similar to: Observation in a confidence ellipse

Hello everyone. In my last post I did not explained my problem quite well. I made a principal component analysis and took the 2 first principal components. I made ​​a chart of my points based on the score of the 2 PC. I would like to add on this graph a 95% confidence region. To do this I used the ellipse function as follows: pcsref=PC$score[data[,1]==ref,1:2] #matrix containing the scores

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) v <-

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 =

Hi, I have to construct an ellipse interval region on a PCAbiplot, I have my parameters "a" and "b" and I would apply the formula: draw.ellipse(x, y, a = , b = ) I have done a PCA on my data so I have my scores and loading for the first and second component, but my answer is what I have to choose as X and Y into the formula? if "a" and "b" are scalars or

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

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

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

Dear mailing list, I have following array: X2 Y2 [1,] 422.7900 6.0 [2,] 469.8007 10.5 [3,] 483.9428 11.0 [4,] 532.4917 25.5 [5,] 596.1942 33.5 [6,] 630.8496 40.5 [7,] 733.2996 45.0 [8,] 946.4779 32.0 [9,] 996.8068 35.5 [10,] 1074.3310 23.0 I do afterwards the following: plot.new() plot.window(xlim=c(min(X1)-50,max(X1)+50),

I have a 3xN matrix of parameters obtained from N regressions where the 3 parameters are jointly statistically significant. I would like to reproduce a 3D confidence ellipsoid projecting 2D ellipses onto the XY plane as in Figure 5.2 in this

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

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 link. I'm a bit afraid to try the

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 --

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.

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

Hi, I would like to plot a set of paired means (as X Y data) with unique confidence intervals for each (creating a set of ellipses, each with it's own centre point and shape). Would appreciate any advice out there! Cheers, Ged [[alternative HTML version deleted]]

hello, sorry for posting what may be a simple question: i do have a matrix of coordinates (positional judgments, see below) and now want to calculate and plot the corresponding error ellipse. can anyone help me with the exact steps/syntax? > xyDat X Y 1 -0.49 -2.13 2 0.91 0.48 3 0.20 -2.80 4 -0.76 -3.23 5 -0.36 2.50 6 1.38 1.24 7

Hello, I'm developing an ordination using metaMDS (package vegan). The analysis identifies 3 distinct groups that I'd like to define by either adding circles or ellipses to help identify the groups. The data set is a spatial temporal data base depicting change in each of 4 areas over 3 time periods. I can add lines that would link each of the time - x - area trajectories, but

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

Hi, I used to get a really useful graph when I ran the following command using the MASS library: > cov.rob(cbind(dekeyser$AGE,dekeyser$GJTSCORE),cor=T) Besides the regular output, a graph appeared that had the classical correlation and the robust correlation, and two ellipses, one surrounding the data that would be used in the classical correlation and the other surrounding the data in the