Beispiel - SAM - ETH Zürich

5
6 f u n c t i o n beat(alpha,filename)
7 % MATLAB function for numerical simulation of the Zeeman model
8 % (1.2.16) of heartbeat
9
0 i f (nargin < 2), filename = ’Heartbeat’; end
1 i f (nargin < 1), alpha = 2; end
2
3 % Model equations (right hand side)
4
5 beta = 0.1; % feedback parameter
6 l0 = 0; % length of relaxed muscle fibre
7
8 % Function handle to right hand side vector field
9 f_l = @(l,p) -(l.^3-alpha*l+p);
0 f_p = @(l,p) beta*(l-l0);
1 odefun = @(t,y) [f_l(y(1),y(2)); f_p(y(1),y(2))];
2
3 % Create plot of vector field
4 f i g u r e(’name’,’heartbeat field’); hold on;
5 [L,P] = meshgrid((-2.5:0.25:2.5),(-2.5:0.5:2.5));
6 quiver(L,P,f_l(L,P),f_p(L,P),1.5,’m-’);
7 axis([-2.5 2.5 -2.5 2.5]);
Numerische
Mathemtik
R. Hiptmair
rev 35327,
25. April
2011
1.2
p. 35