Displaying 20 results from an estimated 6000 matches similar to: "R equivalent to Matlab spline(x,y,xx)"
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
1998 May 25
2
RFC: spline / splinefun (etc) amalgamation
At present R has separate functions "spline" and "splinefun". The first
of these carries out spline interpolation of a data set and returns the
interpolated values; the second returns the interpolating function itself
(approx and approxfun are similar).
I would like to combine these into a single function "spline" with
an (optional) argument which determines which
2008 Jun 02
0
Missing "spline_coef" DLL and Rob Hyndmans monotonic interpolator
Hello R help
I have been trying to use Rob Hyndman's monotonically increasing spline
function. But like another user or two seem have a problem with a
missing DLL (namely "spline_coef"). None of the previous help postings
seemed to have any solutions to this problem. As per a Ripley
suggestion I have deleted all previous versions of R and reinstalled R
2.7.0 and the problem
2010 Feb 15
1
Non-monotonic spline using splinefun(method = "monoH.FC")
Hi,
In my version of R, the stats package splinefun code for fitting a
Fritsch and Carlson monotonic spline does not appear to guarantee a
monotonic result. If two adjoining sections both have over/undershoot
the way the resulting adjustment of alpha and beta is performed can give
modified values which still do not satisfy the required constraints. I
do not think this is due to finite precision
2010 Mar 06
1
Possible to use array of spline functions for storing data?
Dear listeRs;
I am hoping to provide myself the ability to interpolate mortality
estimates within intervals for a range of conditions and ages. I have
four mortality tables derived from the Society of Actuaries 2001 VBT
tables that contains interval mortality rates by starting age and year
of duration. I would like to flexibly interpolate using a large set
(~4MM) of ages and conditions
2011 Oct 18
0
rls() fails on function calling spline()
Hello everybody
I want to use rls() on a multi-dimensional function, where parts of it are modeled using a spline.
I tried to condense my problem into the following code example,
which tries to fit the y-values of a spline interpolation:
---------------------------------------------------------------------------
rm(list=ls(all=TRUE))
x<-c(1,2,3,4,5,6,7,8,9)
y<-x^2
2007 Feb 13
4
matlab style plotting in R
Hello
I was wondering how I can achieve matlab style plotting in R,
in the sense that matlab allows you to plot multiple sets of variables
within the same
x-y axes. plot in R does not seem to cater for this. I tried 'overplot' from
the gplots package but this assumes different y axes for the variables.
any suggestions would be very appreciated
Maria
[[alternative HTML version
2006 Mar 17
1
Derivative of a splinefun function.
Is there a way of calculating the derivative of a function returned
by splinefun()? Such a function is a cubic spline, whence it has a
calculable derivative, but is there a (simple) way of getting at it?
One workaround that I have thought of is to take a fine grid of
points, evaluate the function returned by splinefun() at these
points, put an interpolating spline through these points using
2012 Dec 01
3
cubic spline
Hallo,
I'm facing a problem and I would really appreciate your support.
I have to translate some Matalb code in R that I don't know very well but I
would like to.
I have to interpolate 5 point with a cubic spline function and then I expect
my function returns the Y value as output a specific X value inside the
evaluation range. Let's suppose that:
1- *X = [-10, -5, 0, 5, 10]*
2
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?
2009 Jan 08
2
interpolation to abscissa
Readers,
I have looked at various documents hosted on the web site; I couldn't
find anything on interpolation. So I started r and accessed the help
(help.start()). (by the way is it possible to configure r to open help
in opera instead of firefox?) Initially I read the help for the akima
package but couldn't understand it. Next I tried the asplines package
help.
I tried to copy the
2008 Oct 07
0
splinefun gives incorrect derivs when extrapolating to the (PR#13138)
--MP_/Rxf/JAvsQx5JLkhZFc9Jmn4
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
G'day Greg,
On Mon, 6 Oct 2008 19:50:13 +0200 (CEST)
Greg.Snow at imail.org wrote:
> This is a low priority bug that has been around for a while, but I
> came across it again while alpha testing 2.8.
Indeed, that bug must have been around since
2005 Jul 24
1
Buglet in src/appl/splines.c (PR#8030)
--AZaLVt6Pw+
Content-Type: text/plain; charset=us-ascii
Content-Description: message body text
Content-Transfer-Encoding: 7bit
Dear all,
I was looking at "splinefun" and the underlying C code and believe
that there is a memory access error in the C routine "spline_eval".
Specifically, on line 368 and following the following code appears:
if(ul < x[i] || x[i+1] < ul)
2008 Oct 07
0
splinefun gives incorrect derivs when extrapolating to the (PR#13139)
--MP_/kvy20nVajVG/n.8m=_ZjLAX
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
On Tue, 7 Oct 2008 19:31:03 +0800
Berwin A Turlach <berwin at maths.uwa.edu.au> wrote:
> The attached patch (against the current SVN version of R) implements
> the latter strategy. With this patch applied, "make check
> FORCE=FORCE" passes
2005 May 02
2
Restricted cubic spline function ERROR?: glm(Y~rcs(x,5))
Dear all,
Is the restricted cubic spline function working properly in the glm model?
We used glm(y~rcs(x,5), family=binomial) but it seems that for some
theoretical reasons the rcs, restricted cubic spline function can not be
fitted by a glm function. Is this correct?
Regards,
Jan
((Originally, we used lrm(y~ rcs(x,5)) but we couldn't find how to derive
the AIC value of the fitted model.
2001 May 14
0
followup: lookup function for density(...) objects
Thanks to Ross Ihaka and Bob Wheeler for responding to my earlier question. I
looked into the Johnson system functions in SuppDists package. For now, I want
to stick with the density(...) estimator, and so still need the variate lookup
function.
As per Ross' suggestion, I just did a numerical integration on the density
object and used approxfun/splinefun to "lookup" the variate
2007 Nov 14
1
problems with splinefun()
I am working with the function: splinefun() ...
When plugging in the variables, I get the function program as if
though having only entered '"splinefun". only way to get the values
is by
spline(xxx,yyy, n=length(xxx)/10, ties = mean)$x and spline(xxx,yyy,
n=length(xxx)/10, ties = mean)$y.
I'm just wondering if there is something wrong with the package or if
I'm doing
1997 Apr 30
1
R-beta: Re: S Compatibility
Bill Venables writes:
> Are the scoping differences between R and S set out precisely and
> definitively somewhere? This would be useful.
In the source code perhaps? :-)
You can find a pretty precise description in the article Robert and I
did in JCGS.
Actually its pretty simple. Functions have access to the variables
which were in effect when the function was defined.
f <-
2011 Nov 22
0
plotting output from LME with natural cubic spline
I have used LME to fit a mixed effects model on my data. The data has
274 subjects with 1 to 6 observations per subject. Time is not linearly
associated with the outcome, so I used ns to fit a natural cubic spline
with 3 auto knots. Subject and the natural cubic time of spline are both
treated as random effects. This model has run without any problem, but
now I would like to plot trajectories for
2010 Mar 12
1
Usage of apply function with two matrices
Hello,
I am struggling to overcome following problem:
I have matrix Vf and matrix V, which both have 3 columns and I want to
create a spline function basing on coordinates from this matrices (more
precisely coordinates of function nr 1: x are taken from Vf[,1] and y are
taken from V[,1] respectively), because function apply() base on 1 argument
I made it in this way: