similar to: Estimating values from Segmented Package

Displaying 20 results from an estimated 30000 matches similar to: "Estimating values from Segmented Package"

2006 Aug 02
0
Trying to use segmented in a function
Hi folks I wonder if anyone can help me. I want to run some simulations to see how big a sample size might be necessary to distinguish a curved bivariate relationship (e.g. something that might be best described by a quadratic model) from a relationship that is two straight lines with a sudden change in slope (e.g. something best described by a breakpoint regression). I am using
2012 Nov 16
1
Interpretation of davies.test() in segmented package
My data: I have raw data points that form a logit style curve as if they were a time series. Which is to say they form 3 distinct lines with 3 distinct slopes in backwards z pattern. A certain class of my data looks essentially flat to the eye with marginal oscillation. What is important to me is the x value at which the state change is occurring, in other words, the break point Use of
2012 May 08
1
Error with psi value for 'segmented' package for R
Hi everyone, while trying to use 'segmented' (R i386 2.15.0 for Windows 32bit OS) to determine the breakpoint I got stuck with an error message and I can't find solution. It is connected with psi value, and the error says: Error in seg.glm.fit(y, XREG, Z, PSI, weights, offs, opz) : (Some) estimated psi out of its range This is the code I am using:
2005 Jun 10
0
Replies of the question about robustness of segmented regression
I appreciate to Roger Koenker, Achim Zeileis and Vito Muggeo for their informative answers. Listed below is unedited replies I got followed by the question I posted. Kyong 1. Roger Koenker: You might try rqss() in the quantreg package. It gives piecewise linear fits for a nonparametric form of median regression using total variation of the derivative of the fitted function as a penalty
2006 Jan 18
1
Breakpoints for multiple variables using Segmented
Hi all, I am using the package ?Segmented? to estimate logistic regression models with unknown breakpoints (see Muggeo 2003 Statistics in Medicine 22:3055-3071). In the documentation it suggests that it might be possible to include several variables with breakpoints in the same model: ?Z = a vector or a matrix meaning the (continuous) explanatory variable(s) having segmented relationships with
2012 Jun 01
1
Finding multiple breakpoints - 'segmented' ?
Hello, I'm attempting to find multiple breakpoints in an association of my response variable (R.AUC) with two explanatory variables ('s.size' and 'bedekking'). The association between 's.size' and 'R.AUC' shows a plateau, but the value when this plateau is reached is differs for different values of 'bedekking'. Initially I thought these different
2012 May 25
1
Breakpoint in logistic GLM with 'segmented' package - error: replacement length zero
Hello all, I've been having trouble with assessing a breakpoint in a logistic GLM with two explanatory variables. For this analysis I've been using the 'segmented' package version 0.2-9.1. But I keep getting an error and I don't see where I would be going awry. The situation is the following: Two explanatory variables: bedekking - a variable with possible values between 0 and
2013 Jan 12
1
Question on broken-line regression: 'segmented' or alternative
Dear R-Users, I have a question concerning the determination of breakpoints and comparison of slopes from broken-line regression models. Although this is rather a standard problem in data analysis, all information I gathered so far, did not answer my questions. I added a subsetted example of my data. Basically it is a timeseries of recorded phenotypes in three different groups of plants. You
2011 Feb 03
0
Generalized Estimating Equations and a Reviewer Question I can’t answer
I am using the R statistical package in a pretty straightforward manner, just interested in getting summary statistics and reliable estimates of means, variances, confidence intervals, p-values using standard tests, etc. I've been using the generalized estimating equation package because I often deal with repeatedly sampled pairs of data from the same source, and my reading (and my
2007 Mar 16
0
Segmentation fault in estimating structural equation models with the SEM package.
Dear R-users, I am running a large number of simulations and estimating a structural equation model for each one using the SEM package. Each run of my program has around 8000 simulations. Most of the time the program completes all of them correctly but sometimes I get a segmentation fault in the sem routine and my program stops with the following error message: > *** caught
2007 Dec 06
2
Segmented regression
Hello all, I have 3 time series (tt) that I've fitted segmented regression models to, with 3 breakpoints that are common to all, using code below (requires segmented package). However I wish to specifiy a zero coefficient, a priori, for the last segment of the KW series (green) only. Is this possible to do with segmented? If not, could someone point in a direction? The final goal is to
2011 Nov 15
1
Estimating model parameters for system of equations
Hi all, I'm trying to estimate model parameters in R for a pretty simple system of equations, but I'm having trouble. Here is the system of equations (all derivatives): eqAlgae <- (u_Amax * C_A) * (1 - (Q_Amin / Q_A)) eqQuota <- (p_max * R_V) / (K_p + R_V) - ((Q_A-Q_Amin)*u_Amax) eqResource <- -C_A * (p_max * R_V) / (K_p + R_V) eqSystem <- list(C_A = eqAlgae, Q_A = eqQuota,
2007 Feb 02
1
Fitting Weighted Estimating Equations
Hello Everybody: I am searching for an R package for fitting Generalized Estimating Equations (GEE) with weights (i.e. Weighted Estimating Equations). From the R documentation I found "geese(geepack)" for fitting Generalized Estimating Equations. In this documentation, under the paragraph “weights” it has been written, “an optional vector of weights to be used in the fitting process.
2012 May 03
0
MLE for estimating the parameters of the TVECM in R
Dear Mr. Matthieu Stigler i so excited for your package 'tsDyn'. firstly introduce myself, i student at Gadjah Mada University,Indonesia. i'am new user of R and applying it for solving Bi-Variate ( interest rate and inflation ) with threshold vector error correction model. now, i writing my final examination about threshold vector error correction model and i use refference from paper
2010 Jun 22
1
Generalised Estimating Equations on approx normal outcome with limited range
Dear R users I am analysing data from a group of twins and their siblings. The measures that we are interested in are all correlated within families, with the correlations being stronger between twins than between non-twin siblings. The measures are all calculated from survey answers and by definition have limited ranges (e.g. -5 to +5), though within the range they are approximately normally
2010 Jan 07
0
piecewise regression using nlme function
Is a 95% CI on a breakpoint fixed effect legitimate when the nonlinear equation is continuous but not differentiable at the breakpoint? I used the nlme to generate a non-linear mixed-effects piecewise model with initial slope zero prior to an unknown breakpoint. It did give a 95% CI for the breakpoint. Thanks Erik whole model is complex, but here is the simple equation used:
2011 Jun 28
1
Testing the proportional odds assumption of an ordinal generalized estimating equations (GEE) regression model
Dear list members, I am estimating an ordinal generalized estimating equations (GEE) regression model on repeated measurements data. Is there any way (preferably in R) to test the proportional odds assumption of this model? Thanks in advance. Andreas [[alternative HTML version deleted]]
2017 Jul 13
0
Question on Simultaneous Equations & Forecasting
Who was speaking about non-linear models in the first place??? The Klein-Model(s) and pretty much all simultaneous equation models encountered in macro-econometrics are linear and/or can contain linear approximations to non-linear relationships, e.g., production functions of the Cobb-Douglas type. Best, Bernhard -----Urspr?ngliche Nachricht----- Von: Berend Hasselman [mailto:bhh at xs4all.nl]
2017 Jul 13
0
Question on Simultaneous Equations & Forecasting
Hi Frances, I have not touched the system.fit package for quite some time, but to solve your problem the following two pointers might be helpful: 1) Recast your model in the revised form, i.e., include your identity directly into your reaction functions, if possible. 2) For solving your model, you can employ the Gau?-Seidel method (see https://en.wikipedia.org/wiki/Gauss%E2%80%93Seidel_method).
2017 Jul 13
1
Question on Simultaneous Equations & Forecasting
> On 13 Jul 2017, at 12:55, Pfaff, Bernhard Dr. <Bernhard_Pfaff at fra.invesco.com> wrote: > > Who was speaking about non-linear models in the first place??? > The Klein-Model(s) and pretty much all simultaneous equation models encountered in macro-econometrics are linear That's really not true. Klein model is linear but Oseibonsu did not say that explicitly. "Klein