Displaying 20 results from an estimated 3000 matches similar to: "Use estimated non-parametric model for sensitivity analysis"
2009 Aug 06
1
solving system of equations involving non-linearities
Hi,
I would appreciate if someone could help me on track with this problem.
I want to compute some parameters from a system of equations given a number of sample observations. The system looks like this:
sum_i( A+b_i>0 & A+b_i>C+d_i) = x
sum_i( C+d_i>0 & C+d_i>A+b_i) = y
sum_i( exp(E+f_i) * ( A+b_i>0 & A+b_i>C+d_i) = z
A, C, E are free variables while the other
2009 Apr 21
2
Changing the binning of collected data
Dear All,
Apologies if this is too simple for this list.
Let us assume that you have an instrument measuring particle distributions.
The output is a set of counts {n_i} corresponding to a set of average
sizes {d_i}.
The set of {d_i} ranges from d_i_min to d_i_max either linearly of
logarithmically.
There is no access to further detailed information about the
distribution of the measured sizes, but
2007 Apr 16
1
Does the smooth terms in GAM have a functional form?
Hi, all,
Does anyone know how to get the functional form of the smooth terms in GAM? eg. I fit y=a+b*s(x) where s is the smooth function.
After fitting this model with GAM in R, I want to know the form of the s(x). Any suggestion is appreciated.
Thanks,
Jin
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2008 Jul 31
1
clustering and data-mining...
Hi all,
I am doing some experiment studies...
It seems to me that with different combination of 5 parameters, the end
results ultimately converged to two scalars. That's to say, some
combinations of the 5 parameters lead to one end result and some other
combinations of the 5 parameters lead to the other end result (scalar).
I am thinking of this is sort of something like clustering or
2008 Apr 09
1
mgcv::predict.gam lpmatrix for prediction outside of R
This is in regards to the suggested use of type="lpmatrix" in the
documentation for mgcv::predict.gam. Could one not get the same result more
simply by using type="terms" and interpolating each term directly? What is
the advantage of the lpmatrix approach for prediction outside R? Thanks.
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2012 May 23
1
mgcv: How to calculate a confidence interval of a ratio
Dear R-Users,
Dr. Wood replied to a similar topic before where confidence intervals were
for a ratio of two treatments (
https://stat.ethz.ch/pipermail/r-help/2011-June/282190.html). But my
question is more complicated than that one. In my case, log(E(y)) = s(x)
where y is a smooth function of x. What I want is the confidence interval
of a ratio of log[(E(y2))/E(y1)] given two fixed x values of
2008 Oct 01
1
Simon Wood GAMsetup
Dear Simon, Thank you for your quick reply!
I used to perform the GAMsetup in the following manner:
GAMsetup sintax:
x.summer: vector used for construct the spline
knots<-14
N<-length(x.summer)
x<-array(x.summer,dim=c(1,N))
G<-list(m=1,n=N,nsdf=0,df=knots+1,dim=1,s.type=0,by=0,by.exists=FALSE,p.order=0,x=x,n.knots=knots,fit.method="mgcv")
H<-GAMsetup(G)
with the
2010 Aug 05
2
compare gam fits
Hi folks,
I originally tried R-SIG-Mixed-Models for this one
(https://stat.ethz.ch/pipermail/r-sig-mixed-models/2010q3/004170.html),
but I think that the final steps to a solution aren't mixed-model
specific, so I thought I'd ask my final questions here.
I used gamm4 to fit a generalized additive mixed model to data from a
AxBxC design, where A is a random effect (human participants in
2007 Mar 27
1
gam parameter predictions --Sorry for double posting
R-help,
Sorry for posting again the same question (dated 26-03-2007) but
all my mails have been sent to the recycle bin without possibility
of recovering and thus I don't know if anyone has answer my query.
Here is the original message:
I'm applying a gam model (package mgcv) to predict
relative abundances of a fish species.
The covariates are year, month, vessel and statistical
2013 Mar 23
1
Time trends with GAM
Hi all,
I am using GAM to model time trends in a logistic regression. Yet I would
like to extract the the fitted spline from it to add it to another model,
that cannot be fitted in GAM or GAMM.
Thus I have 2 questions:
1) How can I fit a smoother over time so that I force one knot to be at a
particular location while letting the model to find the other knots?
2) how can I extract the matrix
2012 Sep 25
1
REML - quasipoisson
hi
I'm puzzled as to the relation between the REML score computed by gam and
the formula (4) on p.4 here:
http://opus.bath.ac.uk/22707/1/Wood_JRSSB_2011_73_1_3.pdf
I'm ok with this for poisson, or for quasipoisson when phi=1.
However, when phi differs from 1, I'm stuck.
#simulate some data
library(mgcv)
set.seed(1)
x1<-runif(500)
x2<-rnorm(500)
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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2006 Mar 23
1
gam y-axis interpretation
Sorry if this is an obvious question...
I'm estimating a simple binomial generalized additive model using the
gam function in the package mgcv. The model makes sense given my data,
and the predicted values also make sense given what I know about the
data.
However, I'm having trouble interpreting the y-axis of the plot of the
gam object. The y-axis is labeled "s(x,2.52)"
2011 Apr 19
1
Prediction interval with GAM?
Hello,
Is it possible to estimate prediction interval using GAM? I looked through
?gam, ?predict.gam etc and the mgcv.pdf Simon Wood. I found it can
calculate confidence interval but not clear if I can get it to calculate
prediction interval. I read "Inference for GAMs is difficult and somewhat
contentious." in Kuhnert and Venable An Introduction to R, and wondering why
and if that
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 Apr 02
2
How to choose the df when using GAM function?
Dear all,
When using GAM function in R, we need to specify the degree of freedom for the smooth function (i.e. s=(x, df=#)). I am wondering how to choose an appropriate df.
Thanks a lot,
Jin
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North Carolina State University
USA
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2007 Apr 19
5
Polycom IP 501 is displaying wrong time
Hi,
This is Chandra. I have Polycom IP 501 phone. Its showing wrong time on the display screen. How can I set the "New York" time? What value I have to give to GMT offset value?
Look forward to your response. Thank you.
Regards,
Chandra.
---------------------------------
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Check outnew cars at Yahoo! Autos.
2007 Apr 13
1
How can i add multiple callerids to an inbound route?
Hi,
I have configured the below things:
Extensions
Trunk
Outbound route
Inbound route
IVR
Ring group
If anybody call to my DID number, my IVR is responded. After that, if he press 1, then Ring group will be activated. All are working fine.
My Problem:
I want to avoid IVR for some phone numbers depends on their called IDs. If my common users will call to my DID
2007 Apr 17
3
DomU Kernel Mapping
Where is the code that maps the kernel of a DomU into memory?
i.e, when you do a xm create <config file>
what code is called to actually map the kernel into memory?
Is it a python script or is it re-directed to Dom0 to do?
Thanks.
-Brian
---------------------------------
Ahhh...imagining that irresistible "new car" smell?
Check outnew cars at Yahoo! Autos.
2007 Apr 17
3
DomU Kernel Mapping
Where is the code that maps the kernel of a DomU into memory?
i.e, when you do a xm create <config file>
what code is called to actually map the kernel into memory?
Is it a python script or is it re-directed to Dom0 to do?
Thanks.
-Brian
---------------------------------
Ahhh...imagining that irresistible "new car" smell?
Check outnew cars at Yahoo! Autos.