%Blahblah Uncle Don's T-Line using Cylindrical Coordinates %First build A Matrix for 3 circles divided into 8 pies romax=3; %romax is the total ro values we take simax=8; %simax is the divisions of the coordinate system siz = romax*simax; %size of the A matrix A = eye(siz)*0; %this sucka is just the matrix with no values in yet. It's reset to zero B = zeros(siz,1); %And now let's build the functions to calculate the constants for our %cylindrical coordinate finite difference method calculations delro = 0.005; %5 cm delsi = pi/4; %psi increment in radians ronot = 0.01; %the circle layer distance from origin %inner node ~closer to origin Ao = 1-delro/2/ronot; %outer node ~towards edge Bo = 1+delro/2/ronot; %counterclockwise node and clockwise node Co = (delro/ronot/delsi)^2; %original node ~the center node Do = -(2+2*(delro/ronot/delsi)^2); %nitty gritty ~crunchin numbers by each ronot ronot = 0.01; Ao = 1-delro/2/ronot; Bo = 1+delro/2/ronot; Co = (delro/ronot/delsi)^2; Do = -(2+2*(delro/ronot/delsi)^2); %node 1 B(1) = -65*Ao; %inner node known constant will be moved to B matrix A(1,9) = Bo*0; %outer node A(1,2) = Co; %counterclockwise node A(1,8) = Co; %clockwise node A(1,1) = Do; %center node %node 2 B(2) = -65*Ao; A(2,10) = Bo; A(2,3) = Co; A(2,1) = Co; A(2,2) = Do; %node 3 B(3) = -65*Ao; A(3,11) = Bo; A(3,4) = Co; A(3,2) = Co; A(3,3) = Do; %node 4 B(4) = -65*Ao; A(4,12) = Bo; A(4,5) = Co; A(4,3) = Co; A(4,4) = Do; %node 5 B(5) = -65*Ao; A(5,13) = Bo; A(5,6) = Co; A(5,4) = Co; A(5,5) = Do; %node 6 B(6) = -65*Ao; A(6,14) = Bo; A(6,7) = Co; A(6,5) = Co; A(6,6) = Do; %node 7 B(7) = -65*Ao; A(7,15) = Bo; A(7,8) = Co; A(7,6) = Co; A(7,7) = Do; %node 8 B(8) = -65*Ao; A(8,16) = Bo; A(8,1) = Co; A(8,7) = Co; A(8,8) = Do; ronot = 0.015; Ao = 1-delro/2/ronot; Bo = 1+delro/2/ronot; Co = (delro/ronot/delsi)^2; Do = -(2+2*(delro/ronot/delsi)^2); %node 9 A(9,1) = Ao; B(9,17) = Bo*0; A(9,10) = Co; A(9,16) = Co; A(9,9) = Do*0; %node 10 A(10,2) = Ao; A(10,18)= Bo; A(10,11) = Co; A(10,9) = Co; A(10,10) = Do; %node 11 A(11,3) = Ao; A(11,19) = Bo*0; A(11,12) = Co; A(11,10) = Co; A(11,11) = Do; %node 12 A(12,4) = Ao; A(12,20) = Bo; A(12,13) = Co*0; A(12,11) = Co; A(12,12) = Do; %node 13 A(13,21) = Ao*0; A(13,5) = Bo; A(13,14) = Co; A(13,12) = Co; A(13,13) = Do*0; %node 14 A(14,6) = Ao; A(14,22) = Bo; A(14,15) = Co; A(14,13) = Co*0; A(14,14) = Do; %node 15 A(15,7) = Ao; A(15,23) = Bo*0; A(15,16) = Co; A(15,14) = Co; A(15,15) = Do; %node 16 A(16,8) = Ao; A(16,24) = Bo; A(16,9) = Co*0; A(16,15) = Co; A(16,16) = Do; ronot = 0.02; Ao = 1-delro/2/ronot; Bo = 1+delro/2/ronot; Co = (delro/ronot/delsi)^2; Do = -(2+2*(delro/ronot/delsi)^2); %node 17 A(17,9) = Ao*0; %A(17,25) = Bo*0; A(17,18) = Co; A(17,24) = Co; A(17,17) = Do*0; %node 18 A(18,10) = Ao; A(18,26) = Bo*0; A(18,19) = Co*0; A(18,17) = Co*0; A(18,18) = Do; %node 19 A(19,11) = Ao; %A(19,27) = Bo*0; A(19,20) = Co; A(19,18) = Co; A(19,19) = Do*0; %node 20 A(20,12) = Ao; %A(20,28) = Bo*0; A(20,21) = Co*0; A(20,19) = Co*0; A(20,20) = Do; %node 21 A(21,13) = Ao*0; %A(21,29) = Bo*0; A(21,22) = Co; A(21,20) = Co; A(21,21) = Do*0; %node 22 A(22,14) = Ao; %A(22,30) = Bo*0; A(22,23) = Co*0; A(22,21) = Co*0; A(22,22) = Do; %node 23 A(23,15) = Ao; %A(23,31) = Bo*0; A(23,24) = Co; A(23,22) = Co; A(23,23) = Do*0; %node 24 A(24,16) =Ao; %A(23,32) = Bo*0; A(24,17) = Co*0; A(24,23) = Co*0; A(24,24) = Do; V=A\B; V=V(1:siz,1) Phi = reshape(V,romax,simax); tline(1:5,1:8)=0; hole(1,1:8)=65; edge(5,1:8)=0; tline(2:4,1:8)=Phi; tline(1,1:8)=hole; tline figure;image(Phi'); axis image; set(gcf,'color','w'); figure;contour(Phi',romax*simax); grid on; set(gcf,'color','w');