search for: polynoms

Hello, I have 3 columns : a, b and a*b I would like to find the pair (a,b) so that a*b is the minimum but not from the points I measured but from the fit of the curve (I have more points that the ones given below but I fit only on this part because I know that the minimum a*b is in this interval). I thought doing it this way : - to fit a*b=f(a) abfit<-lm(ab ~ poly(a,8,raw=T)) - to use the

Merci beaucoup, Jean, for the bug report -- which I'm no "completeing" to R-bugs >>>>> "Jean" == Jean Coursol <coursol@cristal.math.u-psud.fr> >>>>> on Thu, 24 Jun 2004 15:22:37 +0200 (CEST) writes: Jean> I was exploring the polynom library with students: <and found a segmentation fault from parsing a long expression>

Dear R people: I am trying to download the package polynom to R version 1.0.1.1. on Windows. Here are my commands and output: > install.packages("polynom",lib="c:\rw1011\library",CRAN="http://www.r-project.org/src/contrib/") Error in start[k]:(start[k + 1] - 1) : NA/NaN argument In addition: Warning message: Download had nonzero exit status in:

hi there, can anyone help me on the topic of frag polynoms? i just heard of a friend of mine, that i could build in a functioon called fragpoly (he was talking of such a function in the 'stata' language) in order to improve my process of finding an optimal linear model. instead of trying a vast amount of transformed inputdata to find the best fit...

Hi, I can not comprehend the linear fitting results of polynoms. For example, given the following data (representing y = x^2): > x <- 1:3 > y <- c(1, 4, 9) performing a linear fit > f <- lm(y ~ poly(x, 2)) gives weird coefficients: > coefficients(f) (Intercept) poly(x, 2)1 poly(x, 2)2 4.6666667 5.6568542 0.8164966 However the...

Something strange is happening with update.packages on my machine (Win2000, R-1.5.0 installed from binaries). Some of the packages (see below) keep getting updated every time. When I issue update.packages() I get this every time for the last few days (I think since I installed 1.5 and the packages but I am not sure). This happens with CRAN shown below and also with CRAN set to

Dear R-users, is there any package that allows for a division of two polynomials? Regards, M. Fischer Dr. Matthias Fischer Friedrich-Alexander-Universit?t Erlangen-N?rnberg Lehrstuhl f?r Statistik und ?konometrie Lange Gasse 20 90403 N?rnberg Telefon: 0911 / 5302-271 Telefax: 0911 / 5302-277 E-Mail: Matthias.Fischer at wiso.uni-erlangen.de

I've packaged Bill's polynom add-on for R (i.e., converted man pages and took care of TITLE and INDEX). Apart from the missing poly() everything should be fine ... The package can be found in the CRAN src/contrib area. I've also added it to the Debian ix86 r-contrib package. -k =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- r-devel mailing list --

Good day everyone, I want to use the Gram-Charlier series expansion to model some data. To do that, I need functions to: 1) Calculate 'n' moments from given data 2) Transform 'n' moments to 'n' central moments, or 3) Transform 'n' moments to 'n' cumulants 4) Calculate a number of Hermite polynomials Are there R-functions to do any of the above?

Any better (more efficient, built-in) ideas for computing coef[1]+coef[2]*x+coef[3]*x^2+ ... than polynom <- function(coef,x) { n <- length(coef) sum(coef*apply(matrix(c(rep(x,n),seq(0,n-1)),ncol=2),1,function(z)z[1]^z[2])) } ? Ben -- 318 Carr Hall bolker at zoo.ufl.edu Zoology Department, University of Florida http://www.zoo.ufl.edu/bolker

Please, I'm a beginner with the R language. I'm looking for a function to compute a Polynomfit for simple x-y Data. Who can help? Many Greetings E.A. Welge -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the

I'm one of the many who is far more interested in the reason for the request than in the numerical method to use. The way I see it, the methodology of, say, polyroot() suffices in a mathematical sense. If your coefficients are mathematically exact (as opposed to measured values), the near-singularities and such don't really matter, assuming infinite precision math. So, what

From: jypuppy36@hotmail.com To: r-help-bounces@r-project.org Subject: R programing help-newton iterations for the square root Date: Tue, 7 Dec 2010 12:00:01 -0800 NEWTON ITERATIONS FOR THE SQUARE ROOT Newton iterations to find the root of a real valued function f , i.e. a number x for which f (x) = 0, are of the form Example. To find the square root of a positive number y we can use

Hello, I'm trying to fit some points with a 8-degrees polynom (result of lm is stored in pfit). In most of the case, it is ok but for some others, some coefficients are "NA". I don't really understand the meaning of these "NA". And the problem is that I can't perform a derivation (pderiv<-as.function((deriv(polynomial(pfit$coefficients))))) on pfit due to the

Dear all, I'm looking for how can I estimate a linear model with ar(ma) errors : y(t)=a*X(t)+e(t) with P(B)e(t)=Q(B)u(t) where u is a white noise and P, Q are some polynomes. Could you help me ? Gr?gory Benmenzer

Hi, I would like to get the coefficient of polynomial expansion. For example, (1+ x)^2 = 1 + 2x + x^2, and the coefficients are 1, 2 and 1. (1 + x + x^2)^3 = 1 + 3*x + 6*x^2 + 7*x^3 + 6*x^4 + 3*x^5 + x^6, and the coefficients are 1, 3, 6, 7, 6, 3, and 1. I know that we can use polynom library. Is there any other way to do it without loading a library. Thanks a lot for your help. Peter

Full_Name: Jens Keienburg Version: 2.3.0 OS: Windows XP Submission from: (NULL) (193.174.53.122) I used the function lm() to calculate the coefficients of a polynome. If I used the function poly(t,2) to denote a polynome of form 1 + x + x^2, the coefficients are wrong. I appended an excerpt below: > t=1:100 > p=-20 - 10 * t + 2 * t^2 > p [1] -28 -32 -32 -28 -20 -8 8

...ARIMA model in the case where I have some specific knowledge about the coefficients that should be included in the model. Take a classical ARIMA (or even ARMA) model: P(B) X(t) = Q(B) epsilon(t), where X(t) is the data, epsilon is a white noise, B is the backward operator and P and Q are some polynoms. Additionally, assume that you know in advance how P and Q look like. Typically, P could be something like this: P(x) = (1 - a(1)*x - a(2)*x^2) * (1 - b(1)*x^23 - b(2)*x^24) * (1 - c(1)*x^168) (That is in the case of hourly data, with lags 23 and 24 corresponding to the day, and lag 168 for th...

Awaiting some suggestion. Was my question not very understandable? Please let me know how can I offer more elaborate clarification. Additionally, I would like to solve the determinant of "p1" for the values of "z" (I am working with some multivariate time series modelling). When I use det() function, it am getting error that, that function is not for objects with class

Hi, I would like to get the coefficients of x^0, x^1, x^2, . , x^6 from expansion of (1+x+x^2)^3. The result should be 1, 3, 6, 7, 6, 3, 1; How can I calculate in R? You help will be greatly appreciated. Peter [[alternative HTML version deleted]]