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我这儿也有一个相关的程序,算多重分形谱的,你可以看看
- %%
- % Author: Tegy J. Vadakkan
- % Date: 09/08/2009
- % input a binary image
- % the multifractal spectra is calculated based on the ideas in the paper by
- % Posadas et al., Soil Sci. Soc. Am. J. 67:1361-1369, 2003
- clc;
- clear all;
- close all;
- %%
- syms s;
- indata=inputdlg({'input photo'});
- a = imread(indata{1});
- [rows, cols] = size(a);
- figure;imshow(a);
- npix = sum(sum(a));
- %% calculates niL which is the number of pixels in the ith box of size L
- % ideas from boxcount.m by F. Moisy have been borrowed here
- width = rows;
- p = log(width)/log(2);
- max_boxes = power(rows,2)/power(2,2);
- nL = double(zeros(max_boxes,p));
- for g=(p-1):-1:0
- siz = 2^(p-g);
- sizm1 = siz - 1;
- index = log2(siz);
- count = 0;
- for i=1:siz:(width-siz+1)
- for j=1:siz:(width-siz+1)
- count = count + 1;
- sums = sum(sum(a(i:i+sizm1,j:j+sizm1)));
- nL(count,index) = sums;
- end
- end
- end
- %%
- qran = 1;
- logl = zeros(p,1);
- for l=1:p
- logl(l) = log(power(2,l));
- end
- %% normalized masses
- pL = double(zeros(max_boxes,p));
- for l=1:p
- nboxes = power(rows,2)/power(power(2,l),2);
- norm = sum(nL(1:nboxes,l));
- if(norm ~= npix)
- display('error');
- end
- for i=1:nboxes
- pL(i,l) = nL(i,l)/norm;
- end
- end
- %%
- %falpha, alpha
- for l=1:p
-
- count = 0;
- nboxes = power(rows,2)/power(power(2,l),2);
-
- for q = -qran:+0.1:qran
-
- %denominator of muiql
- qsum = 0.0;
- for i=1:nboxes
- if(pL(i,l) ~= 0)
- qsum = qsum + power(pL(i,l),q);
- end
- end
-
- fqnum = 0.0;
- aqnum = 0.0;
- smuiqL = 0.0;
- for i=1:nboxes
- if(pL(i,l) ~= 0)
- muiqL = power(pL(i,l),q)/qsum;
- fqnum = fqnum + (muiqL * log(muiqL));
- aqnum = aqnum + (muiqL * log(pL(i,l)));
- smuiqL = smuiqL + muiqL;
- end
- end
- if(uint8(smuiqL)~=1)
- display('error');
- end
-
- count = count + 1;
- fql(l,count) = fqnum;
- aql(l,count) = aqnum;
- qval(count) = q;
- end
- end
- %%
- % alpha_q
- for i=1:count
- line = polyfit(logl,aql(:,i),1);
- aq(i) = line(1);
- yfit = polyval(line,logl);
- sse = sum(power(aql(:,i)-yfit,2));
- sst = sum(power(aql(:,i)-mean(aql(:,i)),2));
- ar2(i) = 1-(sse/sst);
- end
- % f_q
- for i=1:count
- line = polyfit(logl,fql(:,i),1);
- fq(i) = line(1);
- yfit = polyval(line,logl);
- sse = sum(power(fql(:,i)-yfit,2));
- sst = sum(power(fql(:,i)-mean(fql(:,i)),2));
- fr2(i) = 1-(sse/sst);
- end
- figure;plot(qval,aq,'r:o',qval,fq,'g:o');grid on;
- h = legend('alpha(q)','f(q)',1);
- xlabel('q','FontSize',14);
- %gird on;
- figure;plot(aq,fq,'r:o');grid on;
- xlabel('alpha(q)','FontSize',14);
- ylabel('f(q)','FontSize',14);
- %%T=fmaxbnd(aq,2.00,4.00);
- %xt=solve(aq);
- %grid on;
- dy=diff(aq);
- xz=solve(dy);
- line=polyfit(aq,fq,2);
- pfit = polyval(line,aq);
- figure;plot(aq,fq,'r:o',aq,pfit,'g:o');grid on;
- h = legend('f(q)','Parabolic fit to f(q)',3);
- xlabel('alpha(q)','FontSize',14);
- %grid on;
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