How do I find closest values between 2 matrices?

Lets say I have defined values like this:

true_ang = [-40 -20];

After passing through an algorithm, my output are polynomial roots such as this:

rts = roots(cc)
rts = 6×1 complex
 -0.048729197855492 - 1.282493377891869i
 -0.029583698890964 - 0.778607069086665i
  0.409971042365044 + 0.917186264825464i
  0.406190666466556 + 0.908728816636128i
 -0.461769455823652 + 0.941122806650886i
 -0.420194118738174 + 0.856388969382348i

This is followed by converting to angle form:

all_angs = -asin(angle(rts)/pi)*180/pi
all_angs = 6×1
  30.803049614608504
  30.803049614608490
 -21.481431164796401 (this)
 -21.481431164797179
 -40.180359320706906 (this)
 -40.180359320706934

My question is, how do I automatically obtain the closest values from all_angs to true_ang (which I've denoted at the sideas "this")? Note that the order of the results can be random.

Answer 1

[KSSV]

Read about knnsearch

true_ang = [-40 -20]; 
all_angs = [ 30.803049614608504
  30.803049614608490
 -21.481431164796401 
 -21.481431164797179
 -40.180359320706906 
 -40.180359320706934] ;

idx = knnsearch(all_angs,true_ang') ;
all_angs(idx)

[Murdifi Bin Muhammad]

Wow I didn't know such function exist. Thanks for the help.

Answer 2

[Stephen23]

Using basic MATLAB only (i.e. without knnsearch from the Statistics Toolbox):

>> true_ang = [-40,-20];
>> all_angs = [30.803049614608504,30.803049614608490,-21.481431164796401,-21.481431164797179,-40.180359320706906,-40.1803
59320706934];
>> [~,idx] = min(abs(true_ang - all_angs(:)),[],1);
>> all_angs(idx)
ans =
  -40.180359320706906  -21.481431164796401