similar to: Integrate two function in R

Hi, I'm a student studing for Math. & Infor. Ing. in Tirana,Albania and a have a final project in R to finish in a week, so I badly need your help... The topic of the project is "Hermite Interpolation" and a I have allready done a script that finds the approximation in a certan point x, H(x) ~f(x) but i want to find the value of his derivative H'(x)~f'(x) as well and to

Dear All, I am trying to solve the following maximization problem with R: find x(t) (continuous) that maximizes the integral of x(t) with t from 0 to 1, subject to the constraints dx/dt = u, |u| <= 1, x(0) = x(1) = 0. The analytical solution can be obtained easily, but I am trying to understand whether R is able to solve numerically problems like this one. I have tried to find an

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

Hola a todos Me gustaría calcular la integral indefinida (primitiva) de una función respecto un parámetro. Al estilo de lo que hace la función D, pero al reves > s <- expression(5*x^2+2 ) > D(s,"x") 5 * (2 * x) Con integrate hay que indicar a la fuerza los límites de la integral, y con Ryacas no funciona nada, ya que no se conecta a su ip ¿Conocéis alguna forma? Saludos

Dear all, I have some issues with integrate in R thus I would like to request your help. I am trying to calculate the integral of f(x)*g(x). The f(x) is a step function while g(x) is a polynomial. If f(x) (step function) changes its value only few times (5 or 6 'steps') everything is calulated ok(verified results in scrap paper) but if f(x) takes like 800 different values I receive the

Hello, I am a student and I working with R. I want to ask you how to solve this integral which is shown in image attach with this letter. And how to draw this function z = 4 ? x2 ? y2 , width intervals x = ?1, y = ?1. Thank You. Yours sincerely, Jolanta

I want to integrate the function (sin^7*x)*(cos^8*x)dx. I do not have values to integrate between. I just want R to give me the integral of the function. For example R takes the derivative of the function by d1=D(expression(x^2*(cosh*(x^3))), "x"). Is there a similar function available in R to find the integral? Thanks, Kim

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

Hello I would like to calculate a weighted line integral. The integral is calculated by the cells that this lines trasverses (the small cells belong to matrix (m*n) that represent the value that a specific area has. I need to calculate the weights by finding out how much the line touches or impinges inside a cell. The weight is less if a line just touches one of the four edges of a square

Hi all, I have a polynomial (a big one) and I would like to find a root of it between [-inf, -3] (it's known there is one root in this interval)... How to find that root? In using "uniroot" I need to supply the bounds.... In using "polyroot" I need to write it in the strict sens polynomial format... but I cannot... i.e. the polynomial is implicit... Thank you!

Un saludo cordial para cada uno. Les agradecería una ayuda con lo siguiente: Debo trabajar con una función de varias variabes, digamos f(x,y,z). ¿Cómo definir la función para usarla luego con ''integrate'' de forma tal que pueda fijar dos valores, ''y'' y ''z'', por ejemplo, e indicar los límites de integración para la variable que queda libre?

Hello everyone, I would like to find out if there are already implemented function for legendre polynomials. I tried google but returns nothing. How do you suggest me to search for that? Regards Alex [[alternative HTML version deleted]]

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

Hello, I am trying to find the analytical solution to this differential equation dR/dt = k1*(R^k2)*(1-(R/Rmax)); R(0) = Ro k1 and k2 are parameters that need to fitted, while Ro and Rmax are the baseline and max value (which can be fitted or fixed). The response (R) increases initially at an exponential rate governed by the rate constants k1 and k2. Response has a S-shaped curve as a function

Hey, I'm trying to find how to perform operations with a variable treated as a symbol. For, an extremely simple, example I want to integrate a*x with respect to x and I want to find the indefinite integral of this, (a*x^2/2), or the definite integral with some interval for x. Another example of such a use would be to create a function y<-function(x) {a*x} and by typig y(2) I would get the

Hi all, We know that Hermite polynomial is for Gaussian, Laguerre polynomial for Exponential distribution, Legendre polynomial for uniform distribution, Jacobi polynomial for Beta distribution. Does anyone know which kind of polynomial deals with the log-normal, Student抯 t, Inverse gamma and Fisher抯 F distribution? Thank you in advance! David [[alternative HTML version deleted]]

Hi all, is there any package in R capable of smooth approximation of CDF basing on given sample? (Thus, I am not speaking about ecdf) In particular, I expect very much that the approximation should subject to the property: f(x0)<=f(x1) for x0<x1, where x0 and x1 belong to range of the sample given. Polynomial approximation could be OK for me as well. P.S.

Hi R users, I have a couple of questions about some problems that I am facing with regard to numerical integration and optimization of likelihood functions. Let me provide a little background information: I am trying to do maximum likelihood estimation of an econometric model that I have developed recently. I estimate the parameters of the model using the monthly US unemployment rate series

Hi guys again, it seems I haven't been doing the maximum likelihood estimation correctly. I quote below, can someone explain to me please what does it mean that the 2nd and 3rd derivatives of the function equals zero and how to compute that in R. "We have our initial estimated, subjective parameters for the gamma mixture and we have our likelihood that is the mixture of negative

Hi, I noticed a minor flaw in integrate() from package stats: Taking up arguments lower and upper from integrate(), if (lower == Inf) && (upper == Inf) or if (lower == -Inf) && (upper == -Inf) integrate() calculates the value for (lower==-Inf) && (upper==Inf). Rather, it should return 0. Quick fix: ### old code ### ### [snip] else {