82 lines
1.9 KiB
Matlab
82 lines
1.9 KiB
Matlab
% Exponente de Hurst en anillos de Saturno
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% Programa para estudiar exponente de Hurst y dimensión fractal de la estructura de anillos
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% Trabajo de Tesis - UNLP
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% Horacio Daniel Salomone
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% Start
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%Image reading
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AS1=imread('PIA22418.jpg');
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%Correct to a circle
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image(AS1), axis image;
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%Shows the figure
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subplot(2,2,1);
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imshow(AS1),title('Imágen Original-Cassini - Anillos de Saturno 5');
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%Cuts the figure and shows the cut
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AS2=imcrop;
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subplot(2,2,2);
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imshow(AS2),title('Imagen Recortada-Anillos de Saturno 5');
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%Loop to get the grayscale profiles
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%image size AS2
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sz=size(AS2);
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n=sz(1,1);
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%Intensity profile
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Perfil='Vectores Perfil Intensidad.txt';
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fid=fopen(Perfil,'a+');
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formatSpec='%9.5f\r\n';
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%Int vectors
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for i=1:n
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Int=improfile(AS2,[1 1018],[1 (0+i)]);
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%Recorta ceros del vector Int
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Int(isnan(Int))=0;
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%Int(Int==0)=[];
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l=1;
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while Int(l)==0
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l=l+1;
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end
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L=length(Int);
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r=1;
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while Int(L-r)==0
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r=r+1;
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end
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Int(L-r+1:L)=[];
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Int(1:l)=[];
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end
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%Hurst exponent calculation
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for i=1:120
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m=floor(L/(2*i));
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for j=1:i
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r=Int(1+(j-1)*m:j*m);
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M=mean(r);
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x=(r-M);
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V=cumsum(x);
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R(j)=max(V)-min(V);
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S(j)=std(r);
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end
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tau(i)=m;
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RS(i)=mean(R./S);
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end
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%Linear regression to obtain Hurst
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subplot (2,2,3);
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plot(log10(tau),log10(RS),'+')
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xlabel('log(\tau)','FontSize',12)
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ylabel('log(R/S)','FontSize',12)
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hold on
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q=polyfit(log10(tau),log10(RS),1);
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t=0.5:0.1:3;
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y=q(1)*t+(q(2));
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plot(t,y,'r','LineWidth',2)
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%text(1,2,['y =' num2str(q(1)),' x ' num2str(q(2))],'FontSize',12)
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hold off
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