matlabFunction very slow

Hi,

I am using the symbolic math toolbox to generate analytical derivatives of single valued function in approximately 190 unknowns. This works all fine (within 3 min). However, if I use matlabFunction to generate an m-file consisting of the first-order conditions, this actually takes hours... I am even more concerned by the fact that the cpu-usage is only around 0.2 percent (I have eight cores, so it would be still below 2 percent for one core).

Why is matlabFunction so slow compared to fprintf? Is it just because it tries to optimize the output? Why does matlabFunction use only a negligible fraction of the cpu?

Thanks for your answers, Best, Martin

[Walter Roberson]

Related: http://www.mathworks.com/matlabcentral/answers/12491-why-is-matlabfunction-so-slow

Answer 1

[the cyclist]

What is the memory usage like? If you need to use virtual memory, the whole thing will slow down dramatically.

Answer 2

[Martin]

Actually, it uses virtual memory in a modest way. That was my first thought as well. This should not be the problem: matlabFunction is always quite slow even for small functions. Is there a way to write the function unoptimized?