Output of file : PDE contained in archive : MATLAB.ZIP
//Conductivity example.
//Parameters
n //number of terms in solution
m //number of boundary points
//initialize operation counts
flop = <0,0>;
//initialize variables
m1 = round(m/3);
m2 = m - m1;
pi = 4.0*atan(1.0);
//generate points in Cartesian coordinates
//right hand edge
for i = 1:m1, x(i) = 1; y(i) = (1-rho)*(i-1)/(m1-1);
//top edge
for i = m2+1:m, x(i) = (1-rho)*(m-i)/(m-m2-1); y(i) = 1;
//circular edge
for i = m1+1:m2, t = (pi/2)*(i-m1)/(m2-m1+1); ...
x(i) = 1-rho*sin(t); y(i) = 1-rho*cos(t);
//convert to polar coordinates
for i = 1:m-1, th(i) = atan(y(i)/x(i)); ...
r(i) = sqrt(x(i)**2+y(i)**2);
th(m) = pi/2; r(m) = 1;
//generate matrix
//Dirichlet conditions
for i = 1:m2, for j = 1:n, k = 2*j-1; ...
a(i,j) = r(i)**k*cos(k*th(i));
//Neumann conditions
for i = m2+1:m, for j = 1:n, k = 2*j-1; ...
a(i,j) = k*r(i)**(k-1)*sin((k-1)*th(i));
//generate right hand side
for i = 1:m2, b(i) = 1;
for i = m2+1:m, b(i) = 0;
//solve for coefficients
c = A\b
//compute effective conductivity
c(2:2:n) = -c(2:2:n);
sigma = sum(c)
//output total operation count
ops = flop(2)
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### 3 Responses to “Category : Science and EducationArchive   : MATLAB.ZIPFilename : PDE”

1. Very nice! Thank you for this wonderful archive. I wonder why I found it only now. Long live the BBS file archives!

2. This is so awesome! 😀 I’d be cool if you could download an entire archive of this at once, though.

3. But one thing that puzzles me is the “mtswslnkmcjklsdlsbdmMICROSOFT” string. There is an article about it here. It is definitely worth a read: http://www.os2museum.com/wp/mtswslnk/