similar to: fractals

Well, I started playing with fractals in R, and wrote a function to generate de Mandelbrot set, which might be of interest to some people ########################################################################### # Mandelbrot set ########################################################################### mandelbrot <- function(x = c(-3.0, 1.0), # x coordinates y =

Dear R People: Here is an interesting question(I think) Suppose I want to calculate Centered Moving Averages; i.e. x[1] <- ( sum(y[1:12]) )/12 x[2] <- ( sum(y[2:13]) )/12 and so on. Of course, this is easily done through loops. However, I have been trying to do this more elegantly, but have failed. I have tried things like j1 <- 1:109 j2 <- 12:120 x[1:109] <- ( sum( y[j1:j2])

Hello R People: Suppose I create a function, x.e, via the fix command: > x.e <- fix(x.e) When I type in x.e, the function code appears, along with the name/number of the environment. However, if I create a function, y.e, and source it in, when I type in y.e, the function code only displays(no environment). Why is this, please? (It's not a bug....I just wondered). I am using

Dear R People: I have the source for R version 1.1.1 on a UNIX system alpha-dec-osf4. The ./configure works fine. When I do the make, it works fine until it tries to build the package tcklc. I get an error of Tk_Saf_Init not identified Then it kicks out. Any suggestions, please? Thanks! Sincerely, Erin M. Hodgess, Ph.D. Associate Professor Department of Computer and Mathematical Sciences

Dear R People: Do any of the linear model or regression function calculate the Durbin-Watson test statistic for serial correlation, please? I found the hat matrix, studentized residuals, and so on, but no D-W. Thanks so much! Sincerely, Erin M. Hodgess, Ph.D. Associate Professor Department of Computer and Mathematical Sciences University of Houston - Downtown One Main Street Houston, TX 77002

Dear R People: Is there a function for exponential smoothing, please? R version 1.4.1 for Windows. Thanks in advance! Have a great weekend! Sincerely, Erin Hodgess Associate Professor Department of Computer and Mathematical Sciences University of Houston - Downtown 1 Main Street Houston, TX 77002 mailto: hodgess at uhddx01.dt.uh.edu

Dear R People: I am drawing graphs for a College Algebra class. I would like to have the x and y axes, along with the lines that I am plotting. So I leave off the axes, and use xlim and ylim. Then I add my abline(v=0). However, I would like to have tick marks on the abline. How would I do that, please? Thanks in advance! Sincerely, Erin M. Hodgess, Ph.D. Associate Professor Department of

Dear R people is there a module for quality control, please? X bar charts, and such? perhaps a contributed package? Thanks in advance! Erin Hodgess Associate Professor Department of Computer and Mathematical Sciences University of Houston - Downtown 1 Main Street Houston, TX 77002 mailto: hodgess at uhddx01.dt.uh.edu

Dear R People: Here is a very simple question, please: I have a data frame with the state name, state division, and population. Note: state division is something like Atlantic, Mountain, etc. I want to produce a table with the state division and the total of the populations for the states within that division. I've been messing with "table" but so far, no luck. This is R1.3.1,

Hello, Although your message is not very explicit about the structure of your data frame, I think you can get what you want by using a combination of the function "split" and the "apply" functions family: apply, lapply and sapply. If you provide a more detailed organization of your data frame, perhaps we can give to you a more wiser advice. Thanks, Carlos. P.S: By the way,

Dear R People: Here is a non-R probability question, please: There is a problem, originally posed from an American game show, called "Let's Make a Deal." A contestant makes a selection of one door, from Doors 1 through 3. He or she knows that there are 2 goats and 1 car behind those doors. Once the contestant makes the selection, say Door 2, then the host, Monty Hall, tells him

Hello, R People: How do I change the size of a graph, please? I tried par(cin=c(8.5,11)) and it said that Warning message: parameter "cin" can't be set in: par(args) > par(fin=c(8.5,11)) > plot(xa,ya) Error in plot.new() : Figure region too large Also, can I set for portrait or landscape, please? Thanks in advance! Erin M. Hodgess, Ph.D. Associate Professor Department

Dear R People: I'm trying to use the predict command on an arima0 object. I do the following: xm.arma <- arima0(xm2,order=c(1,0,1)) predict(xm.arma,n.ahead=2) and I get the message: Error in round(x, digits) : Non-numeric argument to mathematical function Any ideas what the problem might be, please? R version 1 4 1 on Windows. Thanks in advance! Sincerely, Erin Hodgess Associate

Dear R People: I have R Version 0.90.1 for UNIX (binary) and the Windows version from a binary distribution as well. I would like to look at the source code for the C program setup_starma in the ts library. How would I find that, please? Thanks in advance. Sincerely, Erin M. Hodgess, Ph.D. Assistant Professor Department of Computer and Mathematical Sciences University of Houston - Downtown

Dear R People: Suppose I put in the following: > w1 <- expression(2*x) > v1 <- expression(x^2) and I want to get the derivative of w1 * v1 with respect to x > D(w1*v1,"x") Error in w1 * v1 : non-numeric argument to binary operator Is there a way around this, please? Thanks in advance! Sincerely, Erin M. Hodgess, Ph.D. Associate Professor Department of Computer and

Dear R People: Is there a library for Multivariate time series, please? For some reason, I'm thinking that Dr. Paul Gilbert may have one? R Version 1.6.2 (i've updated!) for Windows Thanks so much! Sincerely, Erin Hodgess University of Houston - Downtown mailto: hodgess at uhddx01.dt.uh.edu

Hi all, just a quick link for those interested in a tutorial about implementing Mandelbrot fractals in LLVM assembly: http://blog.zanopia.org/2010/09/understanding-llvm-assembly-with-fractals-part-i.html Cheers, Giorgio Regni

Dear R People: At one time, there were packages called fractal and Fractal, respectively, which had different functions. I can't seem to find Fractal any more. Does it still exist somewhere, please? Thanks in advance for any help! Sincerely, Erin -- Erin Hodgess Associate Professor Department of Computer and Mathematical Sciences University of Houston - Downtown mailto: erinm.hodgess

Dear R People: I have a few questions about multiple comparisons and contrasts for ANOVA, please. I've tried some things but with no success. Suppose I have a completely randomized design, and I want to have the contrast \mu_1 - 0.5 \mu_2 - 0.5 \mu_2 How do I set that up, please? I used the C command, and ran aov, but the results were identical to those with no contrasts. Also, is there

Dear R People: I have a question about a "sorting" problem, please. I have a vector xx: > xx [1] -2.0 1.4 -1.2 -2.2 0.4 1.5 -2.2 0.2 -0.4 -0.9 and a vector of breaks: > xx.y [1] -2.2000000 -0.9666667 0.2666667 1.5000000 I want to produce another vector z which contains the number of the class that each data point is in. for instance, xx[1] is between xx.y[1] and