Octave/Matlab: min of two vectors

问题

Let's take two vectors:

a = [1 ; 2; 3]
b = [0 ; 9 ; -5]

If I want minimum value of the vector and it's position I can simply:

[x, ix] = min(a)

I can also compare two vectors and get minimum values:

> min(a, b)
ans =

   0
   2
  -5

But it is impossible to get positions of min values of two vectors:

> [x, ix] = min(a, b)
x =

   0
   2
  -5

error: element number 2 undefined in return list

Why? How to get them? Is there a simple method?

回答1:

here's how to do that:

[v id]=min([a,b]')

回答2:

It's a matter of having the right insight:

[x,ix] = min([a b],[],2)

回答3:

You must think about what the intended output of ix is.

This shows you in which vector the minimum is:

ix=a<b;
x=a.*ix+b.*not(ix);

来源：https://stackoverflow.com/questions/20504954/octave-matlab-min-of-two-vectors