Array lengths and loops.

Hi,

I have a while loop set up to add a new number to the end of two arrays (postsk and weight) with every cycle of the loop. The loop runs fine, but when I then try to plot them vs. each other, I find out that the arrays are different lengths. Any idea why this is happening? Is there a limit to the number of bits in each loop? Could I be running out of memory in one loop?

The following is my code (I have removed the maths equations carried out in the while loop as I doubt those are the reason and make the code a bit easier to read).

      while (bst < 63)

        (this is where the ommited equations live, but essentially just figure out values for the upcoming if loop).

      if (resskin >= 1 & resstif >= 1 & reseuler >= 1 & resmat >= 1)

                      postsk(i) = tsk;
                      weight(i) = (((((tsk/1000)*(bsk/1000))+((tst/1000)*(bst/1000)))*(length/1000))*1600);
                      i = i + 1;
      end

      bst = bst + 1

    end

Any help would be great! Thank you!

Answer 1

[Star Strider]

The only possibility I can think of that might be causing the unequal vectors problem (not knowing more about your code) is that you previously used weight or postsk as an array, and those arrays are larger than they are assigned in the loop you posted. One cure for that might be to assign:

weight = []; 
postsk = [];

before your while loop. (I assume you don't use either variable in your while loop other than in your if block.)

[F P]

That worked! Thanks a million. Saved the day yet again :)

[Star Strider]

My pleasure!

[Matt Fig]

Good call, Star Strider. The mystery hiding in 'the unposted code' cracked by you!

[Star Strider]

Thanks, Matt. I didn't realize you were answering at the same time until after I submitted my answer.

Answer 2

[Matt Fig]

Couple of things. It looks like you are masking both the LENGTH function and the I function with a variable. Don't do that - choose a different variable name. Second, is it possible that sometimes those mysterious variables could be returning a vector or an empty? Is one of them a cell array?

Before your call to plot, put this:

whos postsk weight

and show the output.

[F P]

I should not be getting any empties or a vector, but I will try to fix the masking issue.

I also put in whos plotsk weight and got the following:

Name        Size                 Bytes  Class     Attributes

postsk      1x123102            984816  double              
weight      1x90778             726224  double

Thanks for your help and time!