Displaying 20 results from an estimated 10000 matches similar to: "gam, what is the function(s)"
2012 May 03
2
GAM, how to set qr=TRUE
Hello,
I don't understand what went wrong or how to fix this. How do I set qr=TRUE
for gam?
When I produce a fit using gam like this:
fit = gam(y~s(x),data=as.data.frame(l_yx),family=family,control =
list(keepData=T))
...then try to use predict:
(see #1 below in the traceback() )
> traceback()
6: stop("lm object does not have a proper 'qr' component.\n Rank zero or
should
2012 Mar 14
1
gam - Y axis probability scale with confidence/error lines
Hello,
How do I plot a gam fit object on probability (Y axis) vs raw values (X
axis) axis and include the confidence plot lines?
Details...
I'm using the gam function like this:
l_yx[,2] = log(l_yx[,2] + .0004)
fit <- gam(y~s(x),data=as.data.frame(l_yx),family=binomial)
And I want to plot it so that probability is on the Y axis and values are
on the X axis (i.e. I don't want log
2010 Mar 04
2
which coefficients for a gam(mgcv) model equation?
Dear users,
I am trying to show the equation (including coefficients from the model
estimates) for a gam model but do not understand how to.
Slide 7 from one of the authors presentations (gam-theory.pdf URL:
http://people.bath.ac.uk/sw283/mgcv/) shows a general equation
log{E(yi )} = ?+ ?xi + f (zi ) .
What I would like to do is put my model coefficients and present the
equation used. I am an
2009 Oct 01
2
GAM question
Hello evyrone,
I would be grateful if you could help me in (I hope) simple problem.
I fit a gam model (from mgcv package) with several smooth functions .
I don't know how to extract values of just one smooth function. Can you
please help me in this?
Kind regards,
Daniel Rabczenko
2012 Nov 29
1
[mgcv][gam] Manually defining my own knots?
Dear List,
I'm using GAMs in a multiple imputation project, and I want to be able
to combine the parameter estimates and covariance matrices from each
completed dataset's fitted model in the end. In order to do this, I
need the knots to be uniform for each model with partially-imputed
data. I want to specify these knots based on the quantiles of the
unique values of the non-missing
2004 Dec 01
2
step.gam
Dear R-users:
Im trying (using gam package) to develop a stepwise analysis. My gam
object contains five pedictor variables (a,b,c,d,e,f). I define the
step.gam:
step.gam(gamobject, scope=list("a"= ~s(a,4), "b"= ~s(b,4), "c"= ~s(c,4),
"d"= ~s(d,4), "e"= ~s(e,4), "f"= ~s(f,4)))
However, the result shows a formula containing the whole
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
2007 Jun 22
1
two basic question regarding model selection in GAM
Qusetion #1
*********
Model selection in GAM can be done by using:
1. step.gam {gam} : A directional stepwise search
2. gam {mgcv} : Smoothness estimation using GCV or UBRE/AIC criterion
Suppose my model starts with a additive model (linear part + spline part).
Using gam() {mgcv} i got estimated degrees of freedom(edf) for the smoothing
splines. Now I want to use the functional form of my model
2007 Oct 05
2
question about predict.gam
I'm fitting a Poisson gam model, say
model<-gam(a65tm~as.factor(day.week
)+as.factor(week)+offset(log(pop65))+s(time,k=10,bs="cr",fx=FALSE,by=NA,m=1),sp=c(
0.001),data=dati1,family=poisson)
Currently I've difficulties in obtaining right predictions by using
gam.predict function with MGCV package in R version 2.2.1 (see below my
syntax).
2008 Jun 11
1
mgcv::gam error message for predict.gam
Sometimes, for specific models, I get this error from predict.gam in library
mgcv:
Error in complete.cases(object) : negative length vectors are not allowed
Here's an example:
model.calibrate <-
gam(meansalesw ~ s(tscore,bs="cs",k=4),
data=toplot,
weights=weight,
gam.method="perf.magic")
> test <- predict(model.calibrate,newdata)
Error in
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,
2013 Jul 08
1
error in "predict.gam" used with "bam"
Hello everyone.
I am doing a logistic gam (package mgcv) on a pretty large dataframe
(130.000 cases with 100 variables).
Because of that, the gam is fitted on a random subset of 10000. Now when I
want to predict the values for the rest of the data, I get the following
error:
> gam.basis_alleakti.1.pr=predict(gam.basis_alleakti.1,
+
2008 May 06
1
mgcv::gam shrinkage of smooths
In Dr. Wood's book on GAM, he suggests in section 4.1.6 that it might be
useful to shrink a single smooth by adding S=S+epsilon*I to the penalty
matrix S. The context was the need to be able to shrink the term to zero if
appropriate. I'd like to do this in order to shrink the coefficients towards
zero (irrespective of the penalty for "wiggliness") - but not necessarily
all the
2010 Jun 27
1
mgcv out of memory
Hello, I am trying to update the mgcv package on my Linux box and I keep
getting an "Out of memory!" error. Does anyone know of a fix for this?
Below is a snippet of the message that I keep getting: Thank you. Geoff
** R
** inst
** preparing package for lazy loading
** help
*** installing help indices
>>> Building/Updating help pages for package 'mgcv'
Formats:
2012 Aug 14
1
Random effects in gam (mgcv 1.7-19)
Hi,
I am using the gam function in the mgcv package, I have random effects in
my model (bs="re") this has worked fine, but after I updated the mgcv
package to version 1.7-19 I recive an error message when I run the model.
>
fit1<-gam(IV~s(RUTE,bs="re")+s(T13)+s(H40)+factor(AAR)+s(V3)+s(G1)+s(H1)+s(V1)+factor(LEDD),data=data5,method="ML")
> summary.gam(fit1)
2007 Oct 04
1
Convergence problem in gam(mgcv)
Dear all,
I'm trying to fit a pure additive model of the following formula :
fit <- gam(y~x1+te(x2, x3, bs="cr"))
,with the smoothing parameter estimation method "magic"(default).
Regarding this, I have two questions :
Question 1 :
In some cases the value of "mgcv.conv$fully.converged" becomes
"FALSE", which tells me that the method stopped with a
2012 Jul 23
1
mgcv: Extract random effects from gam model
Hi everyone,
I can't figure out how to extract by-factor random effect adjustments from a
gam model (mgcv package).
Example (from ?gam.vcomp):
library(mgcv)
set.seed(3)
dat <- gamSim(1,n=400,dist="normal",scale=2)
a <- factor(sample(1:10,400,replace=TRUE))
b <- factor(sample(1:7,400,replace=TRUE))
Xa <- model.matrix(~a-1) ## random main effects
Xb <-
2012 Feb 03
1
GAM (mgcv) warning: matrix not positive definite
Dear list,
I fitted the same GAM model using directly the function gam(mgcv) ... then
as a parameter of another function that capture the warnings messages (see
below).
In the first case, there is no warning message printed, but in the last
one, the function find two warning messages stating "matrix not positive
definite"
So my question is: Do I have to worry about those warnings and
2006 Jun 18
1
GAM selection error msgs (mgcv & gam packages)
Hi all,
My question concerns 2 error messages; one in the gam package and one in
the mgcv package (see below). I have read help files and Chambers and
Hastie book but am failing to understand how I can solve this problem.
Could you please tell me what I must adjust so that the command does not
generate error message?
I am trying to achieve model selection for a GAM which is required for
2010 Aug 04
2
more questions on gam/gamm(mgcv)...
Hi R-users,
I'm using R 2.11.1, mgcv 1.6-2 to fit a generalized additive mixed model.
I'm new to this package...and just got more and more problems...
1. Can I include correlation and/or random effect into gam( ) also? or only
gamm( ) could be used?
2. I want to estimate the smoothing function s(x) under each level of
treatment. i.e. different s(x) in each level of treatment. shall I