Getting a picture like this is pretty easy. e.g. x <- y <- seq(-5, 5, len = 200) X <- expand.grid(x = x, y = y) X <- transform(X, z = dnorm(x, -2.5)*dnorm(y) - dnorm(x, 2.5)*dnorm(y)) z <- matrix(X$z, nrow = 200)
persp(x, y, z, col = "lightgoldenrod", border = NA, theta = 30, phi = 15, ticktype = "detailed", ltheta = -120, shade = 0.25) You can vary things as you wish. I don't follow the remark about picking grid points at random for analysis, though. On simple, entirely deterministic things like this wouldn't you just be analysing the randomness that you inject into it by the choice process, effectively? Bill Venables. -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Laura Quinn Sent: Sunday, 29 January 2006 12:28 AM To: Duncan Murdoch Cc: r-help@stat.math.ethz.ch Subject: Re: [R] Creating 3D Gaussian Plot My apologies. With further apologies for the poor graphics, this link demonstrates the sort of 3d mesh which I am hoping to replicate - I would like to be able to replicate a number of these of varying intensity. Demonstrating different levels of potential via the "steepness" of the slopes. http://maxwell.ucdavis.edu/~electro/potential/images/steep.jpg I then wish to pick a number of grid points at random from the output to perform a further analysis upon. I hope this makes things a little clearer! Again, any help gratefully received, thank you. Laura Quinn Institute of Atmospheric Science School of Earth and Environment University of Leeds Leeds LS2 9JT tel: +44 113 343 1596 fax: +44 113 343 6716 mail: [EMAIL PROTECTED] On Sat, 28 Jan 2006, Duncan Murdoch wrote: > On 1/28/2006 8:55 AM, Laura Quinn wrote: > > Hello, > > > > I requested help a couple of weeks ago creating a dipole field in R but > > receieved no responses. Eventually I opted to create a 3d sinusoidal plot > > and concatenate this with its inverse as a means for a "next best" > > situation. It seems that this isn't sufficient for my needs and I'm really > > after creating a continuous 3d gaussian mesh with a "positive" and > > "negative" dipole. > > The names you're using don't mean anything to me; perhaps there just > aren't enough atmospheric scientists on the list and that's why you > didn't get any response. If you don't get a response this time, you > should describe what you want in basic terms, and/or point to examples > of it on the web. > > Duncan Murdoch > > > > > Can anyone offer any pointers at all? > > > > Laura Quinn > > Institute of Atmospheric Science > > School of Earth and Environment > > University of Leeds > > Leeds > > LS2 9JT > > > > tel: +44 113 343 1596 > > fax: +44 113 343 6716 > > mail: [EMAIL PROTECTED] > > > > ______________________________________________ > > R-help@stat.math.ethz.ch mailing list > > https://stat.ethz.ch/mailman/listinfo/r-help > > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html > > ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
