similar to: Enforcing inequality bounds and heteroscedasticity in a GAM or GLM

Displaying 20 results from an estimated 6000 matches similar to: "Enforcing inequality bounds and heteroscedasticity in a GAM or GLM"

2012 Jul 11
2
Modifying the design matrix X in GAMS to suit data assimilation
I have a data assimilation problem that might be amenable to the use of GAMS, but I am not sure how feasible it is to implement. I was told the R mailing list was a great resource. My observations are spatiotemporal salinity in the San Francisco Bay at a number of instruments over a few days. The thing that I want to fit is the initial condition for a salt transport model at the beginning of this
2010 May 19
3
offset in gam and spatial scale of variables
Hi, We are analizing the relationship between the abundance of groupers in line transects and some variables. We are using the quasipoisson distribution. Do we need to include the length of the transects as an offset if they all have the same length?? Also, can we include in the gam models variables that are measured at different spatial scales? We have done an analysis to see what variables
2012 Jan 16
2
Object not found using GAMs in MGCV Package
This is my first time running GAMs in R. My csv file has these column headings: "X" "Y" "Sound" "Atlantic" "Blacktip" "Bonnet" "Bull" "Finetooth" "Lemon" "Scalloped" "Sandbar" "Spinner" "Abundance" "Diversity"
2007 Nov 25
1
GAM with constraints
Hi, I am trying to build GAM with linear constraints, for a general link function, not only identity. If I understand it correctly, the function pcls() can solve the problem, if the smoothness penalties are given. What I need is to incorporate the constraints before calculating the penalties. Can this be done in R? Any help would be greately appreciated. -- View this message in context:
2013 Feb 20
1
a priori power analysis for glm, family = poisson
Dear R/statistics wizards, This may be more of a statistics question than an R one, but I’m hoping that someone has the time to help. I’ve already consulted a few local statisticians and I’ve not yet received a clear answer. Before I start an experiment I want to conduct an a priori power analysis test for a Generalized Linear Model, family = poisson. The response variables will be counts.
2010 Sep 16
0
problems trying to reproduce structural equation model using the sem package
Hello, I've been unsuccessfully trying to reproduce a sem from Grace et al. (2010) published in Ecological Monographs: http://www.esajournals.org/doi/pdf/10.1890/09-0464.1 The model in question is presented in Figure 8, page 81. The errors that I've been getting are: 1. Using a correlation matrix: res.grace <- sem(grace.model, S = grace, N = 190) Warning message: In sem.default(ram
2003 Mar 12
0
job opportunity
The University of Miami's Rosenstiel School of Marine and Atmospheric Sciences (RSMAS) is seeking a research associate to work with hydrographic data. The objective of the project is to develop statistical models for estimating salinity and density from observations of temperature together with knowledge of location and time. Because the relationship between salinity and temperature can be
2003 Mar 12
0
job opportunity
The University of Miami's Rosenstiel School of Marine and Atmospheric Sciences (RSMAS) is seeking a research associate to work with hydrographic data. The objective of the project is to develop statistical models for estimating salinity and density from observations of temperature together with knowledge of location and time. Because the relationship between salinity and temperature can be
2011 Feb 01
1
Setting maximum value of the legend on an image.plot and animation
Hello, I'm doing the following: library(ncdf) library(fields) library(animation) saline <- open.ncdf("salinity_1990.nc") salt = get.var.ncdf(nc=saline, varid="Salinity") # create an animation of the complete temporal domain in the ncdf file. saveHTML({ for (i in 1:364) { image.plot(salt[, , i]) } }, img.name = "salinity.img",
2012 Dec 12
2
help with predict.glm, and charting with factors
Dear R Wizards, After much frustration and days of confusion I have finally broken down and am asking for help, which I don’t like doing, but I just can’t figure this one out on my own. I’ve conducted a laboratory experiment testing the effects of temperature and salinity on whether or not a biological event will occur (Go or NoGo). I’ve coded the factors temperature and salinity as factors for
2005 Mar 15
0
trellis/ panel.superpose/ passing in superscripts/ groups
Background: OS: Linux Mandrake 10.1 release: R 2.0.0 editor: GNU Emacs 21.3.2 front-end: ESS 5.2.3 --------------------------------- Colleagues I'm plotting fish egg densities in temperature-salinity space (i.e. mean temperature ~ mean salinity | fish egg densities) for two survey years. The bivariate plot is overlaid on a temperature ~ salinity plot (not means) showing the distribution of
2013 Mar 19
0
linear model with equality and inequality (redundant) constraints
Dear R-users, in the last days I have been trying to estimate a normal linear model with equality and inequality constraints. Please find below a simple example of my problem. Of course, one could easily see that, though the constraints are consistent, there is some redundancy in the specific constraints. Nevertheless my actual applications can get much larger and I would not like to manually
2012 Oct 19
2
Which package/function for solving weighted linear least squares with inequality and equality constraints?
Dear All, Which package/function could i use to solve following linear least square problem? A over determined system of linear equations is given. The nnls-function may would be a possibility BUT: The solving is constrained with a inequality that all unknowns are >= 0 and a equality that the sum of all unknowns is 1 The influence of the equations according to the solving process is
2011 Sep 08
3
global optimisation with inequality constraints
Dear All, I would like to minimise a nonlinear function subject to linear inequality constraints as part of an R program. I have been using the constrOptim function. I have tried all of the methods that come with Optim, but nothing finds the correct solution. If I use the correct solution as the vector of starting values, though, my program does output the correct solution and optimum - the
2003 Sep 26
1
least squares regression using (inequality) restrictions
Dear R Users, I would like to make a lesast squares regression similar to that what is done by the command "lm". But additionally, I would like to impose some restrictions: 1) The sum of all regression coefficients should be equal to 1. 2) Each coefficient should assume a value between 0 and 1. (inequality restrictions) Which command is the best to use in order to solve this problem
2017 Aug 16
0
{nlme} Question about modeling Level two heteroscedasticity in HLM
If you don't get a response it is because you did not read the Posting Guide which indicates that the R-sig-ME mailing list is where this question would have been on-topic. -- Sent from my phone. Please excuse my brevity. On August 16, 2017 6:17:03 AM PDT, b88207001 at ntu.edu.tw wrote: >Hello dear uesRs, > >I am working on modeling both level one and level two
2017 Aug 16
0
{nlme} Question about modeling Level two heteroscedasticity in HLM
A better place for this post would be on R's mixed models list: r-sig-mixed-models . Cheers, Bert Bert Gunter "The trouble with having an open mind is that people keep coming along and sticking things into it." -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip ) On Wed, Aug 16, 2017 at 6:17 AM, <b88207001 at ntu.edu.tw> wrote: > Hello dear
2010 Jan 21
1
Double inequality with plotmath
Hello, I'm fairly new to R and I can't work out how to produce a double inequality like (LaTeX) $0 \leq x \leq 1$ in the legend of a graph. If I try > legend(50, 0.1, legend = c(expression(0 <= x <= 1), c(2 <= x <= 3)), pch = c(1,1), col = c(2, 3)) then I get an error message "unexpected '<=' in ...". I've checked the help files for plotmath and
2006 Aug 31
0
Moving Window regressions with corrections for Heteroscedasticity and Autocorrelations(HAC)
# Using Moving/Rolling Windows, here we do an OLS Regression with corrections for #Heteroscedasticity and Autocorrelations (HAC) using Newey West Method. This code is a #extension of Ajay Shah?s code for moving windows simple OLS regression. # The easiest way to adjust for Autocorrelations and Heteroscedasticity in the OLS residuals is to #use the coeftest function that is included in the
2006 Sep 22
2
inequality with NA
Dear everybody! take a<-c(5,3,NA,6). if(a[1]!=NA){b<-7} if(a[3]!=5){b<-7} if(a[3]!=NA){b<-7} if(a[3]==NA){b<-7} will alltogeather return Fehler in if (a[1] != NA) { : Fehlender Wert, wo TRUE/FALSE n?tig ist (or simularly). Somehow this is logical. But how else should I get out, whether a certain vector-component has an existing value? Thank you in advance! Yours, Mag. Ferri