Is there any MATLAB toolbox that can find the local MAX of a piece-wise multi-variable function?

I have a piece-wise function f(x,y,z) which is not linear necessarily. Is there any toolbox that can find the local maximums of this function in MATLAB?

Thanks

Answer 1

[Gouri Chennuru]

Hi Niloufar,

You can use “islocalmin” function in order to find the local minima which returns a logical array whose elements are 1 (true) when a local minimum is detected in the corresponding element of an array, table, or timetable.

Similarly you can make use of “islocalmax” function in order to find the local maxima which returns a logical array whose elements are 1 (true) when a local maximum is detected in the corresponding element of an array, table, or timetable.

You can also use “findpeaks” returns a vector with the local maxima (peaks) of the input signal vector, data which is available in the signal processing toolbox.

Hope this Helps!

[Niloufar Mirzavand Boroujeni]

Thanks for the help, Gouri. By the way, my problem size is large and I my function is discontinuos, I found simulated aneealing solver, a ggod option to so this.

[Walter Roberson]

islocalmin() would be for vectors, not for functions.

Answer 2

[Bruno Luong]

fmincon and friends if you have the toolbox.

[Niloufar Mirzavand Boroujeni]

Thanks for the help Burno.

[Walter Roberson]

fmincon cannot handle discontinuities over the range it is testing.

You can, though, test one range at a time, if the boundaries of the ranges can reasonably be determined.

[Bruno Luong]

Piecewise function is not necessary discontinue, e.g., a spline.