Lookup Table for Multi Variable Implicit Function or MATLAB Function

In order to call the precalculated values of a multi-variable function can I use the Simulink n-D Lookup Table or is there a MATLAB function to do that? In part of my script I need to access an output of the function F(x,y,z)-unknown function- knowing the values for x,y,z. My cell arrays look like this:

x   y   z     F
7   3   15   0.003
8   4   19   0.04
7   5   12   0.09
.
.
.

So I have the values for x,y,z and F columns independently. I know I can write an IF statement for x=x0,y=y0,z=z0 and find the row index and F but I am trying to use a faster way without having to go to through for/if loops. speed is an issue. Is there a MATLAB function for that? Thanks

Answer 1

[Sean de Wolski]

Sounds like a use for scattered or gridded interpolants:

http://www.mathworks.com/help/releases/R2014a/matlab/interpolation-1.html

[Orion]

Thanks for the link but I guess my question is simpler than that. I am still using the known integer values for x,y,z. nothing different than the recorded values. like if all four columns are stored in table T, then I want T(7,3,15) returns 0.003.

[Sean de Wolski]

Oh. Then use ismember with the 'rows'__ option

x = [1 2; 3 4; 5 6]
idx = ismember(x,[3 4],'rows')
F(idx)