Need Help using for and running a loop

Basically i have the following code;

for k = 1:357;
    j = 357:1;

   hold on    
  %%3D Elipsoid
  % 
   x0 = jhkmag{k}(:,1)-jhkmag{j}(:,1);
  hold on
   y0 = dffmag{k}(:,1) - dffmag{j}(:,1);
  hold on
   z0 = dffmag{k}(:,2) - dffmag{j}(:,2);
   rccm{k} = sqrt((0.5)*((x0{k}.^2)+(y0{k}.^2) + (z0{k}.^2)));
  hold on
  end 
  end

basically this code should calculate an ellipsoidal and calculate the distance to each point. But I cant get the loop to work it keeps saying that there is a bad cell reference, I really cant get this figured out. The next thing I need it to do is count to the nearest 15 data points, then compare that rccm on a different set of data results. I have no idea how to do this either pleeeeeaaase help

Answer 1

[the cyclist]

If you type

>> dbstop if error

before executing your code, then the code execution will halt when MATLAB hits the line causing the error, and you will be in debug mode. Then, you can go into the editor and see exactly what's happening, in terms of loop variable value, etc., to get more insight into the error.

After you track it down, you can type

>> dbclear if error

to disable the automatic stopping on error.

[Matt]

it says that its in the line starting with x0 this is what it says;

Bad cell reference operation.

Error in LoopGraphs (line 10) x0 = jhkmag{k}(:,1)-jhkmag{j}(:,1);

10 x0 = jhkmag{k}(:,1)-jhkmag{j}(:,1);

i still don't really understand why it wont do it though

[per isakson]

What does

    K>> jhkmag{j}

and

    K>> jhkmag{k}

show?

Answer 2

[Walter Roberson]

j = 357:1; defines j as empty. If you want j to count down, use a negative increment,

j = 357:-1:1;

Also, the spacing you used,

for k = 1:357;
    j = 357:1;

tends to give the impression that you are expecting the "for" to iterate both variables. A "for" loop only iterates a single variable. If you intend that j be assigned a vector in that statement, I recommend not indenting it to be aligned right under the "k =" of the line above.