How can I set the step size to a constant value for the ode solver in simbiology?

I know that I can set the MaxStep in the simulation settings for a sbiomodel:

as in:

set(cs1.SolverOptions, 'MaxStep', 0.1);

% Initialize configset for analysis run.
cs = getconfigset(m1, 'default');

% RUNSIMULATION simulate SimBiology model, m1.

% Run simulation.
data = sbiosimulate(m1, cs, [], []);

How can I set the step size to a constant number instead of just a maximum?

Answer 1

[Arthur Goldsipe]

Hi Scott,

SimBiology does not support a true fixed step solver, but if your real goal is to have simulation at specific times (for example, uniformly spaced times), then that is possible.

If you are using MATLAB R2012a or later, you can directly specify what times the simulation should record using the new OutputTimes property on the SolverOptions. For example,

cs = getconfigset(m1, 'default');
set(cs.SolverOptions, 'OutputTimes', 0:1:10)
data = sbiosimulate(m1, cs, [], []);

will give you simulation results at times 0:1:10.

If you are using an earlier version of SimBiology, you can resample the simulation results at the desired time. For example,

cs = getconfigset(m1, 'default');
data1 = sbiosimulate(m1, cs, [], []);
data2 = resample(data1, 0:1:10, 'pchip');

will resample the results at times 0:1:10 using the pchip interpolation method.

-Arthur