[R] Fractals with R

[Atte Tenkanen]

Now problems with plot-command...

I try to plot Julia set and the algorithm works, if the points are drawn during the loop. But if I want to save the values first to the matrix and then afterwards plot them at once, the picture is distorted. What's wrong with the plot-command? I think the PointsMatrix is ok?

-Atte

C=-0.7-0.4i # Complex parameter, connected to coordinate of the Mandelbrot set in a complex plane.
Limits=c(-2,2)
z=0+0i
MaxIter=60
cl=colours()
Step=seq(Limits[1],Limits[2],by=0.01)
PointsMatrix=array(0,dim=c(length(Step)*length(Step),3))
a1=0

for(x in Step)
{
	for(y in Step)
	{
		z1=x+y*1i
		n=0
		z=z1
		while(n<MaxIter & abs(z)<2)
		{
			z=z^2+C
			n=n+1
		}
		if(abs(z)<2) colour=1
		else colour=n*10
		#points(z1, pch=".", col=cl[colour]) # This works!
 
               # But this doesn't!
                a1=a1+1
                PointsMatrix[a1,]=c(x,y,colour)
	}
}

#???
plot(PointsMatrix[,1], PointsMatrix[,2], xlim=Limits, ylim=Limits, col=cl[PointsMatrix[,3]], pch=".")

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> Atte Tenkanen wrote:
> > Hi,
> > 
> > That is of counter for web page. Do you get some pop-up windows?
> > 
> > 
> > Atte
> 
> Hi Atte,
>