Displaying 20 results from an estimated 8000 matches similar to: "bivariate function in gam model"
2004 Mar 05
3
Lyapunov exponent code for time series
Dear all,
Has anyone worked on coding for calculating Lyapunov Exponent for a time
series data? or any package is available for computing Lyapunov?
Please advice and many thanks in advance.
Catherine X Wang
2004 Jul 06
2
lme: extract variance estimate
For a Monte Carlo study I need to extract from an lme model
the estimated standard deviation of a random effect
and store it in a vector. If I do a print() or summary()
on the model, the number I need is displayed in the Console
[it's the 0.1590195 in the output below]
>print(fit)
>Linear mixed-effects model fit by maximum likelihood
> Data: datag2
> Log-likelihood:
2004 Apr 22
1
Lyapunov exponent?
Hello,
Does anybody know if there is somewhere in R a function to calculate the
Lyapunov exponent in a time series?
Thanks,
Philippe Grosjean
.......................................................<??}))><....
) ) ) ) )
( ( ( ( ( Prof. Philippe Grosjean
\ ___ )
\/ECO\ ( Numerical Ecology of Aquatic Systems
/\___/ ) Mons-Hainaut University, Pentagone
/ ___ /( 8, Av. du
2007 Sep 05
1
Monotone splines
Hello, i have a little problem with R and i hope you can help me.
I want to use splines to estimate a function but i want to force the interpolation to be monotone. Is this possible with R ?
Thank you,
Rémi.
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2004 Apr 28
2
Matrix efficiency in 1.9.0 vs 1.8.1
I'm seeking some advice on effectively using the new Matrix
library in R1.9.0 for operations with large dense matrices. I'm working on
integral operator models (implemented numerically via matrix operations)
and except for the way entries are generated, the examples below really are
representative of my problem sizes.
My main concern is speed of large dense matrix multiplication.
In R
2003 Nov 05
3
using LSODA in R
R help list subscribers,
I am a new user of R. I am attempting to use R to explore a set of
equations specifying the dynamics of a three trophic level food chain. I
have put together this code for the function that is to be evaluted by
LSODA. My equations Rprime, Cprime, and Pprime are meant to describe the
actual equation of the derivative. When I run LSODA, I do not get the
output that
2008 Aug 20
5
GAM-binomial logit link
Dear all,
I'm using a binomial distribution with a logit link function to fit a GAM model. I have 2 questions about it.
First i am not sure if i've chosen the most adequate distribution. I don't have presence/absence data (0/1) but I do have a rate which values vary between 0 and 1. This means the response variable is continuous even if within a limited interval. Should i use
2007 Dec 13
1
Probelms on using gam(mgcv)
Dear all,
Following the help from gam(mgcv) help page, i tried to analyze my
dataset with all the default arguments. Unfortunately, it can't be run
successfully. I list the errors below.
#m.gam<-gam(mark~s(x,y)+s(lstday2004)+s(slope)+s(ndvi2004)+s(elevation)+s(disbinary),family=binomial(logit),data=point)
2008 Jan 08
3
GAM, GLM, Logit, infinite or missing values in 'x'
Hi,
I'm running gam (mgcv version 1.3-29) and glm (logit) (stats R 2.61) on
the same models/data, and I got error messages for the gam() model and
warnings for the glm() model.
R-help suggested that the glm() warning messages are due to the model
perfectly predicting binary output. Perhaps the model overfits the data? I
inspected my data and it was not immediately obvious to me (though I
2023 Feb 11
1
GAM with binary predictors
Dear R-experts,
I am trying to fit a GAM with 2 binary predictors (variables coded 0,1). I guess I cannot just smooth binary variables. By the way I code them as 0=no,1=yes, then mgcv will think those variables are numeric.?
I have tried to change 0 and 1 in no and yes. It does not work.
How to solve my problem. Here below my toy example. Many thanks.
Best,
Sacha
?
########################
2005 Aug 17
1
GLM/GAM and unobserved heterogeneity
Hello,
I'm interested in correcting for and measuring unobserved
heterogeneity ("missing variables") using R. In particular, I'm
searching for a simple way to measure the amount of unobserved
heterogeneity remaining in a series of increasingly complex models
(adding additional variables to each new model) on the same data.
I have a static database of 400,000 or
2023 Feb 16
1
GAM with binary predictors
Dear Sacha,
use glm() in this case. I'd rather code the covariable as TRUE / FALSE or
as a factor.
Best regards,
ir. Thierry Onkelinx
Statisticus / Statistician
Vlaamse Overheid / Government of Flanders
INSTITUUT VOOR NATUUR- EN BOSONDERZOEK / RESEARCH INSTITUTE FOR NATURE AND
FOREST
Team Biometrie & Kwaliteitszorg / Team Biometrics & Quality Assurance
thierry.onkelinx at inbo.be
2007 Dec 13
1
Two repeated warnings when runing gam(mgcv) to analyze my dataset?
Dear all,
I run the GAMs (generalized additive models) in gam(mgcv) using the
following codes.
m.gam
<-gam(mark~s(x)+s(y)+s(lstday2004)+s(ndvi2004)+s(slope)+s(elevation)+disbinary,family=binomial(logit),data=point)
And two repeated warnings appeared.
Warnings$B!'(B
1: In gam.fit(G, family = G$family, control = control, gamma = gamma, ... :
Algorithm did not converge
2: In gam.fit(G,
2005 May 06
2
bivariate normal cdf
-- R Help List --
I am looking for a bivariate normal cdf routine in R. I have some fortran routines for this, which appear to be based on 15-point quadrature. Any guidance/suggestions on making these in loadable R-functions would be appreciated.
Thanks,
Dan
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Daniel A. Powers, Ph.D.
Department of Sociology
University of Texas at Austin
2008 Mar 31
1
unexpected GAM result - at least for me!
Hi
I am afraid i am not understanding something very fundamental.... and does not matter how much i am looking into the book "Generalized Additive Models" of S. Wood i still don't understand my result.
I am trying to model presence / absence (presence = 1, absence = 0) of a species using some lidar metrics (i have 4 of these). I am using different models and such .... and when i
2010 Feb 15
1
GAM for non-integer proportions
Dear list,
I´m using the mgcv package to model the proportion by weight of certain prey
on the stomach content of a predator. This proportion is the ratio of two
weights (prey weight over stomach weight), and ranges between 0 and 1. The
variance is low when proportion is close to 0 and 1, and higher at
intermediate values.
It seems that the best way to go is to model this using the
2005 Dec 12
2
Bivariate Splines in R
Hi..,
is there a function in R to fit bivariate splines
?
I came across 'polymars' (POLSPLINE) and 'mars' (mda)
packages. Are these the one to use or are there other
specific commands?
Thanks.
Harsh
2012 May 03
1
conducting GAM-GEE within gamm4?
Dear R-help users,
I am trying to analyze some visual transect data of organisms to generate a
habitat distribution model. Once organisms are sighted, they are followed
as point data is collected at a given time interval. Because of the
autocorrelation among these "follows," I wish to utilize a GAM-GEE approach
similar to that of Pirotta et al. 2011, using packages 'yags' and
2018 Mar 04
2
Random effect in GAM (mgcv)
Dear R users,
I am using the *mgcv package* to model the ratio of hectares of damaged
culture by wild boar in french departments according to some
environmental covariates. I used a _Beta distribution_ for the response.
For each department, we estimated the damaged in 3 different culture
types (??Culture??). Our statistical individual are therefore the
department crossed by the culture
2008 Oct 10
2
bivariate non-parametric smoothing
Hi,
I was wondering if there is a function in R which performs bivariate non parametric smoothing
which allows for the possibility of including some weights in the smoothing (for each data points
in my grid I have some predefined weights that I would like to include in the smoothing).
Thanks,
Ben
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