boundquad1.m

来自「MATLAB二维电阻抗断层成像算法!用于医学成像,里面包括有限元剖分正问题,及反」· M 代码 · 共 33 行

function int=boundquad1(g);

%boundquad1 Computes the boundary integral of one quadratic basis functions
% Function int=boundquad1(g) calculates the boundary integral
% of one quadratic basis function over the curve defined by the coordinates in g.
%
% INPUT
%
% g = global coordinates of the integration curve
%
% OUTPUT
%
% int = value of the integral



w=[1/2,1/2];
ip=[1/2-1/6*sqrt(3),1/2+1/6*sqrt(3)];
int=0;
 for ii=1:2
  S=[2*ip(ii)^2-3*ip(ii)+1; ...
     -4*ip(ii)^2+4*ip(ii); ...
     2*ip(ii)^2-ip(ii)];
  dJt=sqrt((g(1,1)*(4*ip(ii)-3)+g(2,1)*(4-8*ip(ii))+g(3,1)*(4*ip(ii)-1))^2+ ...
            (g(1,2)*(4*ip(ii)-3)+g(2,2)*(4-8*ip(ii))+g(3,2)*(4*ip(ii)-1))^2);
  int=int+w(ii)*S*dJt;
 end