Displaying 20 results from an estimated 6000 matches similar to: "wishlist: xlim in lines.polynomial (PR#9362)"
2010 Oct 14
1
Fw: Problem to create a matrix polynomial
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
2005 Aug 08
2
coefficient of polynomial expansion
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
2010 Oct 05
2
Using as.polynomial() over a matrix
Hello All
First - a warning. I'm not very R or programming savvy.
I am trying to do something without much luck, and have scoured help-pages, but nothing has come up. Here it is:
I have a matrix (m) of approx 40,000 rows and 3 columns, filled with numbers.
I would like to convert the contents of this matrix into another matrix (m_p), where the numbers of (m) have been coerced into a
2002 Oct 09
5
polynomial
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
2013 Mar 01
2
solving x in a polynomial function
Hi there,
Does anyone know how I solve for x from a given y in a polynomial
function? Here's some example code:
##example file
a<-1:10
b<-c(1,2,2.5,3,3.5,4,6,7,7.5,8)
po.lm<-lm(a~b+I(b^2)+I(b^3)+I(b^4)); summary(po.lm)
(please ignore that the model is severely overfit- that's not the point).
Let's say I want to solve for the value b where a = 5.5.
Any thoughts? I did
2006 Oct 09
1
Coefficients of a factorized polynomial
Hi all,
starting from a vector "v[1:n]" I would like to compute the coefficients
of the polynomial (1+x^v[1])*(1+x^v[2])*...*(1+x^v[n]). The following
code works but is extremely slow for a large "n" due to, I believe, the
polynomial being factorized. I wanted to try the package "polynom"
command "unclass" but I could not figure out how to input a
2007 Nov 06
1
How to find the zero (only the real solution) with the package polynom ?
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
2009 May 14
1
automated polynomial regression
Dear all -
We perform some measurements with a machine that needs to be
recalibrated. The best calibration we get with polynomial regression.
The data might look like follows:
> true_y <- c(1:50)*.8
> # the real values
> m_y <- c((1:21)*1.1, 21.1, 22.2, 23.3 ,c(25:50)*.9)/0.3-5.2
> # the measured data
> x <- c(1:50)
> # and the x-axes
>
> # Now I do the following:
2004 Dec 03
3
Computing the minimal polynomial or, at least, its degree
Hi,
I would like to know whether there exist algorithms to compute the
coefficients or, at least, the degree of the minimal polynomial of a square
matrix A (over the field of complex numbers)? I don't know whether this
would require symbolic computation. If not, has any of the algorithms been
implemented in R?
Thanks very much,
Ravi.
P.S. Just for the sake of completeness, a
2004 Jun 25
4
Bug in parse(text = <long polynom>) (PR#7022)
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>
2008 Oct 15
4
a really simple question on polynomial multiplication
Dear R people:
Is there a way to perform simple polynomial multiplication; that is,
something like
(x - 3) * (x + 3) = x^2 - 9, please?
I looked in poly and polyroot and expression. There used to be a
package that had this, maybe?
thanks,
Erin
--
Erin Hodgess
Associate Professor
Department of Computer and Mathematical Sciences
University of Houston - Downtown
mailto: erinm.hodgess at
2001 Jul 09
1
polynomial regression and poly
When doing polynomial regression I believe it is a good idea to use the poly
function to generate orthogonal polynomials. When doing this in Splus there
is a handy function (transform.poly I think) to convert the coefficients
produced by regression with the poly function back to the original scale.
Has somebody written something similar for R ?
Robert
2007 Nov 07
3
Can I replace NA by 0 (if yes, how) ?
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
2003 Apr 23
1
Setting up Xemacs + Sweave
Dear list,
I have tried to setup my Xemacs for use with Sweave, which I indend to learn.
I have followed the instructions in the Sweave FAQ, that is to say, I put
(defun Rnw-mode ()
(require 'ess-noweb)
(noweb-mode)
(if (fboundp 'R-mode)
(setq noweb-default-code-mode 'R-mode)))
(add-to-list 'auto-mode-alist '("\\.Rnw\\'" . Rnw-mode))
(add-to-list
2009 Jun 03
0
fitting polynomial, for integration.
Hello,
I have a question regarding fitting a polynomial to a data set, then
constructing a polynom from the coefficients so that I can integrate it. I
first use lm to fit the polynomial setting the coefficients to raw=TRUE -
this appears to work fine. I plot the model and it is a true
representation of the data.
I then take the coefficients vector and construct a polynom from the
2006 Feb 22
1
Gram-Charlier series
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?
2009 Jan 11
4
How to get solution of following polynomial?
Hi, I want find all roots for the following polynomial :
a <- c(-0.07, 0.17); b <- c(1, -4); cc <- matrix(c(0.24, 0.00, -0.08,
-0.31), 2); d <- matrix(c(0, 0, -0.13, -0.37), 2); e <- matrix(c(0.2, 0,
-0.06, -0.34), 2)
A1 <- diag(2) + a %*% t(b) + cc; A2 <- -cc + d; A3 <- -d + e; A4 <- -e
fn <- function(z)
{
y <- diag(2) - A1*z - A2*z^2 - A3*z^3 - A4*z^4
2004 Aug 09
0
returns the value of a polynomial of degree n evaluated a t x.
Try something like:
install.packages("polynom")
library(polynom)
predict(polynomial(rev(p)), x)
HTH,
Andy
> From: McClatchie, Sam (PIRSA-SARDI)
>
> > Background:
> > OS: Linux Mandrake 9.1
> > release: R 1.9.0
> > editor: Xemacs 21.4
> > frontend: ESS 5.1.23
> > ---------------------------------
> >
> > Colleagues
> >
2004 Aug 09
1
returns the value of a polynomial of degree n evaluated at x.
> Background:
> OS: Linux Mandrake 9.1
> release: R 1.9.0
> editor: Xemacs 21.4
> frontend: ESS 5.1.23
> ---------------------------------
>
> Colleagues
>
Is there a function in R that is similar to polyval in matlab? (y =
polyval(p,x) returns the value of a polynomial of degree n evaluated at x.
The input argument p is a vector of length n+1 whose elements are the
2003 Oct 01
3
fitting Markov chains
I need to find a computationally simple process for the movement of
interest rates. In this simplified model, an interest rate can have
3--5 possible values, and its movement is characterized by a matrix of
transition probabilities (ie, it is a Markov process).
I would like to estimate this process from a given set of data.
For example, let the interest rate time series be:
7 3 8 2 5 9 6