MATLAB: How should i go about solving a set of ODEs for a set of data points? I would like to automate it as much as possible.

MATLABode45

Currently I am using the ode45 solver, with my input parameters being a vector of length 7, which is two separate terms being length 6 and 1. My equations has a variable which needs to be solved for set amount of time and then it changes.
How do i go about doing this?
%so what im doing is,
tspan = [0 20];
options = odeset('MaxStep',0.05,'RelTol',1e-8,'AbsTol',1e-9);
stress1 = [525 450 385 200 150];
stress2 = [630 560 475 332 200];
for ii =1:length(stress1) % i intend to repeat this process for stress2
odeIp = [0 0 0 0 0 0 0 1 ii]';
odeOp = ode45(@odefn,tspan,odeIp,options);
Var2 = odeOp( : , 7); %gives me Solrequired
VarRequied(:,ii) = Var2;
end
%in the function im im using If statement to choose my initial conditions
function dOdeOp = odefn(t,odeIp)
%input constants and splitting the terms
stress1 = [525 450 385 200 150];
stress2 = [630 560 475 332 200];
D0 = odeIp(7,1);
alpha = odeIp(1:6);
var = odeIp(8,1);
sigvar = odeIp(9,1);
if var ==1
    mSig = 0;
else
    mSig = 100;
end
if var ==1
    aSig = stress1(sigvar);
else
    aSig = stress2(sigvar);
end
equat = mSig + aSig*sin(omega*t);
dequat = aSig*omega*cos(omega*t);
%solve set of equations outputs Sol1,SolRequired
% solving a bunc of equtions to get Sol1 which is an array of 1x6 and SolRequired
% which makes up the 7 column
dOdeOp1 =[Sol1;SolRequired];
dOdeOp2 = [dOdeOp1;var];
dOdeOp = [dOdeOp2;sigvar];
currently only the last two coulmns of my output vector is obtaining values, which shouldnt be the case

Best Answer

Please see my earlier comments.
From the behavior you describe, it looks like Sol1 and SolRequired are returned empty from what ever solver produces them. In that case your last few lines of code would result in a dOdeOp that has only two elements (var and sigvar).
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