Lookup tables in Matlab

Dear All,

I want to use lookup tables in Matlab to replace computation of complicated functional relations. The goal is to speed up computations. In the SIMULINK environment, I found a set of tools that perfectly matches my needs: the blocks '1-D lookup table', '2-D lookup table', 'Prelookup' etc.

My questions are: - Is a comparable set of tools or functions available in MATLAB? So far I have found approaches using interp1. Is this the fastest approach or are there better ways? And: So far I have not found a way to pass to interp1 the index of the previous search as search entry point (which speeds up things when changes between calls are small). - Can I use the mentioned SIMULINK blocks in Matlab? And if yes: how, and will it makes sense if computational speed is an issue?

Uwe

Answer 1

[Walter Roberson]

http://www.mathworks.com/matlabcentral/fileexchange/43325-quicker-1d-linear-interpolation--interp1qr

[Uwe Ehret]

Thanks for pointing me to interp1qr! I tested interp1q (build-in Matlab function), interp1qr, and nakeinterp1 (a .mex function provided in http://www.mathworks.com/matlabcentral/newsreader/view_thread/258413). - interpqr is ~ 3x faster than interp1q - nakeinterp1 is ~ 10x faster than interp1q --> If there are no other alternatives, I will use the .mex function for now. Uwe