Displaying 20 results from an estimated 11000 matches similar to: "Curve fitting, probably splines"
2005 Mar 30
6
French Curve
Dear R experts,
Did someone implemented French Curve yet? Or can anyone point me some
papers that I can follow to implement it?
thanks in advance for your help.
Paul
2012 Jul 11
2
Modifying the design matrix X in GAMS to suit data assimilation
I have a data assimilation problem that might be amenable to the use of GAMS, but I am not sure how feasible it is to implement. I was told the R mailing list was a great resource.
My observations are spatiotemporal salinity in the San Francisco Bay at a number of instruments over a few days. The thing that I want to fit is the initial condition for a salt transport model at the beginning of this
2012 May 17
1
oldlogspline probabilities
I using oldlogspline (from logspline package) to model data distributions, and having a problem.
My data are search area sizes. They are based on circular search radii from random points to the nearest edge of the nearest grass tussock. Search area sizes are distributed from 0 (the random point intercepts a tussock) and upwards (as points are further from any tussocks). The density of all my
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
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
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 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
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
2009 Jan 16
2
Smooth periodic splines
Hello group!
Is there a package that allows to fit smooth *periodic* splines to
data? I'm interested in a function which combines the functionality of
smooth.spline and splines::periodicSpline.
Thanks,
Andrey
2010 Apr 02
4
Derivative of a smooth function
Dear All,
I've been?searching for?appropriate codes to compute the rate of change and the curvature?of ?nonparametric regression model whish was denoted by a smooth function?but?unfortunately?don't manage to?do?it. I presume that such characteristics from a smooth curve can be determined by the first and second derivative operators.
The following are the example of fitting a
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:
>
2011 Mar 14
1
Help- Fitting a Thin Plate Spline
Hi Everyone,
I'm a pretty useless r-er but have data that SPSS etc doesn't like. I've
managed to do GLMs for my data, but now need to fit a thin plate spline for
my data (arcsine.success~date.num:clutch.size)
If anyone has a bit of spare time and could come up with a bit of code I'd
be very grateful- I just don't get R language!
Thanks
Rach
--
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2013 Apr 23
1
GAM Penalised Splines - Intercept
Hey all,
I'm using the gam() function inside the mgcv package to fit a penalised spline to some data. However, I don't quite understand what exactly the intercept it includes by default is / how to interpret it.
Ideally I'd like to understand what the intercept is in terms of the B-Spline and/or truncated power series basis representation.
Thanks!
2010 May 11
1
Splines under tension
Does anyone know if R has a function for splines under tension. I know there
are numerous packages for spline interpolation within R i just can't find
one that lets you determine the tension factor.
Any help would be much appreciated!
Sam
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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
2006 Mar 16
1
running median and smoothing splines for robust surface f itting
loess() should be able to do robust 2D smoothing.
There's no natural ordering in 2D, so defining running medians can be
tricky. I seem to recall Prof. Koenker talked about some robust 2D
smoothing method at useR! 2004, but can't remember if it's available in some
packages.
Andy
From: Vladislav Petyuk
>
> Hi,
> Are there any multidimenstional versions of runmed() and
>
2003 Apr 07
3
spline with multiple predictor vars?
Hi, is there a way in R to generate a polynomial spline with multiple predictor
variables? I have one response and two predictors and I'm trying to fit a
spline model for this...
Please cc me on the reply..
Thanks,
nirmal
2011 Aug 06
1
How to estimate confidential intervals for the derivatives of cubic smoothing spline
Dear all,
I want to use smooth.spline to construct a cubic smoothing spline and its first
derivative to my data. However, the predict.smooth.spline does not seem to
provide a SE for both the fitted values and their derivatives. How should I
calculate it?
Thank you very much,
Bingzhang
2009 Oct 13
2
How to choose a proper smoothing spline in GAM of mgcv package?
Hi, there,
I have 5 datasets. I would like to choose a basis spline with same knots in
GAM function in order to obtain same basis function for 5 datasets.
Moreover, the basis spline is used to for an interaction of two covarites.
I used "cr" in one covariate, but it can only smooth w.r.t 1 covariate. Can
anyone give me some suggestion about how to choose a proper smoothing spline
2007 Jul 02
1
gam function & time trend splines
I've been doing a simple time-series analysis looking
at the relationship between daily pneumonia
hospitalizations and daily temperature. To mimic some
of the literature, I've been including a time-trend to
try to account for normal cyclical trends in
hospitalization. So I've been using a function that
looks something like this:
gam(pneucount ~ temp_f +