search for: ellipses

Hi, I'm using the R library(car) to draw confidence/prediction ellipses in a scatterplot. >From what i understood the ellipse() function return an ellipse based parameters: shape, center, radius . If i read dataEllipse() function i can see how these parameters are calculated for a confidence ellipse. ibrary(car) a=c(12,12,4,5,63,63,23) b=c(13,15,7,10,73,83,43)...

Hello everyone I really need some help here. I made a confidence ellipse using the function ellipse from the package ellipse: ellipse(SD, centre=colMeans(pcsref),t=sqrt((p * (n-1)/(n-p))*qf(0.99, p,n-p)) Now, I want to write a function whom return TRUE or FALSE if a given observation is in the confidence ellipse. But I have no clue how to do it Can anyone help me? Best regards Jessica

Hi: Does Ellipse and dataellipse function in R produce the same ellipse? I wanted to see how the radius for the Ellipse function in R calculated. Also what is the var-covariance matrix, if any, assumed for the dataellipse function? Heres an example of the code where I am generating Multivariate normal data and creating ellipse using the 2 functions: library(car) library(mvtnorm) mu =

Full_Name: Volker Franz Version: Version 1.6.2 (2003-01-10) OS: Debian Submission from: (NULL) (192.124.28.104) Hi there, it seems to me that data.ellipse of package "car" (Version 1.0-1) produces confidence interval's which are too big. To see this, do: library(car) plot(c(-2,2),c(-2,2),pch=0) data.ellipse(rnorm(10000),rnorm(10000),levels=0.68,plot.points=F) abline(v=+1)

library (ellipse) shape1 = c (1, 0, 0,1) dim(shape1) = c(2,2) ellipse (center = c(0,0), shape = shape1, radius = 1) ============================= Error in plot.xy(xy.coords(x, y), type = type, col = col, lty = lty, ...) : plot.new has not been called yet It is really frustrating. Also what do the shape matrix, radius correspond to an ellipse function (x-x0)^2/a + (y-y0)^2/b = 1 ?

Hello, SAS' point and click interface has the option of produce a scatterplot with a superimposed confidence ellipse for the correlation coefficient. Since I generally like R so much better, I would like to reproduce this in R. I've been playing with the ellipse package. In order to have the points and the ellipse on the same graph I've done the following. (Load ellipse

Hi, I drew an ellipse with the package ellipse. Now I would like to know if a point is inside the ellipse. Is any R functions to do it without computing the equation of the ellipse manually? Thanks. For example, if I do "plot(ellipse(0.8), type = 'l')", I would like to know if (0,1) belongs to the drawn ellipse. Regards, Alain -- Alain Guillet Statistician and Computer

I have empirical Bayes estimates for slopes and intercepts for a number of subjects and I would like to plot the slopes and intercepts with confidence ellipses. These ellipses would be based on the confidence intervals for the slope and intercepts (forming the major and minor axis of each ellipse), and the correlation in the slope and intercepts. The ellipse function in the car library looks like the way to go, the add= argument would allow me to o...

Dear list members, This might be a silly question but I just can't figure it out. I am using the "ellipse" package on covariance matrices. I would simply like to plot my ellipses WITH its two axis ploted as well. These axis represents the 2 eigen vectors of my matrix and it is important that I can graphically show them. Is there an easy way to do so? Many thanks, Antoine -- View this message in context: http://r.789695.n4.nabble.com/Adding-axis-to-an-ellipse-ellipse-packa...

Hello, has anybody written a function to plot density ellipses (95%, 99% or anything) in a scatterplot? I found nothing in any package, nor in the list archives. There does seem to be a contributed package "ellipse" for S-Plus (on S-Archive), but it does a lot more than what I would need. Still, if anybody ported it to R, I'd be grateful for a...

Dear All, I would be very appreciative of your help with the following 1). I am running multivariate multiple regression through the manova() function (kindly suggested by Professor Venables) and getting two different answers for test=c("Wilks","Roy","Pillai") and tests=c("Wilks","Roy",'"Pillai") as shown below. In the

Hi, I'm running into an issue while using FreeBSD 5.4, NUT from ports (2.0.3), serial on /dev/cuaa1, Ellipse 1200 USBS. The ups.conf is : [ellipse] driver=mge-utalk port=/dev/cuaa1 desc="Telecom Closet Ellipse" When I go to start it I get : Network UPS Tools - UPS driver controller 2.0.3 Network UPS Tools - MGE UPS SYSTEMS/U-Talk driver 0.87 (2.0.3)

Hi, I created a principal component plot using the first two principal components. I used the function princomp() to calculate the scores. now, I would like to superimpose an ellipse representing the center and the 95% confidence interval of a series of points in my plot (as to illustrate the grouping of my samples). I looked at the ellipse() function in the ellipse package but can't get it

Hello, R-Help - I am trying to plot the results of an ordination from package vegan. The tricky part for me right now is getting the colors of the ellipses denoting the 95% confidence intervals of the group centroids to match the colors of the points for those same groups. >From and earlier post, I saw the code to make a plot of the ordination using different colors for my different groups. My functional code is below: library(vegan) comvars &lt...

John Fox wrote: >The confidence ellipse for a pair of coefficients is just (with an >adjustment for size) the perpendicular shadow of the joint ellipsoid, in >the same sense that the confidence intervals for individual coefficients >are shadows of the joint ellipsoid or ellipse. The usual confidence ellipse >for 2 of q coefficients uses qf(.95, 2, df.error) to scale the ellipse; if

Hello again, First I want to thank all the people who answered my question about line width in graphs. I promise I will learn the 'par' help page by heart for the end of the month ! I now want to trace some ellipses to emphasize groups of data. I found how to trace circles with 'symbols()', but no ellipse. I'm planning on writing my own function based on 'polygon()' and the ellipse equation. Does anybody already have done similar work or have another solution ? Thanks again, -- Ir. Y...

Dear S-PLUS/R users: Do you know any default function or a user contributed function that can draw an ellipse with given axes and origin? Thanks for any help. Paul. -- Romance, like alcohol, should be enjoyed, but should not be allowed to become necessary. -- Edgar Friedenberg -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list --

I can take the results of a simulation with one random variable and generate an empirical interval that contains 95% of the observations, e.g., x <- rnorm(10000) quantile(x,probs=c(0.025,0.975)) Is there an R function that can take the results from two random variables and generate an empirical ellipse that contains 95% of the observations, e.g., x <- rnorm(10000) y <- rnorm(10000) ?

Hi, FreeBSD 5.4, NUT from ports (2.0.3), serial on /dev/cuaa1, Ellipse 1200 USBS. I set the ups.conf up as : [ellipse] driver=mge-utalk port=/dev/cuaa1 desc="Ellipse" When I go to start it I get : Network UPS Tools - UPS driver controller 2.0.3 Network UPS Tools - MGE UPS SYSTEMS/U-Talk driver 0.87 (2.0.3) Could not get multiplier table: using raw

I have been using the ellipse function from the car package and the covariance matrix to draw an ellipse around a group of points to show the confidence limits. However, the points are actually represented by 3 variables so rather than plot each pairwise combination of variables in 2D I would like to plot the 'ellipse' in 3D using the djmrgl package. Can anyone offer advice on how I can