls(y ~ a+b*exp(-exp(-c*(x-d))), start=c(a=?, b=?, c=?, d=?)) I have been unable to properly set the starting value '?'s. All of my guesses yield either a "singular gradient" error if they
2012 Aug 15
4
Import Data from Excel
Dear all, I want to import just part of an excel data file into R. I would like to have the data imported without rownames or colume names. I used read.delim("clipboard", header=F). Somehow even though I added the argument "header=F", I still have the row names V1, V2, ..., Does anyone know how to fix this? Thanks very much in advance. Hannah [[alternative
2017 Jun 02
0
subletting an array according to dimnames
Have you tried P2["20", "10", "0"] ? Jean On Thu, Jun 1, 2017 at 3:10 PM, li li <hannah.hlx at gmail.com> wrote: > Hi all, > I have a three dimensional array with the corresponding dimension names. > I would like to subset the array according to the dimension names. For > example, > suppose I want to extract the values corresponding to A=20,