fern.rar_Fern matlab_barnsley fern_fern_probability

function fern(N) % This routine draws Barnsley's fern % The transformations for the fern are each in the form % T(x,y = (a*x+b*y+e, c*x+d*y+f). If the probability that a % particular transformation T is selected is p, you can characterize % each transformation by providing the values of % a,b,c,d,e,f, and p, in that order. % % T1 -> 0,0,0,.16,0,0,.01 % T2-> .85,.04,-.04,.85,0,1.6,.85 % T3-> .2,-.26,.23,.22,0,1.6,.07 % T4-> -.15,.28,.26,.24,0,.44,.07 % % INPUT % N -> The number of iterations. % Close all existing figure windows. Delete this line % if you do not want this action. close all % Initialize figure window and axes fig1=figure; ax1=axes; % Initialize some space to hold the sequence of points % X1, X2, ..., XN X=zeros(N,2); % The initial value X1 = [0.5,0.5]. X(1,:)=[0.5,0.5]; % X(1,:) means "first row, every column." % The main loop where the iterations are performed. for k=1:N-1 r=rand; if r<.01 X(k+1,:)=T(X(k,:),0,0,0,.16,0,0); elseif r<.86 X(k+1,:)=T(X(k,:),.85,.04,-.04,.85,0,1.6); elseif r<.93 X(k+1,:)=T(X(k,:),.2,-.26,.23,.22,0,1.6); else X(k+1,:)=T(X(k,:),-.15,.28,.26,.24,0,.44); end end plot(X(:,1),X(:,2),'.','markersize',1) % The transformation T axis off function U=T(X,a,b,c,d,e,f) U=zeros(1,2); U(1)=a*X(1)+b*X(2)+e; U(2)=c*X(1)+d*X(2)+f;