Matlab question:
Suppose $Q\subset\mathbb{R}^3$ and $x\in\mathbb{R}^3-\ Q$
Is there a matlab command that will give me the vector/vectors $u$ in $Q$ s.t. $||u-x||_2^2$ is minimal.

Question

Matlab question:
Suppose $Q\subset\mathbb{R}^3$ and $x\in\mathbb{R}^3-\ Q$ 
Is there a matlab command that will give me the vector/vectors $u$ in $Q$ s.t. $||u-x||_2^2$ is minimal.

zzr0ck3r · Answer

I.E is there a projection command?

kmeis002 · Answer

Quick clarification, what is the 2 super and subscript?

zzr0ck3r · Answer

norm 2 squared, or euclids norm squared
$(x_1-u_1)^2+.....+(x_i-u_i)^2$ in this example i = 3

kmeis002 · Answer

If you are just looking for projection commands, there are a couple that have been written by users, but I dont think there is one standard in its library.

zzr0ck3r · Answer

ahh

zzr0ck3r · Answer

I could write one, but I'm sure there are faster ones

kmeis002 · Answer

Most of the ones I've found with a quick search just use the NORM and dot product command with a dimensional check, nothing too fancy.