a b/combinedDeepLearningActiveContour/minFunc/logistic/LogisticDiagPrecond.m 

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function [m] = LogisticHv(v,w,X,y)





  
  

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% v(feature,1) - vector that we will apply diagonal preconditioner to





  
  

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% w(feature,1)





  
  

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% X(instance,feature)





  
  

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% y(instance,1)





  
  

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sig = 1./(1+exp(-y.*(X*w)));





  
  

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% Compute diagonals of Hessian





  
  

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sig = sig.*(1-sig);





  
  

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for i = 1:length(w)





  
  

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   h(i,1) = (sig.*X(:,i))'*X(:,i);





  
  

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end





  
  

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% Apply preconditioner





  
  

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m = v./h;





  
  

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% Exact preconditioner





  
  

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%H = X'*diag(sig.*(1-sig))*X;





  
  

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%m = H\v;