heaviside.m is slow

I am using heaviside.m inside the right hand side function for ode45. There is a for loop within the right hand side function that gets evaluated at each time point the integrator takes a step into. I profiled the result because the code has gotten much slower. This is where I learned that heaviside.m is very slow.

We can use logical indexing to replace the heaviside.m function. I did this and this is much faster but not as fast as it should be... Unfortunately, the for loop cannot be vectorized because the system is a linear system with a non linear right hand side vector.

Do you think the logical indexing is the fastest way to map a real number to 0 or 1, depending on it sign, in MATLAB? Also, could there be any speed up with the for-loop, if we cannot get rid of it?

Thanks a lot for your help!

Sincerely,

Tae

[Mike Croucher]

Hi Tae

You are much more likely to get an answer if you post your code. Help us help you: Post your code - (mathworks.com)

We can't promise anything of course but it definitely helps.

Best Wishes,

Mike

[Taehun Kim]

Thanks Mike for sharing the article! I do really appreciate the MATLAB Answers community! These people are the best!