iso_f_smooth.sci

用来实现三维阻抗及光学断层成像重建的matlab程序

function [sm1]=iso_f_smooth(%simp,w)
sm1=[];
[nargout,nargin] = argn(0)
//function [sm1] = iso_f_smooth(simp,w);
// 
//Calculates a first order discrete Gaussian smoothing operator
// 
// 
// 
//simp = The simplices matrix.
//w    = smoothing weight, w=1...k, default value = 1
//sm1  = The first order smoothing regulariser. 
 
if nargin<2 then
  w = 1;
end
 
if w<0 then
  error('Weight must be possitive');
end
 
ndsrch = [%simp,(1:size(%simp,1))'];
 
 
//!! Unknown function spalloc ,the original calling sequence is used
sm1 = spalloc(size(%simp,1),size(%simp,1),20*size(%simp,1));
 
 
for i = 1:size(ndsrch,1)
   
  t_id = ndsrch(i,1:size(%simp,2));
   
  Xsimp = [];
  //The vector of simp indices that share a node with simp(i)
   
   
  //! unknown arg type, using mtlb_length 
  for j = 1:mtlb_length(t_id)
     
    t_nd = t_id(j);
     
    X1 = find(%simp(:,1)==t_nd)';
    X2 = find(%simp(:,2)==t_nd)';
    X3 = find(%simp(:,3)==t_nd)';
    X4 = find(%simp(:,4)==t_nd)';
     
     
    //!! Unknown function unique ,the original calling sequence is used
    XX = unique([X1;X2;X3;X4]);
     
    Xsimp = [Xsimp;XX];
  end
   
   
  //!! Unknown function setdiff ,the original calling sequence is used
  Xdif = setdiff(Xsimp,i);
  sm1(i,Xdif) = -1/w;
   
  //! mtlb_sum(sm1(i,:)) may be replaced by 
  //!     sum(sm1(i,:)) if sm1(i,:)is a vector
  //!     sum(sm1(i,:),1) if sm1(i,:)is a matrix
  sm1(i,i) = abs(mtlb_sum(sm1(i,:)));
   
end
 
 
 
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
// This is part of the EIDORS suite.
// Copyright (c) N. Polydorides 2001
// Copying permitted under terms of GNU GPL
// See enclosed file gpl.html for details.
// EIDORS 3D version 1.0
// MATLAB version 5.3 R11
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%