MATLAB: Find the Argmin of a vector

#argmin-vector

Help:

Let x be a vector and B_1…B_p p matrices,

I look for the index j* of the matrix such that

||B_j*||=min ||B_i x||, (||.||=norm)

How do I write this with matlab?

You should have avoided naming the variables that way, and should have used (for example) a cell array.

Indeed. Here's an example of how to do it when that is the case.

Bcell={rand(5), rand(5), rand(5), rand(5)}; %B1,...,Bp   p=4
[~, jstar] = min(cellfun(@(B) norm(B*x),Bcell)) %EDITED

% B original binary matrix
% B_ new binary matrix 
B_ = ~B;