Displaying 20 results from an estimated 10000 matches similar to: "mgcv with discrete covariates, interaction term"
2011 Feb 16
1
retrieving partial residuals of gam fit (mgcv)
Dear list,
does anybody know whether there is a way to easily retrieve the so called "partial residuals" of a gam fit with package mgcv? The partial residuals are the residuals you would get if you would "leave out" a particular predictor and are the dots in the plots created by
plot(gam.object,residuals=TRUE)
residuals.gam() gives me whole model residuals and
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)
2012 Jun 11
0
gamm (mgcv) interaction with linear term
Hello,
I am trying to fit a gamm (package mgcv) model with a smooth term, a linear term, and an interaction between the two. The reason I am using gamm rather than gam is that there are repeated measures in time (which is the smooth term x1), so I am including an AR1 autocorrelation term. The model I have so far ended up with is of the type
gamm(y ~ s(x1) + s(x1, by=x2), correlation =
2011 Jun 27
1
group interaction in a varying coeff. model (mgcv)
Dear UseRs,
I built varying coefficient models (in mgcv) for two groups separately, with one explanatory and one moderator variable (see the example below).
# -------
# Example:
# ------
# generate moderator variable (can the same for both groups)
modvar <- c(1:1000)
# generate group1 values
x1 <- rnorm(1000)
y1 <- scale(cbind(1,poly(modvar,2))%*%c(1,2,1)*x1 +
rnorm(1000,0,0.3))
#
2012 Aug 24
3
mgcv package, problems with NAs in gam
Hi there,
I'm using presence-absence data in a gam (i.e. 0 or 1 as values)
I am trying to run a gam with 'dummy covariates' i.e. 1~1
unfortunately my model:
*
model<-gam(1~1, data=bats, family=negbin)*
keeps putting out:
*
Error in gam(1 ~ 1, data = bats, family = negbin) :
Not enough (non-NA) data to do anything meaningful*
Is there a specific reason it would do this? I have
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
2018 Jan 17
1
mgcv::gam is it possible to have a 'simple' product of 1-d smooths?
I am trying to test out several mgcv::gam models in a scalar-on-function regression analysis.
The following is the 'hierarchy' of models I would like to test:
(1) Y_i = a + integral[ X_i(t)*Beta(t) dt ]
(2) Y_i = a + integral[ F{X_i(t)}*Beta(t) dt ]
(3) Y_i = a + integral[ F{X_i(t),t} dt ]
equivalents for discrete data might be:
1) Y_i = a + sum_t[ L_t * X_it * Beta_t ]
(2) Y_i
2013 Jun 17
1
Can you use two offsets in gam (mgcv)?
Hello,
I have been trying to find out whether it is possible to use more than one
offset in a gam (in mgcv).
The reason I would like to do this is to 1) account for area surveyed in a
Poisson model of sightings of porpoises within defined grid cells (each cell
has a slightly different area) and 2) account for detection probability
within each grid cell (some grid cells are further away from the
2009 May 18
1
Predicting complicated GAMMs on response scale
Hi,
I am using GAMMs to show a relationship of temperature differential over
time with a model that looks like this:-
gamm(Diff~s(DaysPT)+AirToC,method="REML")
where DaysPT is time in days since injury and Diff is repeat measures of
temperature differentials with regards to injury sites compared to
non-injured sites in individuals over the course of 0-24 days. I use the
following
2007 Aug 14
1
weights in GAMs (package mgcv)
Dear list,
I?m using the ?mgcv? package to fit some GAMs. Some of my covariates are
derived quantities and have an associated standard error, so I would
like to incorporate this uncertainty into the GAM estimation process.
Ideally, during the estimation process less importance would be given to
observations whose covariates have high standard errors.
The gam() function in the ?mgcv? package
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:
2011 Jun 07
2
gam() (in mgcv) with multiple interactions
Hi! I'm learning mgcv, and reading Simon Wood's book on GAMs, as recommended to me earlier by some folks on this list. I've run into a question to which I can't find the answer in his book, so I'm hoping somebody here knows.
My outcome variable is binary, so I'm doing a binomial fit with gam(). I have five independent variables, all continuous, all uniformly
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,
2007 Apr 08
1
Relative GCV - poisson and negbin GAMs (mgcv)
I am using gam in mgcv (1.3-22) and trying to use gcv to help with model selection. However, I'm a little confused by the process of assessing GCV scores based on their magnitude (or on relative changes in magnitude).
Differences in GCV scores often seem "obvious" with my poisson gams but with negative binomial, the decision seems less clear.
My data represent a similar pattern as
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
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)
2007 Jun 11
1
Error using mgcv package
Hi all,
I need some solution in the following problem. The following error appears
when i use "mgcv" package for implementing GAM. But the same formula works
fine in "gam" package.
> model.gam <- gam(formula = RES ~
> CAT01+s(NUM01,5)+CAT02+CAT03+s(NUM02,5)+CAT04+
+ CAT05+s(NUM03,5)+CAT06+CAT07+s(NUM04,5)+CAT08+s(NUM05,5)+CAT09+
+
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
2012 Jul 30
2
mgcv 1.7-19, vis.gam(): "invalid 'z' limits'
Hi everyone,
I ran a binomial GAM consisting of a tensor product of two continuous
variables, a continuous parametric term and crossed random intercepts on a
data set with 13,042 rows. When trying to plot the tensor product with
vis.gam(), I get the following error message:
Error in persp.default(m1, m2, z, col = col, zlim = c(min.z, max.z), xlab =
view[1], :
invalid 'z' limits
In
2009 Mar 24
2
help: what are the basis functions in {mgcv}: gam?
I am writing my thesis with the function gam(), with the package {mgcv}.
My command is: gam(y~s(x1,bs="cr")+s(x2, bs="cr")).
I need help to know what are the default basis funcitons for gam. I have not
found any detailed reference for this.
Can anyone help me with this??
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