initialfield.m

解决麦克斯韦的matlab源文件

function y = initialfield(x,omega,phioffs)
% Initial electric field
% omega = 3/2*pi for L-shaped domain
% omega = pi/2 for square

ep = pi/omega;
phi = atan2(x(2),x(1)) + phioffs;
rad = norm(x);

if (rad < eps), rad = eps; end

p = rad^(ep)*cos(ep*phi);
cp = ep*rad^(ep-1)*(cos(ep*phi)*[-x(2);x(1)] + ...
		    sin(ep*phi)*[x(1);x(2)])/rad;

if ((abs(x(1)) < 0.5) & (abs(x(2)) < 0.5))
  f = 1;
  cf = [0;0];
elseif ((abs(x(1)) >= 0.5) & (abs(x(2)) < 0.5))
  f = sin(pi*x(1))^2;
  cf = pi*[0; sin(2*pi*x(1))];
elseif ((abs(x(1)) < 0.5) & (abs(x(2)) >= 0.5))
  f = sin(pi*x(2))^2;
  cf = pi*[-sin(2*pi*x(2)) ; 0];
else 
  f = (sin(pi*x(1))*sin(pi*x(2)))^2;
  cf = pi*[-(sin(pi*x(1))^2)*sin(2*pi*x(2)); ...
	sin(2*pi*x(1))*(sin(pi*x(2))^2)];
end

y = f*cp + p*cf;