On 09/24/2010 10:41 PM, xin wei wrote: > > I am trying to reproduce the nice looking of Mandelbrot demonstrated by R > wiki page by the following code: > > library(caTools) # external package providing write.gif function > jet.colors = colorRampPalette(c("#00007F", "blue", "#007FFF", "cyan", > "#7FFF7F", > "yellow", "#FF7F00", "red", "#7F0000")) > m = 600 # define size > C = complex( real=rep(seq(-1.8,0.6, length.out=m), each=m ), > imag=rep(seq(-1.2,1.2, length.out=m), m ) ) > C = matrix(C,m,m) # reshape as square matrix of complex numbers > Z = 0 # initialize Z to zero > X = array(0, c(m,m,20)) # initialize output 3D array > for (k in 1:20) { # loop with 20 iterations > Z = Z^2+C # the central difference equation > X[,,k] = exp(-abs(Z)) # capture results > } > write.gif(X, "Mandelbrot.gif", col=jet.colors, delay=100)
Hmm, I couldn't be bothered with the caTools, but it looks fine for me with image(X[,,20],col=jet.colors(100)) Perhaps you need jet.colors(n) as well? > however, the gif file created by this looks much worse than what is shown on > R wiki page, see the comparison as follows (left one is what i created) > > http://r.789695.n4.nabble.com/file/n2591429/Picture1.png Save for the odd color scheme, the one on the left looks like a Mandelbrot set, the one on the right appears to be iteration 4. I couldn't find your original source for this on wiki.r-project.org? -- Peter Dalgaard Center for Statistics, Copenhagen Business School Phone: (+45)38153501 Email: pd....@cbs.dk Priv: pda...@gmail.com ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.