How do I save the entire workspace through an ode function call?

I am working in command line mode --- with nodisplay, nojwm, nosplash, and no desktop mode

I would like to record how variables change during a call to ode45. I want the entire sequence rather than just the final values.

I see the save command but what is the format of the file produced?

Answer 1

[Jan]

The format of the save command is explained in detail here:

doc save

The description is not clear: "record how variables change". Which variables? What does "during a call" exactly mean? Inside of before versus after?

[Walt]

Hello and thanks. I am calculating using ode45. There will many calls to a "integration" function. It is values of various variables here that I wish to capture. e.g. ode45 calls fff(.m) several times and the sparse matrix A is created (by fff) once during each call. I would like to capture the sequence of values A takes on.

Answer 2

[James Tursa]

If A is not too large and you don't have too many iterations, you might consider just storing them in memory and then saving later. E.g., put the A iterations in a global cell array with each iteration being one of the cells. Ordinarily I might have suggested a 3D array to hold the results, but that is not going to work very well if A is sparse (data copying issues with each iteration).

Answer 3

[Walt]

Thanks again.

Making A "global" is a good idea; thanks. Is there a way to cause sparse A to be saved in a readable form in a file; Will I have to create the fprintf iteration to get this? or is there a system call.v currently A is approximately 5x5 with about 10 calls to fff(.m) A may have only 6 or 7 entries.

[Walt]

Is there a way to have the workspace saved (in easily readable format) in a file while a short run-time matlab main function executes.