similar to: Spline

Displaying 20 results from an estimated 10000 matches similar to: "Spline"

2009 Oct 12
3
help with the use of mtext to create main title over multiple plots
I'm trying to use mtext to create a main title over multiple plots. Below is a simple self-contained example and my sessionInfo (I should note I've also tried this with R-2.8.1 with the same results). When I execute the code chunk below, I get the plots, but no title. I've tried this using the screen driver, pdf, and postscript. I've used different sizes of paper. I suspect I am
2009 Dec 19
1
model matrix with a spline
Hi all I want to get the design matrix for a model, evaluated at a single value. For example, if I pass in a data frame with a=2, b=2, y=3, and my model is y ~ a+b+a:b, then I would like to get the values 3, 2, 2, 4 out. I can do this with: tmp <- model.matrix(fit, data=mydata) or tmp <- predict(fit, newdata=mydata, type="terms") However, if the fit had a smoothing spline
2003 Aug 14
2
Using spline parameters to generate data
# I need to generate some data. I'm modeling some time series that follow a # negative exponential decay (mostly). I have 20 samples that can easily be fit with cubic splines. # What I want to do is generate many thousands of similar samples using the parameters from the splines # For instance one data sample looks not unlike this: foo.curve <- 1 * exp(-0.01 * 1:500) + 0.5
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
2013 Mar 06
1
Constrained cubic smoothing spline
Hello everone,            Anyone who knows how to force a cubic smoothing spline to pass through a particular point?            I found on website  someone said that we can use "cobs package" to force the spline pass through certain points or impose shape           constraints (increasing, decreasing). However,  this package is using  B-spline and can only do linear and quadratic
2000 Sep 04
2
bug in spline()? (PR#653)
BUG IN SPLINE()? Version R-1.0.1, system i486,linux If the spline(x,y,method="natural") function is given values outside the range of the data, it does not give a warning. Moreover, the extrapolated value reported is not the ordinate of the natural spline defined by (x,y). Example. Let x <- c(2,5,8,10) and y <- c(1.2266,-1.7606,-0.5051,1.0390). Then interpolate/extrapolate with
2012 Mar 12
1
Fwd: Re[2]: B-spline/smooth.basis derivative matrices
--- On Mon, 3/12/12, aleksandr shfets <a_shfets at mail.ru> wrote: > From: aleksandr shfets <a_shfets at mail.ru> > Subject: Fwd: Re[2]: [R] B-spline/smooth.basis derivative matrices > To: "Vassily Shvets" <shv736 at yahoo.com> > Received: Monday, March 12, 2012, 5:15 PM > > > > -------- ???????????? ????????? > -------- > ?? ????:
2006 Jul 31
1
questions regarding spline functions
Greetings, A couple general questions regarding the use of splines to interpolate depth profile data. Here is an example of a set of depths, with associated attributes for a given soil profile, along with a function for calculating midpoints from a set of soil horizon boundaries: #calculate midpoints: mid <- function(x) { for( i in 1:length(x)) { if( i > 1) { a[i] = (x[i] -
2001 Dec 05
4
Questions about piecewise spline fitting
Hi All, I want to fit a piecewise spline of degree 1, i.e. a spline consisting of a straight line over each piece. I downloaded the R package pspline, then I have following questions: 1. in the program, the degree of the spline is specified by 2*norder-1. Why do they adopt such scheme that we can only fit a spline with odd degree? 2. norder cannot be set to 1. Is there any specific reason
2008 Jul 17
1
smooth.spline
I like what smooth.spline does but I am unclear on the output. I can see from the documentation that there are fit.coef but I am unclear what those coeficients are applied to.With spline I understand the "noraml" coefficients applied to a cubic polynomial. But these coefficients I am not sure how to interpret. If I had a description of the algorithm maybe I could figure it out but as it
2008 Dec 16
1
Application b-spline basis for polynomial splines
Hai everbody,  Is there anyone have simple application b-spline in r language? I need it for make me understanding about b-spline for polynomial spline. thank u Arif  New Email addresses available on Yahoo! Get the Email name you&#39;ve always wanted on the new @ymail and @rocketmail. Hurry before someone else does! [[alternative HTML version deleted]]
2010 Apr 09
1
How to get the penalty matrix for natural cubic spline?
Hi, all I am trying to get the basis matrix and penalty matrix for natural cubic splines. In the "splines" package of R,"ns" can generate the B-spline basis matrix for a natural cubic spline. How can I get the basis matrix and penalty matrix for natural cubic spline. Thanks a lot! Lee [[alternative HTML version deleted]]
2001 Apr 26
3
Installing smooth.spline command
Hello I have installed R-0.90.1 on my Linux (Redhat 6.2) machine, unfortunately I am not able to use a number of commands like e.g. smooth.spline and predict.smooth.spline. The error messages being given by is: Error: Object "smooth.spline" not found With the command library() I have checked or the libraries for the smoothing functions are there, as shown below. -------- >
2012 Feb 24
1
B-spline/smooth.basis derivative matrices
Hello, I've noticed that SPLUS seems to have a function for evaluating derivative matrices of splines. I've found the R function that evaluates matrices from 'smooth.spline'; maybe someone has written something to do the same with smooth.basis? regards, s
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
1998 Apr 07
3
R-beta: spline problems(?)
Hi, I am a total beginner with this whole thing so please have patience! I am trying to run an S-plus program with a certain line: spline(1:nrow(y), y[,1],n=100); This crashes with: Error: NAs in foreign function call (arg 8) Apparently, this is caused by the last command of spline: u <- seq(xmin, xmax, length.out = n) .C("spline_eval", z$method, length(u), x = u, y =
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
2012 Feb 24
1
evaluating derivative matrices of spline functions
Hello, I've noticed that SPLUS has a function for evaluating the derivative matrices of splines. I've also noticed that there's a function in R for evaluating matrices from smooth.spline; maybe someone knows if something has been written to evaluate matrices from 'smooth.basis'? regards, s
2009 Mar 31
2
How to generate natural cubic spline in R?
Suppose I have two var x and y,now I want to fits a natural cubic spline in x to y,at the same time create new var containing the smoothed values of y. How can I get it?
2002 Feb 20
2
How to get the penalized log likelihood from smooth.spline()?
I use smooth.spline(x, y) in package modreg and I would like to get value of penalized log likelihood and preferable also its two parts. To make clear what I am asking for (and make sure that I am asking for the right thing) I clarify my problem trying to use the same notation as in help(smooth.spline): I want to find the natural cubic spline f(x) such that L(f) = \sum_{k=1}{n} w[k](y[k] -