similar to: Calculating the overlapping area of ellipsoides

Hello, I'm working with a series (30+) of hydrologic metrics and 10 vegetation communities and I need to determine which of the metrics provide the best separability for each of the vegetation communities. The hydrologic metrics are highly correlated, therefore the need to reduce the number of them considered is critically important. I've been looking at the scatter3d function in the

Hi, I am using the scatter3d function in Rcmdr to plot the first 3 principal components, I have a grouping variable of 2 groups, and tried to plot points with different colors, somehow I couldn't change the default colors of the 2 groups (blue and green)by using option points.col=c('red','blue'), what's the problem here? scatter3d(all.pca$x[,2],all.pca$x[,3],all.pca$x[,1],

hello, I wish to create some 3d scatter diagrams visualising different grouped data set by a given field in the database. I tried the scatterplot3d package, as well as the plot3d and scatter3d functions (both within the rgl resp. Rcmdr package). My first question is, whether is it possibe to group data in the scatterplot3d and plot3d, because I did not succeed to use the groups = ...

Hello All, I am a R newbie and am probably misinterpreting something really obvious... In the Rcmdr package there is a scatter3d() function that can fit a curve and also provide coefficients for the model. If I'm understanding this right, I think it's calling the lower level stats package function lm(), which is the part that actually does the curve fitting. Anyway, what has me

Dear List, I don't get scatter3d to color the sheres according to the '|' argument. library(car) scatter3d(prestige ~ income + education|type, data=Prestige) The spheres on my screen are all colored the same and they are not conditional on Prestige$type. On the other hand: Fit3d and Ellipse3d are colored according to the group argument. rgl_0.92.879 car_2.0-12 R version 2.15.0

Hi folks, I'd like to use scatter3d (which is in R commander) to plot more than one dataset in the same graph, each dataset with a different color. The kind of stuff you would do with "holdon" in Matlab. I read a recent message that was posted to this list with a similar problem, but I couldn't understand the reply. Could someone give me one example? How do you plot subgroups

Hello, in a three dimensional coordinate system, I'd like to find all my experimental data points that fall within an ellipsoid around a fixed coordinate. The fixed point is defined by (x.coord.point, y.coord.point, z.coord.point). The coordinates of the ellipsoid are given by the three vectors x,y,z. In a previous version of my code, I simply used a box instead of an ellipsoid to sort

+ Hello, The parametric equations of an ellipsoid can be written in terms of spherical coordinates. The three spherical coordinates are converted to Cartesian coordinates by X=a cos (α) sin(θ) Y=b sin(α) sin(θ) Z=c cos(θ) for α and θ The parameter α varies from 0 to 2 π and θ varies from 0 to π . Here ( X o , Y o ,Z o ) is the center of the ellipsoid, and θ is the angle

Dear list, I'm trying to visualise some ellipsoidal shapes in 3D. Their position, axes, and angular orientation can be arbitrary. I saw an ellipse3d function in rgl; however it is heavily oriented towards the statistical concept of ellipse of confidence, whilst I am just concerned with the geometrical object. Below is my current implementation. It is quite slow when creating many shapes, so

Hi all, Can anyone please guide me how to draw a Concentration ellipsoid for a bivariate system with a bivariate normal dist. having a VCV matrix : Sigma <- matrix(c(1,2,2,5), 2, 2) I would like to draw in using GGPLOT. Your help will be highly appreciated. Thanks, -- View this message in context: http://www.nabble.com/Concentration-ellipsoid-tp25315705p25315705.html Sent from the R help

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

Dear list, I've generated a list of 3D coordinates representing ellipsoids in arbitrary orientations. I'm now trying to obtain a 2D projection of the scene, that is to draw the silhouette of each object on a plane (x,y). The only way I could think of is to compute the convex hull of the (x,y) coordinates of each object and use this as the outline of the object. This is clearly

Hey, all I am going to plot several 3-dimensional ellipsoids in R. For example, A is such a ellipsoid with mean u=[1 1 1]', covariance matrix C=[1 0 .5;0 1 .6;.5 .6 1]; So how can I plot such object in 3D space? Is there some function to achieve this? Thanks. Fred

Hi all, How do I visualize a contour of a tri-variate normal distribution? I just like to see the ellipsoid very much. I hope there is a easy way or existing method in R. Thank you a lot! Michael. [[alternative HTML version deleted]]

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

Dear All, The Minimum Volume Ellipsoid estimator ("cov.mve") was part of S+ but I cannot find it in R. Where can I find it? Why was it excluded? Cheers, Patrik Sweden

I am interested in making a random sample from a uniform distribution of points over the surface of the earth, using the WGS84 ellipsoid as a model for the earth. I know how to do this for a sphere, but would like to do better. I can supply random numbers, want latitude longitude pairs out. Can anyone point me at a solution? Thanks very much. -- Russell Senior ``I have nine fingers;

I am curious if there is code developed to plot confidence regions in 3D. The scatterplot3d function generates the plot I want, but would like an 3D equivalent to the data.ellipse function. Any help in this direction would be appreciated, be it theoretical, graphical, or otherwise. Melanie Edwards Senior Statistician Exponent 15375 SE 30th PL, Suite 250 Bellevue, WA 98007 Tel: (425) 519-8714

Hi, I would like to construct a transition matrix from a data frame with annual transitions of marked plants. plant<-c(1:6) class<-c("seed","seed", "seed", "veg", "rep", "rep") fate<-c("dead", "veg","veg","rep", "rep", "veg") trans<-data.frame(plant, class, fate)

Hello all, turns out i'm having a bad R week. I am at my wits end with a function that I am trying to write. When I run the lines of code outside of a function, I get the desired output. When I wrap the lines of code into a function it doesn't work as expected. Not sure what is going on here. I suspected that the syntax of the if statement with the for loop was the culprit, but when I