chunk = {
const sol = solution.sol;
const time = solution.t[0];
const tspan = [0.15,0.4];
const startIdx = time.reduce((sum, curr, i) => curr <= tspan[0] ? i : sum, 0);
const endIdx = time.reduce((sum,curr,i) => curr <= tspan[1] ? i : sum, 0);
const T1 = math.subset(time,math.index(math.range(startIdx,endIdx,true)));
const y1 = math.subset(sol,math.index(math.range(0,5),startIdx));
const chunk = await solve(mdl.odefun,T1,y1,mdl.opt);
return chunk
}