How can I get a position of a value from an array, and the same position in another array?

How can I get a position of a single value from an array, and the same position in another array?

function [next_point, calculated_L] = pick_next_point(x_c, y_c, points_to_check, x, y)
 
    next_point = points_to_check;                            % sets next_point to the points_to_check
    L = sqrt((x_c - x).^2 + (y_c - y).^2);                   % grabs the distance between the current point and all given points
    
    calculated_L = L(points_to_check);                       % grabs the L of the points that haven't been visited 
    calculated_L = min(calculated_L);                        % takes the smallest vector (smallest distance)
    

    disp(calculated_L);
    disp(next_point);
        
end

with:

x_c = 2

y_c = -1

x = [2,7,3,5,-2]

y = [1,5,1,5,-2]

points_to_check = [2,3,5]

I want to get the position of the second value in "calculated_L = L(points_to_check);" (postion of value will change) (those values being == [7,3,-2])

and then want to find the value in the same position in points_to_check

Answer 1

[KSSV]

You have straight functions to achieve this. REad about ismember and knnsearch.

[Raife Jones]

How would you use knnsearch in my case?

and doesn't ismember just determines if one array has the same numbers as the second?

[KSSV]

x = [2,7,3,5,-2] ; 
y = [1,5,1,5,-2] ; 
[c,ia] = ismember(x,[2 3 5]) ;
y(c)