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ODE15s - help please

ODE15s - help please

ODE15s - help please

I am trying to use the ODE15s to solve a set of stiff differential equations. the problem is:
Given y"=A, where A is an output from another function and is a finite number.
the solver is within a for loop for evaluating the values at time t+dt in every iteration.

I am solving for y using the syntax:

for t=0:dt:5

dy=ode15s(ode15s('soluda',[t t+dt],[0],[],A);

y=ode15s(ode15s('solua',[t t+dt],[0],[],dy);


the functions are:
function dy=soluda(g,y,flag,A)

function y=solua(g,y,flag,dy)


Is my syntax correct?
I get a solution but I have my doubts regarding the initial values at time '0' = 0 and the timespan I have in the code [t+dt]

Please help.

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