MATLAB: Help in writing a function

differential equationsdifferential equations systemsystem

Hi everyone, I need to write a function to solve this system:
Until now all I can came up with was:
 function dz = control1(v,z,parameters)
% gammaT=parameters(1);
phi_0=parameters(2);
psi_0=parameters(3);
psi_c0=parameters(4);
B=parameters(5);
Lc=parameters(6);
W=parameters(7);
H=parameters(8);
C = 0;
gammaT_max = 0.9;
gammaT_min = 0.61;
A = (gammaT_max - gammaT_min)/2; %amplitude
b = gammaT_max - ((gammaT_max - gammaT_min)/2);
hertz = 50;
w=hertz*2*pi;
gammaT = @(t) A*sin(w*t)+b 
dz = zeros(2,1);
dz(1)=(1/(4*B*B*Lc))*(z(2)-gammaT(v)*(z(1))^0.5);
psi_c=psi_c0+H*(1+1.5*(z(2)/W-1)-0.5*(z(2)/W-1).^3);
dz(2) =(1/Lc)*(psi_c-z(1));
 end
which is obviously wrong since gammaT = @(t) A*sin(w*t)+b shoouldn't be define this way.
I think gammaT should be written in that way but the time in the argument of the sin should be rearranged in some way I don't know

Best Answer

‘which is obviously wrong since gammaT = @(t) A*sin(w*t)+b shoouldn't be define this way.’
Why? It appears to be coded correctly with respect to the posted image. It’s being evaluated with respect to your independent variable ‘v’, that appears to be correct. If it should actually be a different variable (such as time), it would be necessary to define the time in the context of the existing variables. We would need more information in order to help you with that.
For what it’s worth, the function runs without error for me using: 
parameters = rand(8,1);
and: 
[V,Z] = ode45(@(v,z)control1(v,z,parameters), [0 10], rand(2,1));
figure
plot(V, Z)
grid
.
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