Printing syms / matlabFunction slow

Andrew Spielberg

2015 10 15

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7 次查看（30 天）

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function_and_jacobian.mat

Hi all,

I am having a lot of trouble trying to make my symbolic code go faster.

I am creating a complicated function f, and calculating its jacobian df. This goes at a reasonable pace, and I can save it to a file just fine. But when I try to use matlabFunction or even disp or fprintf, the system hangs and is unable to proceed further (even when matlabFunction is set to unoptimized). This is a major problem as I need to be able to do reasonably fast substitution.

The f vector is 24 elements, and the Jacobian is 24 x 78 (there are only 70 variables that show up here though, so this could be compressed down to 70 columns; I doubt this is the issue though).

I also know that certain elements which are simple work fine, but certain, more complicated elements of f and df cannot be displayed. I imagine they are very long, but since they are calculated just fine, it doesn't make sense to me that they cannot be transformed into a matlabFunction or displayed.

Even more bizarrely, I can substitute in for all my symbolic variables, but then the final display of the fully substituted f vector, or the conversion to double seems to take forever.

I'm attaching the file. What can I do to write out this file in a reasonable amount of time?

Thank you for your time.