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%------------------------------------------------------- | 
				
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%    MMA求解程序 MMA.m | 
				
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%    本代码将原本的非线性问题线性近似,非凸问题凸近似,得到一系列 | 
				
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%    线性的、凸的子问题,再通过subsolv.m迭代求解这些线性的、凸的子问题最终找到最优值点 | 
				
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function [xmma,ymma,zmma,lam,xsi,eta,mu,zet,s,low,upp] = ... | 
				
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mmasub(m,n,iter,xval,xmin,xmax,xold1,xold2, ... | 
				
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f0val,df0dx,fval,dfdx,low,upp,a0,a,c,d) | 
				
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%    This function mmasub performs one MMA-iteration, aimed at | 
				
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%    solving the nonlinear programming problem: | 
				
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%    该函数进行MMA迭代,已解决符合以下形式的非线性(非凸)优化问题      | 
				
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%      Minimize  f_0(x) + a_0*z + sum( c_i*y_i + 0.5*d_i*(y_i)^2 ) | 
				
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%    subject to  f_i(x) - a_i*z - y_i <= 0,  i = 1,...,m | 
				
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%                xmin_j <= x_j <= xmax_j,    j = 1,...,n | 
				
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%                z >= 0,   y_i >= 0,         i = 1,...,m | 
				
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%   输入参数有: | 
				
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%   m    = 约束条件的数量 | 
				
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%   n    = 变量的个数 | 
				
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%  iter  = 迭代步数 | 
				
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%  xval  = 包含所有xj的向量 | 
				
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%  xmin  = 包含所有xj取值下限的向量 | 
				
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%  xmax  = 包含所有xj取值上限的向量 | 
				
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%  xold1 = 上次迭代产生的x_val | 
				
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%  xold2 = 上上次迭代产生的的xval | 
				
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%  f0val = 目标函数的现有值 | 
				
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%  df0dx = 包含目标函数对所有xj偏导数的列向量 | 
				
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%  fval  = 时约束函数fi值的列向量 | 
				
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%  dfdx  = x_j.fi对xj偏导数的矩阵 | 
				
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%  low   = 前一次迭代的渐近线下界 | 
				
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%  upp   = 前一次迭代的渐进线上界 | 
				
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%  引入下面四个量防止在初始值选择不恰当的形况下出现子问题不适定(没有结)的情况 | 
				
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%  a0    = a_0*z中的常系数a_0 | 
				
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%  a     = 用来存储a_i*z中系数 a_i的列向量 | 
				
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%  c     = 用来存储c_i*y_i中系数c_i的列向量  | 
				
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%  d     =用来存储0.5*d_i*(y_i)^2中系数d_i的列向量,d_i应该是一个足够大的数, | 
				
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%  可以证明当d_i足够大时y_i趋近于0    | 
				
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%输出的量: | 
				
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%  xmma  = 子问题求解出的xj的列向量 | 
				
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%  ymma  = 子问题求解出的yi的列向量 | 
				
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%  zmma  = z的标量 | 
				
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%  lam   = m个约束对应的拉格朗日乘子 | 
				
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%  xsi   = n个α<x_j对应的拉格朗日乘子 | 
				
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%  eta   = n个x_j<β对应的拉格朗日乘子 | 
				
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%   mu   = m个y_i<0对应的拉格朗日乘子。 | 
				
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%  zet   = z>0对应的拉格朗日乘子 | 
				
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%   s    = m个约束条件对应的松弛因子 | 
				
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%  low   = 本次求解的子问题对应的渐近线的下界 | 
				
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%  upp   = 本次求解的子问题对应的渐近线上界 | 
				
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% | 
				
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%epsimin = sqrt(m+n)*10^(-9);计算机精度的最小值 | 
				
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epsimin = 10^(-7); | 
				
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raa0 = 0.00001; | 
				
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move = 1.0; | 
				
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albefa = 0.1; | 
				
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asyinit = 0.5; | 
				
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asyincr = 1.2; | 
				
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asydecr = 0.7; | 
				
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eeen = ones(n,1); | 
				
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eeem = ones(m,1); | 
				
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zeron = zeros(n,1); | 
				
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 | 
				
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% Calculation of the asymptotes low and upp :计算渐近线的上下界 | 
				
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if iter < 2.5 | 
				
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  low = xval - asyinit*(xmax-xmin); | 
				
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  upp = xval + asyinit*(xmax-xmin); | 
				
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else | 
				
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  zzz = (xval-xold1).*(xold1-xold2); | 
				
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  factor = eeen; | 
				
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  factor(find(zzz > 0)) = asyincr; | 
				
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  factor(find(zzz < 0)) = asydecr; | 
				
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  low = xval - factor.*(xold1 - low); | 
				
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  upp = xval + factor.*(upp - xold1); | 
				
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  lowmin = xval - 10*(xmax-xmin); | 
				
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  lowmax = xval - 0.01*(xmax-xmin); | 
				
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  uppmin = xval + 0.01*(xmax-xmin); | 
				
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  uppmax = xval + 10*(xmax-xmin); | 
				
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  low = max(low,lowmin); | 
				
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  low = min(low,lowmax); | 
				
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  upp = min(upp,uppmax); | 
				
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  upp = max(upp,uppmin); | 
				
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end | 
				
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 | 
				
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% 计算设计变量的精确界限α和β | 
				
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 | 
				
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zzz1 = low + albefa*(xval-low); | 
				
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zzz2 = xval - move*(xmax-xmin); | 
				
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zzz  = max(zzz1,zzz2); | 
				
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alfa = max(zzz,xmin); | 
				
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zzz1 = upp - albefa*(upp-xval); | 
				
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zzz2 = xval + move*(xmax-xmin); | 
				
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zzz  = min(zzz1,zzz2); | 
				
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beta = min(zzz,xmax); | 
				
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 | 
				
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% 计算 p0, q0, P, Q 和 b. | 
				
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 | 
				
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xmami = xmax-xmin; | 
				
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xmamieps = 0.00001*eeen; | 
				
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xmami = max(xmami,xmamieps); | 
				
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xmamiinv = eeen./xmami; | 
				
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ux1 = upp-xval; | 
				
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ux2 = ux1.*ux1; | 
				
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xl1 = xval-low; | 
				
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xl2 = xl1.*xl1; | 
				
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uxinv = eeen./ux1; | 
				
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xlinv = eeen./xl1; | 
				
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% | 
				
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p0 = zeron; | 
				
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q0 = zeron; | 
				
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p0 = max(df0dx,0); | 
				
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q0 = max(-df0dx,0); | 
				
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%p0(find(df0dx > 0)) = df0dx(find(df0dx > 0)); | 
				
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%q0(find(df0dx < 0)) = -df0dx(find(df0dx < 0)); | 
				
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pq0 = 0.001*(p0 + q0) + raa0*xmamiinv; | 
				
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p0 = p0 + pq0; | 
				
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q0 = q0 + pq0; | 
				
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p0 = p0.*ux2; | 
				
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q0 = q0.*xl2; | 
				
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% | 
				
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P = sparse(m,n); | 
				
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Q = sparse(m,n); | 
				
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P = max(dfdx,0); | 
				
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Q = max(-dfdx,0); | 
				
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%P(find(dfdx > 0)) = dfdx(find(dfdx > 0)); | 
				
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%Q(find(dfdx < 0)) = -dfdx(find(dfdx < 0)); | 
				
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PQ = 0.001*(P + Q) + raa0*eeem*xmamiinv'; | 
				
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P = P + PQ; | 
				
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Q = Q + PQ; | 
				
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P = P * spdiags(ux2,0,n,n); | 
				
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Q = Q * spdiags(xl2,0,n,n); | 
				
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b = P*uxinv + Q*xlinv - fval ; | 
				
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% | 
				
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%%% 使用反演原对偶牛顿方法求解子问题 | 
				
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[xmma,ymma,zmma,lam,xsi,eta,mu,zet,s] = ... | 
				
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subsolv(m,n,epsimin,low,upp,alfa,beta,p0,q0,P,Q,a0,a,b,c,d); | 
				
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@ -0,0 +1,211 @@ | 
				
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%  子问题求解程序 subsolv.m | 
				
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% | 
				
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function [xmma,ymma,zmma,lamma,xsimma,etamma,mumma,zetmma,smma] = ... | 
				
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subsolv(m,n,epsimin,low,upp,alfa,beta,p0,q0,P,Q,a0,a,b,c,d);  | 
				
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% | 
				
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% 使用该函数求解MMA生成的子问题可以写成: | 
				
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%          | 
				
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% minimize   SUM[ p0j/(uppj-xj) + q0j/(xj-lowj) ] + a0*z + | 
				
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%          + SUM[ ci*yi + 0.5*di*(yi)^2 ], | 
				
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% | 
				
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% subject to SUM[ pij/(uppj-xj) + qij/(xj-lowj) ] - ai*z - yi <= bi, | 
				
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%            alfaj <=  xj <=  betaj,  yi >= 0,  z >= 0. | 
				
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% 然后使用拉格朗日的方法求解子问题的对偶问题        | 
				
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% Input:  m, n, low, upp, alfa, beta, p0, q0, P, Q, a0, a, b, c, d. | 
				
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% Output: xmma,ymma,zmma, slack variables and Lagrange multiplers. | 
				
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% | 
				
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een = ones(n,1); | 
				
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eem = ones(m,1); | 
				
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epsi = 1; | 
				
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epsvecn = epsi*een; | 
				
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epsvecm = epsi*eem; | 
				
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x = 0.5*(alfa+beta); | 
				
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y = eem; | 
				
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z = 1; | 
				
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lam = eem; | 
				
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xsi = een./(x-alfa); | 
				
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xsi = max(xsi,een); | 
				
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eta = een./(beta-x); | 
				
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eta = max(eta,een); | 
				
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mu  = max(eem,0.5*c); | 
				
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zet = 1; | 
				
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s = eem; | 
				
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itera = 0; | 
				
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 | 
				
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while epsi > epsimin | 
				
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  epsvecn = epsi*een; | 
				
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  epsvecm = epsi*eem; | 
				
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  ux1 = upp-x; | 
				
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  xl1 = x-low; | 
				
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  ux2 = ux1.*ux1; | 
				
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  xl2 = xl1.*xl1; | 
				
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  uxinv1 = een./ux1; | 
				
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  xlinv1 = een./xl1; | 
				
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 | 
				
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  plam = p0 + P'*lam ; | 
				
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  qlam = q0 + Q'*lam ; | 
				
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  gvec = P*uxinv1 + Q*xlinv1; | 
				
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  dpsidx = plam./ux2 - qlam./xl2 ; | 
				
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 | 
				
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  rex = dpsidx - xsi + eta; | 
				
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  rey = c + d.*y - mu - lam; | 
				
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  rez = a0 - zet - a'*lam; | 
				
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  relam = gvec - a*z - y + s - b; | 
				
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  rexsi = xsi.*(x-alfa) - epsvecn; | 
				
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  reeta = eta.*(beta-x) - epsvecn; | 
				
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  remu = mu.*y - epsvecm; | 
				
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  rezet = zet*z - epsi; | 
				
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  res = lam.*s - epsvecm; | 
				
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 | 
				
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  residu1 = [rex' rey' rez]'; | 
				
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  residu2 = [relam' rexsi' reeta' remu' rezet res']'; | 
				
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  residu = [residu1' residu2']'; | 
				
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  residunorm = sqrt(residu'*residu); | 
				
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  residumax = max(abs(residu)); | 
				
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 | 
				
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  ittt = 0; | 
				
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  while residumax > 0.9*epsi & ittt < 100 | 
				
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    ittt=ittt + 1; | 
				
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    itera=itera + 1; | 
				
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 | 
				
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    ux1 = upp-x; | 
				
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    xl1 = x-low; | 
				
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    ux2 = ux1.*ux1; | 
				
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    xl2 = xl1.*xl1; | 
				
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    ux3 = ux1.*ux2; | 
				
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    xl3 = xl1.*xl2; | 
				
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    uxinv1 = een./ux1; | 
				
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    xlinv1 = een./xl1; | 
				
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    uxinv2 = een./ux2; | 
				
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    xlinv2 = een./xl2; | 
				
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    plam = p0 + P'*lam ; | 
				
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    qlam = q0 + Q'*lam ; | 
				
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    gvec = P*uxinv1 + Q*xlinv1; | 
				
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    GG = P*spdiags(uxinv2,0,n,n) - Q*spdiags(xlinv2,0,n,n); | 
				
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    dpsidx = plam./ux2 - qlam./xl2 ; | 
				
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    delx = dpsidx - epsvecn./(x-alfa) + epsvecn./(beta-x); | 
				
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    dely = c + d.*y - lam - epsvecm./y; | 
				
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    delz = a0 - a'*lam - epsi/z; | 
				
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    dellam = gvec - a*z - y - b + epsvecm./lam; | 
				
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    diagx = plam./ux3 + qlam./xl3; | 
				
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    diagx = 2*diagx + xsi./(x-alfa) + eta./(beta-x); | 
				
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    diagxinv = een./diagx; | 
				
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    diagy = d + mu./y; | 
				
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    diagyinv = eem./diagy; | 
				
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    diaglam = s./lam; | 
				
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    diaglamyi = diaglam+diagyinv; | 
				
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 | 
				
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    if m < n | 
				
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      blam = dellam + dely./diagy - GG*(delx./diagx); | 
				
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      bb = [blam' delz]'; | 
				
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      Alam = spdiags(diaglamyi,0,m,m) + GG*spdiags(diagxinv,0,n,n)*GG'; | 
				
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      AA = [Alam     a | 
				
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            a'    -zet/z ]; | 
				
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      solut = AA\bb; | 
				
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      dlam = solut(1:m); | 
				
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      dz = solut(m+1); | 
				
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      dx = -delx./diagx - (GG'*dlam)./diagx; | 
				
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    else | 
				
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      diaglamyiinv = eem./diaglamyi; | 
				
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      dellamyi = dellam + dely./diagy; | 
				
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      Axx = spdiags(diagx,0,n,n) + GG'*spdiags(diaglamyiinv,0,m,m)*GG; | 
				
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      azz = zet/z + a'*(a./diaglamyi); | 
				
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      axz = -GG'*(a./diaglamyi); | 
				
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      bx = delx + GG'*(dellamyi./diaglamyi); | 
				
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      bz  = delz - a'*(dellamyi./diaglamyi); | 
				
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      AA = [Axx   axz | 
				
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            axz'  azz ]; | 
				
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      bb = [-bx' -bz]'; | 
				
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      solut = AA\bb; | 
				
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      dx  = solut(1:n); | 
				
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      dz = solut(n+1); | 
				
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      dlam = (GG*dx)./diaglamyi - dz*(a./diaglamyi) + dellamyi./diaglamyi; | 
				
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    end | 
				
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 | 
				
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    dy = -dely./diagy + dlam./diagy; | 
				
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    dxsi = -xsi + epsvecn./(x-alfa) - (xsi.*dx)./(x-alfa); | 
				
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    deta = -eta + epsvecn./(beta-x) + (eta.*dx)./(beta-x); | 
				
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    dmu  = -mu + epsvecm./y - (mu.*dy)./y; | 
				
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    dzet = -zet + epsi/z - zet*dz/z; | 
				
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    ds   = -s + epsvecm./lam - (s.*dlam)./lam; | 
				
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    xx  = [ y'  z  lam'  xsi'  eta'  mu'  zet  s']'; | 
				
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    dxx = [dy' dz dlam' dxsi' deta' dmu' dzet ds']'; | 
				
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 | 
				
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    stepxx = -1.01*dxx./xx; | 
				
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    stmxx  = max(stepxx); | 
				
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    stepalfa = -1.01*dx./(x-alfa); | 
				
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    stmalfa = max(stepalfa); | 
				
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    stepbeta = 1.01*dx./(beta-x); | 
				
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    stmbeta = max(stepbeta); | 
				
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    stmalbe  = max(stmalfa,stmbeta); | 
				
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    stmalbexx = max(stmalbe,stmxx); | 
				
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    stminv = max(stmalbexx,1); | 
				
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    steg = 1/stminv; | 
				
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 | 
				
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    xold   =   x; | 
				
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    yold   =   y; | 
				
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    zold   =   z; | 
				
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    lamold =  lam; | 
				
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    xsiold =  xsi; | 
				
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    etaold =  eta; | 
				
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    muold  =  mu; | 
				
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    zetold =  zet; | 
				
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    sold   =   s; | 
				
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 | 
				
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    itto = 0; | 
				
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    resinew = 2*residunorm; | 
				
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    while resinew > residunorm & itto < 50 | 
				
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    itto = itto+1; | 
				
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 | 
				
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    x   =   xold + steg*dx; | 
				
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    y   =   yold + steg*dy; | 
				
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    z   =   zold + steg*dz; | 
				
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    lam = lamold + steg*dlam; | 
				
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    xsi = xsiold + steg*dxsi; | 
				
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    eta = etaold + steg*deta; | 
				
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    mu  = muold  + steg*dmu; | 
				
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    zet = zetold + steg*dzet; | 
				
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    s   =   sold + steg*ds; | 
				
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    ux1 = upp-x; | 
				
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    xl1 = x-low; | 
				
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    ux2 = ux1.*ux1; | 
				
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    xl2 = xl1.*xl1; | 
				
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    uxinv1 = een./ux1; | 
				
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    xlinv1 = een./xl1; | 
				
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    plam = p0 + P'*lam ; | 
				
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    qlam = q0 + Q'*lam ; | 
				
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    gvec = P*uxinv1 + Q*xlinv1; | 
				
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    dpsidx = plam./ux2 - qlam./xl2 ; | 
				
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 | 
				
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    rex = dpsidx - xsi + eta; | 
				
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    rey = c + d.*y - mu - lam; | 
				
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    rez = a0 - zet - a'*lam; | 
				
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    relam = gvec - a*z - y + s - b; | 
				
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    rexsi = xsi.*(x-alfa) - epsvecn; | 
				
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    reeta = eta.*(beta-x) - epsvecn; | 
				
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    remu = mu.*y - epsvecm; | 
				
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    rezet = zet*z - epsi; | 
				
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    res = lam.*s - epsvecm; | 
				
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 | 
				
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    residu1 = [rex' rey' rez]'; | 
				
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    residu2 = [relam' rexsi' reeta' remu' rezet res']'; | 
				
			|||
    residu = [residu1' residu2']'; | 
				
			|||
    resinew = sqrt(residu'*residu); | 
				
			|||
    steg = steg/2; | 
				
			|||
    end | 
				
			|||
  residunorm=resinew; | 
				
			|||
  residumax = max(abs(residu)); | 
				
			|||
  steg = 2*steg; | 
				
			|||
  end | 
				
			|||
epsi = 0.1*epsi; | 
				
			|||
end | 
				
			|||
 | 
				
			|||
xmma   =   x; | 
				
			|||
ymma   =   y; | 
				
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zmma   =   z; | 
				
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lamma =  lam; | 
				
			|||
xsimma =  xsi; | 
				
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etamma =  eta; | 
				
			|||
mumma  =  mu; | 
				
			|||
zetmma =  zet; | 
				
			|||
smma   =   s; | 
				
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@ -0,0 +1,190 @@ | 
				
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%本文给定top3d(30,20,10,0.4,3,1.5) | 
				
			|||
function top3d(nelx,nely,nelz,volfrac,penal,rmin) | 
				
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% 定义循环参数 | 
				
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maxloop = 200;    % 最大迭代次数 | 
				
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tolx = 0.01;      % 终止条件(残差) | 
				
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displayflag = 1;  % 显示结构表示 | 
				
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% 材料的属性 | 
				
			|||
E0 = 1;           % 固体区域的杨氏模量 | 
				
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Emin = 1e-9;      % 非固体区域的杨氏模量,尽可能小但是为了避免奇异性一般不取0 | 
				
			|||
nu = 0.3;         % 泊松比 | 
				
			|||
% USER-DEFINED LOAD DOFs | 
				
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[il,jl,kl] = meshgrid(nelx, 0, 0:nelz);                 % Coordinates | 
				
			|||
loadnid = kl*(nelx+1)*(nely+1)+il*(nely+1)+(nely+1-jl); % Node IDs | 
				
			|||
loaddof = 3*loadnid(:) - 1;                             % DOFs | 
				
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% USER-DEFINED SUPPORT FIXED DOFs | 
				
			|||
[iif,jf,kf] = meshgrid(0,0:nely,0:nelz);                  % Coordinates | 
				
			|||
fixednid = kf*(nelx+1)*(nely+1)+iif*(nely+1)+(nely+1-jf); % Node IDs | 
				
			|||
fixeddof = [3*fixednid(:); 3*fixednid(:)-1; 3*fixednid(:)-2]; % DOFs | 
				
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% 有限元分析程序 | 
				
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nele = nelx*nely*nelz; | 
				
			|||
ndof = 3*(nelx+1)*(nely+1)*(nelz+1); | 
				
			|||
F = sparse(loaddof,1,-1,ndof,1); | 
				
			|||
U = zeros(ndof,1); | 
				
			|||
freedofs = setdiff(1:ndof,fixeddof); | 
				
			|||
KE = lk_H8(nu); | 
				
			|||
nodegrd = reshape(1:(nely+1)*(nelx+1),nely+1,nelx+1); | 
				
			|||
nodeids = reshape(nodegrd(1:end-1,1:end-1),nely*nelx,1); | 
				
			|||
nodeidz = 0:(nely+1)*(nelx+1):(nelz-1)*(nely+1)*(nelx+1); | 
				
			|||
nodeids = repmat(nodeids,size(nodeidz))+repmat(nodeidz,size(nodeids)); | 
				
			|||
edofVec = 3*nodeids(:)+1; | 
				
			|||
edofMat = repmat(edofVec,1,24)+ ... | 
				
			|||
    repmat([0 1 2 3*nely + [3 4 5 0 1 2] -3 -2 -1 ... | 
				
			|||
    3*(nely+1)*(nelx+1)+[0 1 2 3*nely + [3 4 5 0 1 2] -3 -2 -1]],nele,1); | 
				
			|||
iK = reshape(kron(edofMat,ones(24,1))',24*24*nele,1); | 
				
			|||
jK = reshape(kron(edofMat,ones(1,24))',24*24*nele,1); | 
				
			|||
% 过滤器 | 
				
			|||
iH = ones(nele*(2*(ceil(rmin)-1)+1)^2,1); | 
				
			|||
jH = ones(size(iH)); | 
				
			|||
sH = zeros(size(iH)); | 
				
			|||
k = 0; | 
				
			|||
for k1 = 1:nelz | 
				
			|||
    for i1 = 1:nelx | 
				
			|||
        for j1 = 1:nely | 
				
			|||
            e1 = (k1-1)*nelx*nely + (i1-1)*nely+j1; | 
				
			|||
            for k2 = max(k1-(ceil(rmin)-1),1):min(k1+(ceil(rmin)-1),nelz) | 
				
			|||
                for i2 = max(i1-(ceil(rmin)-1),1):min(i1+(ceil(rmin)-1),nelx) | 
				
			|||
                    for j2 = max(j1-(ceil(rmin)-1),1):min(j1+(ceil(rmin)-1),nely) | 
				
			|||
                        e2 = (k2-1)*nelx*nely + (i2-1)*nely+j2; | 
				
			|||
                        k = k+1; | 
				
			|||
                        iH(k) = e1; | 
				
			|||
                        jH(k) = e2; | 
				
			|||
                        sH(k) = max(0,rmin-sqrt((i1-i2)^2+(j1-j2)^2+(k1-k2)^2)); | 
				
			|||
                    end | 
				
			|||
                end | 
				
			|||
            end | 
				
			|||
        end | 
				
			|||
    end | 
				
			|||
end | 
				
			|||
H = sparse(iH,jH,sH); | 
				
			|||
Hs = sum(H,2); | 
				
			|||
% 迭代初始化 | 
				
			|||
x = repmat(volfrac,[nely,nelx,nelz]); | 
				
			|||
xPhys = x;  | 
				
			|||
loop = 0;  | 
				
			|||
change = 1; | 
				
			|||
 | 
				
			|||
m=1; | 
				
			|||
n=nele; | 
				
			|||
xmin=zeros (n, 1) ; | 
				
			|||
xmax=ones (n, 1) ; | 
				
			|||
xold1=x(:); | 
				
			|||
xold2=x(:); | 
				
			|||
low=ones(n, 1) ; | 
				
			|||
upp=ones(n, 1) ; | 
				
			|||
a0=1; | 
				
			|||
a=zeros (m, 1) ; | 
				
			|||
c_MMA=10000*ones (m, 1); | 
				
			|||
d=zeros (m, 1) ; | 
				
			|||
% 开始迭代 | 
				
			|||
while change > tolx && loop < maxloop | 
				
			|||
    loop = loop+1; | 
				
			|||
    % 有限元分析 | 
				
			|||
    sK = reshape(KE(:)*(Emin+xPhys(:)'.^penal*(E0-Emin)),24*24*nele,1); | 
				
			|||
    K = sparse(iK,jK,sK); K = (K+K')/2; | 
				
			|||
    U(freedofs,:) = K(freedofs,freedofs)\F(freedofs,:); | 
				
			|||
    % 定义目标函数与灵敏度分析 | 
				
			|||
    ce = reshape(sum((U(edofMat)*KE).*U(edofMat),2),[nely,nelx,nelz]); | 
				
			|||
    c = sum(sum(sum((Emin+xPhys.^penal*(E0-Emin)).*ce))); | 
				
			|||
    dc = -penal*(E0-Emin)*xPhys.^(penal-1).*ce; | 
				
			|||
    dv = ones(nely,nelx,nelz); | 
				
			|||
    % 对灵敏度进行过滤与投影,需要注意的是,并不能数学上证明对灵敏度进行过滤的 | 
				
			|||
    % 稳定性,如果出现不适定的情况可以尝试更改过滤为密度过滤 | 
				
			|||
    dc(:) = H*(dc(:)./Hs);   | 
				
			|||
    dv(:) = H*(dv(:)./Hs); | 
				
			|||
    % 移动渐近线法求解 | 
				
			|||
    xval  = x(:); | 
				
			|||
    f0val = c; | 
				
			|||
    df0dx = dc(:); | 
				
			|||
    fval  = sum(xPhys(:))/(volfrac*nele) - 1; | 
				
			|||
    dfdx  = dv(:)' / (volfrac*nele); | 
				
			|||
    [xmma, ~, ~, ~, ~, ~, ~, ~, ~, low,upp] = ... | 
				
			|||
    mmasub(m, n, loop, xval, xmin, xmax, xold1, xold2, ... | 
				
			|||
    f0val,df0dx,fval,dfdx,low,upp,a0,a,c_MMA,d); | 
				
			|||
    % 更新迭代变量 | 
				
			|||
    xnew     = reshape(xmma,nely,nelx,nelz); | 
				
			|||
    xPhys(:) = (H*xnew(:))./Hs; | 
				
			|||
    xold2    = xold1(:); | 
				
			|||
    xold1    = x(:); | 
				
			|||
    change = max(abs(xnew(:)-x(:))); | 
				
			|||
    x = xnew; | 
				
			|||
    % 输出结果 | 
				
			|||
    fprintf(' It.:%5i Obj.:%11.4f Vol.:%7.3f ch.:%7.3f\n',loop,c,mean(xPhys(:)),change); | 
				
			|||
    % 输出密度 | 
				
			|||
    if displayflag, clf; display_3D(xPhys); end  | 
				
			|||
end | 
				
			|||
clf; display_3D(xPhys); | 
				
			|||
end | 
				
			|||
 | 
				
			|||
 | 
				
			|||
% === 生成单元刚度矩阵 === | 
				
			|||
function [KE] = lk_H8(nu) | 
				
			|||
A = [32 6 -8 6 -6 4 3 -6 -10 3 -3 -3 -4 -8; | 
				
			|||
    -48 0 0 -24 24 0 0 0 12 -12 0 12 12 12]; | 
				
			|||
k = 1/144*A'*[1; nu]; | 
				
			|||
 | 
				
			|||
K1 = [k(1) k(2) k(2) k(3) k(5) k(5); | 
				
			|||
    k(2) k(1) k(2) k(4) k(6) k(7); | 
				
			|||
    k(2) k(2) k(1) k(4) k(7) k(6); | 
				
			|||
    k(3) k(4) k(4) k(1) k(8) k(8); | 
				
			|||
    k(5) k(6) k(7) k(8) k(1) k(2); | 
				
			|||
    k(5) k(7) k(6) k(8) k(2) k(1)]; | 
				
			|||
K2 = [k(9)  k(8)  k(12) k(6)  k(4)  k(7); | 
				
			|||
    k(8)  k(9)  k(12) k(5)  k(3)  k(5); | 
				
			|||
    k(10) k(10) k(13) k(7)  k(4)  k(6); | 
				
			|||
    k(6)  k(5)  k(11) k(9)  k(2)  k(10); | 
				
			|||
    k(4)  k(3)  k(5)  k(2)  k(9)  k(12) | 
				
			|||
    k(11) k(4)  k(6)  k(12) k(10) k(13)]; | 
				
			|||
K3 = [k(6)  k(7)  k(4)  k(9)  k(12) k(8); | 
				
			|||
    k(7)  k(6)  k(4)  k(10) k(13) k(10); | 
				
			|||
    k(5)  k(5)  k(3)  k(8)  k(12) k(9); | 
				
			|||
    k(9)  k(10) k(2)  k(6)  k(11) k(5); | 
				
			|||
    k(12) k(13) k(10) k(11) k(6)  k(4); | 
				
			|||
    k(2)  k(12) k(9)  k(4)  k(5)  k(3)]; | 
				
			|||
K4 = [k(14) k(11) k(11) k(13) k(10) k(10); | 
				
			|||
    k(11) k(14) k(11) k(12) k(9)  k(8); | 
				
			|||
    k(11) k(11) k(14) k(12) k(8)  k(9); | 
				
			|||
    k(13) k(12) k(12) k(14) k(7)  k(7); | 
				
			|||
    k(10) k(9)  k(8)  k(7)  k(14) k(11); | 
				
			|||
    k(10) k(8)  k(9)  k(7)  k(11) k(14)]; | 
				
			|||
K5 = [k(1) k(2)  k(8)  k(3) k(5)  k(4); | 
				
			|||
    k(2) k(1)  k(8)  k(4) k(6)  k(11); | 
				
			|||
    k(8) k(8)  k(1)  k(5) k(11) k(6); | 
				
			|||
    k(3) k(4)  k(5)  k(1) k(8)  k(2); | 
				
			|||
    k(5) k(6)  k(11) k(8) k(1)  k(8); | 
				
			|||
    k(4) k(11) k(6)  k(2) k(8)  k(1)]; | 
				
			|||
K6 = [k(14) k(11) k(7)  k(13) k(10) k(12); | 
				
			|||
    k(11) k(14) k(7)  k(12) k(9)  k(2); | 
				
			|||
    k(7)  k(7)  k(14) k(10) k(2)  k(9); | 
				
			|||
    k(13) k(12) k(10) k(14) k(7)  k(11); | 
				
			|||
    k(10) k(9)  k(2)  k(7)  k(14) k(7); | 
				
			|||
    k(12) k(2)  k(9)  k(11) k(7)  k(14)]; | 
				
			|||
KE = 1/((nu+1)*(1-2*nu))*... | 
				
			|||
    [ K1  K2  K3  K4; | 
				
			|||
    K2'  K5  K6  K3'; | 
				
			|||
    K3' K6  K5' K2'; | 
				
			|||
    K4  K3  K2  K1']; | 
				
			|||
end | 
				
			|||
% === 展示3D效果图 (ISO-VIEW) === | 
				
			|||
function display_3D(rho) | 
				
			|||
[nely,nelx,nelz] = size(rho); | 
				
			|||
hx = 1; hy = 1; hz = 1;            % 定义效果图的单元大小 | 
				
			|||
face = [1 2 3 4; 2 6 7 3; 4 3 7 8; 1 5 8 4; 1 2 6 5; 5 6 7 8]; | 
				
			|||
set(gcf,'Name','ISO display','NumberTitle','off'); | 
				
			|||
for k = 1:nelz | 
				
			|||
    z = (k-1)*hz; | 
				
			|||
    for i = 1:nelx | 
				
			|||
        x = (i-1)*hx; | 
				
			|||
        for j = 1:nely | 
				
			|||
            y = nely*hy - (j-1)*hy; | 
				
			|||
            if (rho(j,i,k) > 0.5)  % 定义展示出的密度阈值 | 
				
			|||
                vert = [x y z; x y-hx z; x+hx y-hx z; x+hx y z; x y z+hx;x y-hx z+hx; x+hx y-hx z+hx;x+hx y z+hx]; | 
				
			|||
                vert(:,[2 3]) = vert(:,[3 2]); vert(:,2,:) = -vert(:,2,:); | 
				
			|||
                patch('Faces',face,'Vertices',vert,'FaceColor',[0.2+0.8*(1-rho(j,i,k)),0.2+0.8*(1-rho(j,i,k)),0.2+0.8*(1-rho(j,i,k))]); | 
				
			|||
                hold on; | 
				
			|||
            end | 
				
			|||
        end | 
				
			|||
    end | 
				
			|||
end | 
				
			|||
axis equal; axis tight; axis off; box on; view([30,30]); pause(1e-6); | 
				
			|||
end | 
				
			|||
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		Reference in new issue