/usr/share/octave/site/m/sundialsTB/cvodes/examples_ser/mcvsPleiades_non.m is in octave-sundials 2.5.0-3+b1.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 | function mcvsPleiades_non()
%mcvsPleiades_non - CVODES example problem (serial, nonstiff)
% Radu Serban <radu@llnl.gov>
% Copyright (c) 2005, The Regents of the University of California.
% $Revision: 1.1 $Date: 2007/10/26 16:30:48 $
neq = 28;
t0 = 0.0;
tout = 3.0;
y0 = zeros(neq,1);
y0(1) = 3.0;
y0(2) = 3.0;
y0(3) = -1.0;
y0(4) = -3.0;
y0(5) = 2.0;
y0(6) = -2.0;
y0(7) = 2.0;
y0(8) = 3.0;
y0(9) = -3.0;
y0(10) = 2.0;
y0(13) = -4.0;
y0(14) = 4.0;
y0(20) = 1.75;
y0(21) = -1.5;
y0(25) = -1.25;
y0(26) = 1.0;
options = CVodeSetOptions('RelTol', 1.0e-7,...
'AbsTol', 1.0e-7,...
'StopTime',tout,...
'MaxNumSteps',2000);
CVodeInit(@rhsfn, 'Adams', 'Functional', t0, y0, options);
% Loop in one-step mode
t = t0;
i = 0;
while t < tout
i = i+1;
[status,t,y] = CVode(tout,'OneStep');
time(i) = t;
xx(:,i) = y(1:7);
yy(:,i) = y(8:14);
end
% Display solver statistics
Stats = CVodeGetStats
% Free solver memory
CVodeFree;
% Plot body trajectories
colors = ['k','b','r','g','c','y','m'];
figure;
for i = 1:7
plot(xx(i,:),yy(i,:),colors(i));
hold on;
end
legend('Body 1','Body 2','Body 3','Body 4','Body 5','Body 6','Body 7');
title('Body Trajectories');
xlabel('x');
ylabel('y');
grid on;
axis square;
% ===========================================================================
function [yd, flag, new_data] = rhsfn(t, y, data)
% Right-hand side function
for i = 1:7
sumx = 0.0;
sumy = 0.0;
for j = 1:7
mj = j;
rij = (y(i)-y(j))^2 + (y(i+7)-y(j+7))^2;
rij32 = rij^(3/2);
if j ~= i
sumx = sumx + mj*(y(j)-y(i))/rij32;
sumy = sumy + mj*(y(j+7)-y(i+7))/rij32;
end
end
yd(i+14) = sumx;
yd(i+21) = sumy;
end
for i = 1:14
yd(i) = y(i+14);
end
flag = 0;
new_data = [];
return
% ===========================================================================
function [J, flag, new_data] = djacfn(t, y, fy, data)
% Dense Jacobian function
neq = 28;
J = zeros(neq,neq);
for i = 1:14
J(i,14+i)=1.0;
end
for i = 2:7
mi=i;
for j = 1:i-1
mj = j;
rij = (y(i)-y(j))^2+(y(i+7)-y(j+7))^2;
rij32 = rij^(3/2);
rij52 = rij^(5/2);
fjh = (1.0-3.0*(y(j)-y(i))^2/rij)/rij32;
J(i+14,j) = mj*fjh;
J(j+14,i) = mi*fjh;
fjh = (1.0-3.0*(y(j+7)-y(i+7))^2/rij)/rij32;
J(i+21,j+7) = mj*fjh;
J(j+21,i+7) = mi*fjh;
fjh = -3.0*(y(j)-y(i))*(y(j+7)-y(i+7))/rij52;
J(i+14,j+7) = mj*fjh;
J(j+14,i+7) = mi*fjh;
J(i+21,j) = mj*fjh;
J(j+21,i) = mi*fjh;
end
end
for i = 1:7
sumxx = 0.0;
sumxy = 0.0;
sumyy = 0.0;
for j = 1:7
if j ~= i
sumxx = sumxx + J(i+14,j);
sumxy = sumxy + J(i+14,j+7);
sumyy = sumyy + J(i+21,j+7);
end
end
J(i+14,i) = -sumxx;
J(i+14,i+7) = -sumxy;
J(i+21,i) = -sumxy;
J(i+21,i+7) = -sumyy;
end
flag = 0;
new_data = [];
return
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