similar to: adding an ellipse to a PCA plot

Dear R users, When I use aggregate with table as FUN, I get what I would call a strange behaviour if it involves numerical vectors and one "level" of it is not present for every "levels" of the "by" variable: --------------------------- > df <- data.frame(A=c(1,1,1,1,0,0,0,0),B=c(1,0,1,0,0,0,1,0),C=c(1,0,1,0,0,1,1,1)) >

Dear fellow users Are there any Vietnamese language resources for beginners of R? If so, I would be interested in hearing from people who have had experience with them and which are better (if there is more than one). I am involved with an aid project in Vietnam, and would like to move the scientists involved from using Excel for 'analysis' to R. Thanks .... Peter Alspach The

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

Hi Alejo, According to my knowledge the two plots are different because in the first one a point belongs to a group depending on its group in the data whereas in the second plot a point belongs to the group predicted by the linear discriminant analysis. I hope somebody will correct me if I am wrong. Alain Alejo C.S. wrote: > Hi Alain, this is the code: > > > library(MASS) >

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

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

Last week I asked about data ellipses with rgl:::ellipse3d() with lines showing the principal axes. (The goal is a visual demonstration of PCA as a rotation of variable space to component space.) I was trying, unsuccessfully, to use princomp() to generate the PCA axes and plot them using segments3d: > > PC <- princomp(trees) > > sdev <- PC$sdev # component standard

Hi, my data frame consist of 8 Variables and 120 000 observations. With those datas I am running a PCA and after I want to calculate the Volume of the PCA-cloud of certain subsets of my data. Does anyone have an idea about a function that can do this? Thanks [[alternative HTML version deleted]]

Hi!, I made a plot with two variables representing the first two axis of a principle component analysis. My question is: How can I superimpose on such plot an ellipse that represent the 95% interval of confidence of scores? Best regards, Paula -- Lic. Paula Gonzalez Divisi??n Antropolog??a Museo de La Plata. Facultad de Ciencias Naturales y Museo. UNLP. Paseo del Bosque s/n?? - B1900FWA - La

Don't use aggregate's simplify=TRUE when FUN() produces return values of various dimensions. In your case, the shape of table(subset)'s return value depends on the number of levels in the factor 'subset'. If you make B a factor before splitting it by C, each split will have the same number of levels (2). If you split it and then let table convert each split to a factor, one

Is there an option to draw concentration ellipses in biplots ? It seems really nice to summarize large number of points of each group. Cheers../ Murli

Dear R helpers I have one data as given below. date                     value1          value2             value3 30-Nov-2010           100                 40                 61 25-Nov-2010           108                 31                 88 14-Sep-2010            11                 180               56 I want the following output date                 name       amount 30-Nov-2010      value1

Hi, I was trying as well as looking for an answer without success (a bit strange since it should be an easy problem) and therefore I will appreciate you help: My simple script is: # Loadings data of 5 columns and 100 rows of data data1<-read.csv("C:/?/MyPCA.csv") pairs(data1[,1:4]) pca1 <- princomp(data1[,1:4], score=TRUE, cor=TRUE) biplot(pca1) The biplot present the data

Hi I'm trying to make a 3d plot showing a point cloud, the corresponding data ellipse and the principal axes of the ellipse as vectors. library(rgl) data(trees) cov <- cov(trees) mu <- mean(trees) plot3d(trees, type="s", size=0.5, col="blue", cex=2) In this step, an extra box is added. I've tried using box=FALSE, but it has no effect. # how to avoid the

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 =

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

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 ?

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 <-

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

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) ?