How do I make this for loop

I have matrix 5x2

point = [105,308

162,470

200,150

470,135

570,390]

 x10 = point1(1)-point2(1);
 y10 = point3(2)-point2(2);
 x20 = point1(1)-point2(1);
 y20 = point3(2)-point2(2); 
 
 ang = atan2(abs(x10*y20-x20*y10),x10*y10+x20*y20)*180/pi;

by. point1 = previous point

point2 = center point

point3 = next point

I want to loop for finish 5 center point

[Geoff Hayes]

Nanny - why is x20 and x10 identical? y10 and y20 are the same too.

Consider replacing your arrays for each point with one array where each row represents a point rather than having individual variables for each point.

[Nanny Aberd]

oh sorry..

I mean

x10 = point1(1)-point2(1);

y10 = point1(2)-point2(2);

x20 = point3(1)-point2(1);

y20 = point3(2)-point2(2);

Answer 1

[Sulaymon Eshkabilov]

Hi Nanny,

Here is the loop based code of your problem:

point = [105,308
            162,470
            200,150
            470,135
            570,390];
        x=zeros(1, numel(point(:,1))-1);
        y=x;
        ang=x;
        for ii = 1:numel(point(:,1))-1
            x(ii) = point(ii,1)-point(ii+1, 1);
            y(ii) = point(ii,2)-point(ii+1, 2);
        end
        for jj=1:numel(x)-1
            ang(jj) = atan2(abs(x(jj)*y(jj+1)-x(jj+1)*y(jj)),x(jj)*y(jj)+x(jj+1)*y(jj+1))*180/pi;
        end

Note that in your formualtion there are some points (flaws w.r.t x10, x20, y10, y20...) as Geoff has pinpointed that was corrected.

Good luck.

[Nanny Aberd]

Thank you Sir.

In your code ang = [14 162 126 0]

but result that I want ang = [126 14 162 104 107]