Inner for loop working - problems with outer for loop

I managed to advance with a problem I was having and am looking for some advice on structuring my outer for loop. My inner loop works correctly. I want to repeat the 11 calculations 6 times using a different height (value of h) for each iteration. On the iterations of the J loop h increases to it's original value + 2*h. POI in the K loop depends on h. Should it be within the nested loop?

h = 0.5985;

GroundDistance = 18.75;

SouthAngle = 57;

TreeHeight = 14;

POI = TreeHeight-h;

BuildingElevationAng = atand(POI/GroundDistance);

a=0.265;
TreeLengthRHS = 15.89+a;
h = 0.5985;
X(1,1)=h;

    for k = 2:6;
      X(k) = X(k-1) + (X(1)*2);
    end

for J = 1:6

h=h+(2*h);

     for K  = 1:11

     TreeLengthTest(K) = TreeLengthRHS + (2*(K-1)*a);
     TreeLengthLHS = 75 - TreeLengthTest(K);

     AngleBx(K) = atand(TreeLengthLHS/GroundDistance);
     AngleCx(K) = atand(TreeLengthTest(K)/GroundDistance); %wasTreeLengthRHS
     DistanceAx(K) = GroundDistance/cosd(SouthAngle);
     DistanceBx(K) = GroundDistance/cosd(AngleBx(K));
     DistanceCx(K) = GroundDistance/cosd(AngleCx(K));
     AltAngleA(K) = atand(POI/DistanceAx(K));
     AltAngleB(K) = atand(POI/DistanceBx(K));
     AltAngleC(K) = atand(POI/DistanceCx(K));

     AzimuthA = 0;
     AzimuthB = (-AngleBx)-SouthAngle;
     AzimuthC = AngleCx-SouthAngle;

     end

end

Any help is greatly appreciated.

Answer 1

[Image Analyst]

I don't see POI defined anywhere - does it use global variables or something? Is it a function or a variable? Anyway, if POI does not depend on K at all, then it can be pulled out of the K loop and be assigned in the h loop. If POI is a function, then do something like

thisPOI = POI;

inside the h loop but outside the K loop, and then use thisPOI everywhere you see POI in the K loop.

[P]

I have updated to include the full script as POI and other variables were omitted for readability. Thanks.

[Image Analyst]

I don't see how POI is supposed to change with J or K. And you no longer have an h loop.

[P]

Updated with h inside the J loop. Should POI still not reference the h value from earlier in the script/inside the J loop for the recalculation? New to MATLAB so please forgive if this sounds unclear. I've just used J as the dummy variable i.e the variable that says 'do this 6 times'.

[Image Analyst]

What happens if you step through it with the debugger (like I'd have to do if I were to debug it for you)? What do you learn?

[P]

I haven't debugged it mainly because I didn't know about the debugger since i've only started using matlab recently. I was looking at the values in the variable window to try and determine what was going on. In some cases h was reaching a value in the 100's and none of my 1x11 vectors were increased to 1x66. I even laid out the calculations in microsoft Excel to cross check. Thanks.

[Image Analyst]

Oh no! That's going to be a major major problem! Debugging via Answers forum discussions is a very slow way to debug a program. I suggest you take a look at http://blogs.mathworks.com/videos/2012/07/03/debugging-in-matlab/ which will get you up to speed in just a few minutes - far faster than the hour it took me to respond to your last reply. It's something you're going to have to learn eventually anyway, so might as well take the 5 minutes now and do it. No one can get very far in MATLAB without learning how to debug their own code.