Displaying 20 results from an estimated 20000 matches similar to: "2d approx"
2011 Mar 28
2
mgcv gam predict problem
Hello
I'm using function gam from package mgcv to fit splines. ?When I try
to make a prediction slightly beyond the original 'x' range, I get
this error:
> A = runif(50,1,149)
> B = sqrt(A) + rnorm(50)
> range(A)
[1] 3.289136 145.342961
>
>
> fit1 = gam(B ~ s(A, bs="ps"), outer.ok=TRUE)
> predict(fit1, newdata=data.frame(A=149.9), outer.ok=TRUE)
Error
2010 Dec 08
1
I want to get smoothed splines by using the class gam
Hi all,
I try to interpolate a data set in the form:
time Erg
0.000000 48.650000
1.500000 56.080000
3.000000 38.330000
4.500000 49.650000
6.000000 61.390000
7.500000 51.250000
9.000000 50.450000
10.500000 55.110000
12.000000 61.120000
18.000000 61.260000
24.000000 62.670000
36.000000 63.670000
48.000000 74.880000
I want to get smoothed splines by using the class gam
The first way I tried , was
2011 Jun 24
2
mgcv:gamm: predict to reflect random s() effects?
Dear useRs,
I am using the gamm function in the mgcv package to model a smooth relationship between a covariate and my dependent variable, while allowing for quantification of the subjectwise variability in the smooths. What I would like to do is to make subjectwise predictions for plotting purposes which account for the random smooth components of the fit.
An example. (sessionInfo() is at
2011 Sep 20
2
Multivariate spline regression and predicted values
Hello,
I am trying to estimate a multivariate regression of Y on X with
regression splines. Y is (nx1), and X is (nxd), with d>1. I assume the
data is generated by some unknown regression function f(X), as in Y =
f(X) + u, where u is some well-behaved regression error. I want to
estimate f(X) via regression splines (tensor product splines). Then, I
want to get the predicted values for some new
2007 Feb 13
1
Missing variable in new dataframe for prediction
Hi,
I'm using a loop to evaluate several models by taking adjacent variables from my dataframe.
When i try to get predictions for new values, i get an error message about a missing variable in my new dataframe.
Below is an example adapted from ?gam in mgcv package
library(mgcv)
set.seed(0)
n<-400
sig<-2
x0 <- runif(n, 0, 1)
x1 <- runif(n, 0, 1)
x2 <- runif(n, 0, 1)
x3 <-
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
2010 Dec 14
2
Use generalised additive model to plot curve
Readers,
I have been reading 'the r book' by Crawley and think that the
generalised additive model is appropriate for this problem. The
package 'gam' was installed using the command (as root)
install.package("gam")
...
library(gam)
> library(gam)
Loading required package: splines
Loading required package: akima
> library(mgcv)
This is mgcv 1.3-25
Attaching
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,
+
2003 Jan 09
2
GAM with Thin plate splines
Hello, I'm a student at the University of Klagenfurt / Austria and I
need some help !
I have to predict 24 daily load-values.
Therefor I got a dataset with following colums:
24 past daily load-values
6 past daily temperature-values
My goal is to find a model (GAM with thin plate splines) in R.
I found the function "gam" in the R-library "mgcv", but it just fits
2009 Feb 25
1
monotonic GAM with more than one term
Hi,
Does anyone know how to fit a GAM where one or more smooth terms are
constrained to be monotonic, in the presence of "by" variables or
other terms? I looked at the example in ?pcls but so far have not been
able to adapt it to the case where there is more than one predictor.
For example,
require(mgcv)
set.seed(0)
n<-100
# Generate data from a monotonic truth.
2005 Mar 24
1
Prediction using GAM
Recently I was using GAM and couldn't help noticing
the following incoherence in prediction:
> data(gam.data)
> data(gam.newdata)
> gam.object <- gam(y ~ s(x,6) + z, data=gam.data)
> predict(gam.object)[1]
1
0.8017407
>
predict(gam.object,data.frame(x=gam.data$x[1],z=gam.data$z[1]))
1
0.1668452
I would expect that using two types of predict
arguments
2010 Jun 04
1
package mgcv inconsistency in help files? cyclic P-spline "cs" not cyclic?
Dear all,
I'm a bit stunned by the behaviour of a gam model using cyclic
P-spline smoothers. I cannot provide the data, as I have about 61.000
observations from a time series.
I use the following model :
testgam <- gam(NO~s(x)+s(y,bs="cs")+s(DD,bs="cs")+s(TT),data=Final)
The problem lies with the cyclic smoother I use for seasonal trends.
The variable Final$y is a
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 Oct 10
2
GAM without intercept
Hi everybody,
I am trying to fit a GAM model without intercept using library mgcv.
However, the result has nothing to do with the observed data. In fact
the predicted points are far from the predicted points obtained from the
model with intercept. For example:
#First I generate some simulated data:
library(mgcv)
x<-seq(0,10,length=100)
y<-x^2+rnorm(100)
#then I fit a gam model with
2011 Jul 19
2
Incorrect degrees of freedom for splines using GAMM4?
Hello,
I'm running mixed models in GAMM4 with 2 (non-nested) random intercepts and
I want to include a spline term for one of my exposure variables. However,
when I include a spline term, I always get reported degrees of freedom of
less than 1, even when I know that my spline is using more than 1 degree of
freedom. For example, here is the code for my model:
>
2005 Nov 23
1
1st derivative {mgcv} gam smooth
Dear R-hep,
I'm trying to get the first derivative of a smooth from a gam
model like:
model<-gam(y~s(x,bs="cr", k=5)+z) and need the derivative: ds(x)/dx. Since
coef(model) give me all the parameters, including the parameters of the
basis, I just need the 1st derivative of the basis s(x).1, s(x).2, s(x).3,
s(x).4. If the basis were generated with the function
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
2004 Sep 27
2
passing formula arg to mgcv::gam
Hi,
I have a function, callGam, that fits a gam model to a subset of a dataframe. The argument to callGam is a formula, the subset is determined inside the function itself. My na??ve approach generates and error, see below. I guess this is because 'idx' is loocked up in the environment of 'formula', but I am too ignorant about environments to be able to tell for sure. Could
2003 Jun 07
0
problem with predict() for gam() models
I run the following code in R 1.6.2 on Windows:
xxx <- rnorm(100)
yyy <- .5 * rnorm(100) + sqrt(1-.5^2) * rnorm(100)
ord <- order(xxx)
xxx <- xxx[ord] # for
yyy <- yyy[ord] # convenience in reading printout
rm(ord)
reg.gam <- gam(yyy ~ s(xxx, k=8))
f <- function(x, reg.gam, target.y) {
cat("inside f() called by optimize():\n")
cat("arg x=", x,
2009 Nov 21
1
3-D Plotting of predictions from GAM/GAMM object
Hello all,
Thank you for the previous assistance I received from this listserve!
My current question is: How can I create an appropriate matrix of
values from a GAM (actually a GAMM) to make a 3-D plot? This model is
fit as a tensor product spline of two predictors and I have used it to
make specific predictions by calling: