How do I incrementize ode solver outputs after solution?

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Z Yerby 2019-6-24

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编辑： Z Yerby 2019-6-24

I'm trying to take ode45 output and adjust it so the independent variable (time in this instance) has consistent increments e.g. make the step sizes 1 second instead of being all over the place as they are. What I have so far is that I know there an intersection calculator so I was thinking I could use a loop to place a line at each second mark and figure the intersection from that. Doing so is a really round about and messy way; I don't like it. I want to perform this incrementization post-solve so that I don't damage my solution. Is there an effecient way of doing this?

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Answer 1

Steven Lord 2019-6-24

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You could specify the tspan input to the ODE solver as 0:yourEndingTime. If you do this the solver will return the value of the solution at the specified times. [Internally it will use whatever timesteps it needs to solve the problem to the appropriate precision, but it will then return the value of the solution at those time steps.]

If you do need to solve this after solving with a tspan input that consists of just the starting and ending time, pass the solution structure returned by the ODE solver into deval.