similar to: Substituting inside expression

I have found following problem: I have a vector: > a <- c(1.04,1.04,1.05,1.04,1.04) I want a mean of this vector: > mean(a) [1] 1.042 which is correct, but: > mean(1.04,1.04,1.05,1.04,1.04) [1] 1.04 gives an incorrect value. how is this possible? thanks, zbynek -- View this message in context: http://r.789695.n4.nabble.com/Incorrectness-of-mean-tp3327701p3327701.html Sent from the R

I am having problem using output of lm() function for further analysing using systemfit package. Basicaly, the problem s following - I generate several formulas using lm() > fo1 <- lm(r98[,2] ~ f98[,1] + f98[,2] + ... + f98[,43]) > fo2 <- lm(r98[,1] ~ f98[,1] + f98[,2] + ... + f98[,43]) and than I want to estimate a general model using package systemfit. > fitsur <-

I've got the graphic with this: a=c(120,40,75,85,55,75,55,90,90,55,155) plot(ecdf(a)) How can I draw lines to show the lower quatile and upper quartil? I only know there is the argument lines(), but I don't know how to use it -- View this message in context: http://r.789695.n4.nabble.com/How-can-I-draw-a-line-in-empirical-distribution-function-tp3090675p3090675.html Sent from the R

Hi, I have a dataset and I want to fit a function to it. The function is variogram model (http://en.wikipedia.org/wiki/Variogram) The variogram model is defined by three parameters and I want them to be automatically optimized for real time data. I tried to use gafit {gafit} for this, but there are some data configuration, where optimal results given by gafit() are negative, which is not correct

Hello, I am trying to construct two matrices, F and V, composed of partial derivatives and then find the eigenvalues of F*Inverse(V). I have the following equations in ryacas notation: > library(Ryacas) > FIh <- Expr("betah*Sh*Iv") > FIv <- Expr("betav*Sv*Ih") > VIh <- Expr("(muh + gamma)*Ih") > VIv <- Expr("muv*Iv") I

Let's say I had a matrix like this: library(Ryacas) x<-Sym("x") m<-matrix(c(cos (x), sin(x), -sin(x), cos(x)), ncol=2) How can I use R to obtain the eigenvalues and eigenvectors? Thanks, John [[alternative HTML version deleted]]

Dear R-gurus, I know that it is not a R problem, but as need to implement some solution for this on R, I would like to know if someone help me on how to isolate X on the expression below. K=(sen A * sen B ) + ( cos A * cos B * cos ( X - Y ) ) Any help are welcome mitinho astronauta brazil [[alternative HTML version deleted]]

I am having issues with Ryacas errors. I searched and found this error was reported in 2006, but nothing since. > library(Ryacas) Loading required package: XML > yacas(expression(Factor(x^2-1))) [1] "Starting Yacas!" CommandLine(1) : Expecting ) closing bracket for sub-expression, but got ^ instead > yacas("D(x)Sin(x)") CommandLine(1) : Expecting ) closing bracket

Hi I am currently (for pedagogical purposes) writing a simple numerical analysis library in R. I have come unstuck when writing a simple Newton-Raphson implementation, that looks like this: f <- function(x) { 2*cos(x)^2 + 3*sin(x) + 0.5 } root <- newton(f, tol=0.0001, N=20, a=1) My issue is calculating the symbolic derivative of f() inside the newton() function. I cant seem to get R to

Dear all, I am using the function 'D' in the 'stats' package to perform symbolic derivation. This works very well and it is much faster than e.g. Mathematica (at least for my purposes). First, I would like to thank the development team for this excellent function. However, I run into trouble in some cases, particularly when I am to do some operations on long expressions

Ryacas is an R interface to the free yacas computer algebra system. Ryacas allows one to send R expressions, unprocessed yacas strings and certain other R objects to a separate yacas process from R and get back the result. It also has facilities for manipulating yacas strings and R expressions destined for yacas processing. It can be used for exact arithmetic, symbolic math, ASCII pretty

Ryacas is an R interface to the free yacas computer algebra system. Ryacas allows one to send R expressions, unprocessed yacas strings and certain other R objects to a separate yacas process from R and get back the result. It also has facilities for manipulating yacas strings and R expressions destined for yacas processing. It can be used for exact arithmetic, symbolic math, ASCII pretty

Ryacas is an R interface to the free yacas computer algebra system. Ryacas allows one to send R expressions, unprocessed yacas strings and certain other R objects to a separate yacas process from R and get back the result. It also has facilities for manipulating yacas strings and R expressions destined for yacas processing. It can be used for exact arithmetic, symbolic math, ASCII pretty

Dear All I am doing the following: > x <- yacas("3/2") > for (i in 2:400) + x <- yacas(paste(x,"*",x)) > x expression(Inf^1.260864167e+117/Inf^6.304320836e+116) > Eval(x) [1] NaN No luck this way. However, I am successful with > y <- yacas("(3/2)^400") > y expression(7.05507910865533e+190/2.58224987808691e+120) > Eval(y) [1]

Hi all, I am trying to implement the following matlab code with Ryacas : syms U x x0 C d1=diff(U/(1+exp(-(x-x0)/C)),x); pretty(d1) d2=diff(U/(1+exp(-(x-x0)/C)),x,2); pretty(d2) solx2 = solve(d2 == 0, x, 'Real', true) pretty(solx2) slope2=subs(d1,solx2) I have tried the following : library(Ryacas) x <- Sym("x");U <- Sym("U");x0 <-

Hi I have a data frame with 40,000 rows and 4 columns, one of which is "class". For each row, the "class" column can be one of 10 possible NUMERIC values. I wish to substitute these numeric values with words/characters. For example, I wish to substitute all occurences of "5467" in the column "class" with "alpha", "7867" with

Thanks for the response. Yes, I did study the vignette but did not understand it fully. Anyway, I have tried once again now. I am happy to say that I have got what I wanted. library(Ryacas) x <- Sym("x");U <- Sym("U");x0 <- Sym("x0");C <- Sym("C") my_func <- function(x,U,x0,C) { return (U/(1+exp(-(x-x0)/C)))} FirstDeriv <-

Have you studied the "Introduction to Ryacas" vignette that come with the package? Cheers, Bert Bert Gunter "The trouble with having an open mind is that people keep coming along and sticking things into it." -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip ) On Tue, Sep 19, 2017 at 2:37 AM, Vivek Sutradhara <viveksutra at gmail.com> wrote:

Hello yet again, R People: I was working with Ryacas and yacas last night and all was well. Now this morning, I keep getting the following: > a <- Sym("a") > a Error in summary.connection(x) : invalid connection > When I go to yacas from the command line, it works fine. Any suggestions, please? I'm thinking that a port might be open, but here I have: >

Hello again. Now I have the following: > xx [1] "Solve(1 - R/100==(2*y)/10000,R)" > yacas(xx) expression(list(R == 100 * (1 - 2 * y/10000))) > I would like to put in a value for y and obtain R. I've tried more stuff with eval and Eval, but no luck yet. Any suggestions would be much appreciated. Thanks, Erin -- Erin Hodgess Associate Professor Department of Computer