Re: mandelbrot in version 7 & Ruskeepaa version 3

*To*: mathgroup at smc.vnet.net*Subject*: [mg120446] Re: mandelbrot in version 7 & Ruskeepaa version 3*From*: "DaleJenk" <dale.jenkins8 at deletegooglemail.com>*Date*: Fri, 22 Jul 2011 19:47:45 -0400 (EDT)*References*: <j0aivf$ghq$1@smc.vnet.net> <j0b9l4$jjj$1@smc.vnet.net>

Many thanks - to you, and to the people who replied to me privately. "Oleksandr Rasputinov" <oleksandr_rasputinov at hmamail.com> wrote in message news:j0b9l4$jjj$1 at smc.vnet.net... > There is a space missing between I and y in the expression mandelbrot[x + > Iy] (should be mandelbrot[x + I y]). Also, you should omit the semicolon > after DensityPlot, otherwise the plot will not be shown. > > Incidentally, tabulating the values and then plotting them with ArrayPlot > is faster for this example than using DensityPlot. That is, > > ArrayPlot@Table[ > mandelbrot[x + I y], > {y, -1.5, 1.5, 0.005}, {x, -2.0, 1.0, 0.005} > ] > > On Fri, 22 Jul 2011 02:15:27 +0100, DaleJenk > <dale.jenkins8 at deletegooglemail.com> wrote: > >> I bought Mathematica 7 Home Edition last year. I'm trying to plot the >> Mandelbrot Set following the instructions in Ruskeepaa's Mathematica >> Navigator version 3. I'm getting an error message. >> >> Here's what I am introducing: >> >> mandelbrot = Compile[{{c,_Complex}}, >> Module[{z=0+0I, n=0}, While[Abs[z]<2 && n<50, z=z^2+c; n++]; n]]; >> >> DensityPlot[mandelbrot[x+Iy], {x,-2,1},{y,-1.5,1.5}, PlotPoints->200, >> Mesh->False, FrameTicks->{{-2,-1,0,1},{-1,0,1}}]; //Timing >> >> I get the message: >> >> CompiledFunction::cfsa: >> Argument -1.99998 + Iy at position 1 should be a machine-size complex >> number. >> >> Where am I going wrong? >> >> Thanks. >> >