similar to: Splines?

Displaying 20 results from an estimated 4000 matches similar to: "Splines?"

2013 Mar 20
0
unexpected local minima/maxima with surf.gls
Hi there, I use the surf.gls() function to fit a variable measured over a surface. When I plot the predicted surface, there are local minima/maxima in almost every coordinate where data were measured, which seems aberrant. For instance: ?? x <- c(343,293,343,243,293,343,443,543,593,243,293,343,393,443,493,543,593,143,193,243,293,343,393,443,
2008 Dec 09
1
package "wmtsa": wavCWTPeaks error (PR#13381)
Full_Name: Maura Monville Version: 2.8 OS: Mac OS/X 10.5 Submission from: (NULL) (87.4.122.234) Here is the code that causes wavCWTPeaks error aats <- create.signalSeries(aa, pos=list(from=0.0, by=0.033)) aa.cwt <- wavCWT(aats) x11 (width=10,height=12) plot (aats,main=paste(insig," Cycle: ",j,sep="")) aa.maxtree <- wavCWTTree (aa.cwt,
2005 Jun 15
1
Finding local minima and maxima
I have data in the form of (x,y) pairs and would like to find local minima and maxima (typically the zeros of the 2nd derivative) of the y values. I looked at numericDeriv, but I don't have an "expression" per se. I looked at optim, also, but it looks like it will find only one "global" max or min. I can code up my own piecewise derivatives, but wondered if there is
2017 Aug 26
0
Find maxima of a function
> On 26 Aug 2017, at 16:39, niharika singhal <niharikasinghal1990 at gmail.com> wrote: > > Hi, > > Thanks for your mail, and time > > It is not working for some arguments, when mean value is like >6. > > > case > > mc0 <- c(0.08844446,0.1744455,0.1379778,0.1209769,0.1573065,0. > 1134463,0.2074027) > > rv
2009 Sep 17
1
Turning points in a series
Good morning once more. My problem of yesterday has been addressed. Having learned a few tricks from that, I wish to ask another question in connection with that. My data is a cosmic ray data consisting of dates and counts. When I plot a graph of counts versus dates, the resultant signal shows a number of maximum and minimum points. These minimum points (turning points) are of interest to me.
2006 Dec 11
1
hermite and Bezier splines
Does anyone know how to do hermite or Bezier splines in R? I can find Matlab routines, but really need to implement them in R. Failing that I'd be interested in other conformal splines. I need to smooth and interpolate animal tracking data. Antarctic Wildlife Research Unit School of Zoology University of Tasmania PO Box 252-05 Hobart TAS, 7001 Australia Phone: (0)3 6226 2645 Fax:
2013 Feb 27
1
Finding the knots in a smoothing spline using nknots
Hi r-helpers. Please forgive my ignorance, but I would like to plot a smoothing spline (smooth.spline) from package "stats", and show the knots in the plot, and I can't seem to figure out where smooth.spline has located the knots (when I use nknots). Unfortunately, I don't know a lot about splines, but I know that they provide me an easy way to estimate the location of local
2003 Jan 31
2
minor error in documentation of pmax in base (PR#2513)
The documentation says, "pmax and pmin take several vectors as arguments and return a single vector giving the parallel maxima (or minima) of the vectors." I discovered that, if you use a matrix or array instead of a vector, pmax returns a matrix or array, respectively. This makes pmax and pmin much more useful, and should not be left to people to discover on their own! For example:
2012 Jul 03
2
NADA Data Frame Format: Wide or Long?
I have water chemistry data with censored values (i.e., those less than reporting levels) in a data frame with a narrow (i.e., database table) format. The structure is: $ site : Factor w/ 64 levels "D-1","D-2","D-3",..: 1 1 1 1 1 1 1 1 ... $ sampdate: Date, format: "2007-12-12" "2007-12-12" ... $ preeq0 : logi TRUE TRUE TRUE TRUE TRUE
2010 Mar 29
1
Suggestion: Adding quick rowMin and rowMax functions to base package
Hi, I wonder whether similarly to the very quick rowSums and colSums functions in the base package, one could add quick functions that calculate the min or max over rows / cols in a matrix. While apply(x,1,min) works, I found out by profiling a program of mine that it is rather slow for matrices with a very large number of rows. A quick functionality seems to be already there in the
2010 Oct 20
1
problem with predict(mboost,...)
Hi, I use a mboost model to predict my dependent variable on new data. I get the following warning message: In bs(mf[[i]], knots = args$knots[[i]]$knots, degree = args$degree, : some 'x' values beyond boundary knots may cause ill-conditioned bases The new predicted values are partly negative although the variable in the training data ranges from 3 to 8 on a numeric scale. In order to
2011 Jul 27
2
fitting sine wave
Dear R-helpers ? I have 7 data points that I want to fit a continuous curve to, that should look similar to a sine wave My data points would mark the local minima and maxima respectively. This is what I?ve got so far. And I would keep doing so, but sadly nls() then says that it has reached the maximum number of Iterations? ?
2008 Oct 10
1
how to evaluate a cubic Bezier curve (B-spline?) given the four control points
I'm trying to use R to determine the quality of a cubic Bezier curve approximation of an elliptical arc. I know the four control points and I want to compute (x,y) coordinates of many points on the curve. I can't find anything in either the base distribution or CRAN that does this; all the spline-related packages seem to be about *fitting* piecewise Bezier curves to a data set.
2017 Aug 27
2
Fwd: Find maxima of a function
---------- Forwarded message ---------- From: niharika singhal <niharikasinghal1990 at gmail.com> Date: Sun, Aug 27, 2017 at 11:57 AM Subject: Re: Find maxima of a function To: "David Winsemius [via R]" <ml+s789695n4745009h56 at n4.nabble.com>, "Ismail SEZEN [via R]" <ml+s789695n4744993h60 at n4.nabble.com>, Ulrik Stervbo <ulrik.stervbo at gmail.com>
2011 May 25
0
approximate function and find local peaks (Maxima or Minima)
Hi, I have a data-matrix: > CB                    Zeit                Low 2   2011-05-02 08:05:05 7596.0 3   2011-05-02 08:10:06 7593.5 4   2011-05-02 08:15:11 7594.5 5   2011-05-02 08:20:15 7597.5 6   2011-05-02 08:25:18 7595.0 7   2011-05-02 08:30:20 7593.5 8   2011-05-02 08:35:21 7593.0 9   2011-05-02 08:40:21 7593.0 10  2011-05-02 08:45:25 7599.0 11  2011-05-02 08:50:34 7596.0 12 
2008 May 07
0
Fwd: Re: Solution of function
Forgot to send one copy to R help. Sorry Megh Dal <megh700004@yahoo.com> wrote: Date: Wed, 7 May 2008 02:45:09 -0700 (PDT) From: Megh Dal <megh700004@yahoo.com> Subject: Re: [R] Solution of function To: Berwin A Turlach <berwin@maths.uwa.edu.au> Hi Berwin, Thanks for having look on my problem. However on ipop() function I see following: ipop solves the quadratic
2010 Mar 17
1
Is there any R package that can find the maxima of a 1-D time series
Is there any R package that can help me with digging out the maxima of a 1-D trajectory ? I have 975 1-D curves. They are only known as time series. That is a set of points ordered with respect to time. Some curves exhibit one only peak. Others have two peaks of different height. We wish to find the number of peaks and their position along the time axis. Apparently it's a trivial problem
2009 Nov 03
2
1 dimensional optimization with local minima
I am using numerical optimization to fit a 1 parameter model, in which the input parameter is bounded. I am currently using optimize(), however, the problem turns out to have local minima, and optimize does not always seem to find the global minimum. I could to write a wrapping function that tries multiple intervals or starting values, but I would prefer a package that has built-in methods to make
2008 Feb 21
1
Finding local maxima (height) in a matrix data (6 spatial coordinates)?
Dear all, I wonder which R algorithm could perform a search of local maxima in an spatial grid, in other words, having the coordinates of a map (x,y,z... up to 6 coordinates) and then the altitude/height at each point (h) (in total 7 numerical variables) I would like to localise the peaks (local maxima) of that topological surface. Which R algorithm can perform this? Thanks a lot, Josep Maria,
2007 Apr 26
1
[PATCH]Make wobbly's bezier patch to work with grids that aren't 4x4.
Hi, Recently, I started taking a look at wobbly's source (I was interested in it's physics... ;-)) I noticed that GRID_WIDTH and GRID_HEIGHT were defined to be 4, and I wanted to see how the physics look like with grid sizes that aren't 4x4. I changed the defines to my new grid size, but unfortunately it didn't work. I investigated this "bug" (it's not exactly a bug