LabVIEW
While loop
Solved!
What is a "variable"? LabVIEW does not distiguish between row and column arrays. They are both 1D arrays. A matrix is a special datatype. Typically we deal with 2D arrays instead.
If you want to form a 2D array, you should make sure that all calls to the while loop result in the same number of column elements (maybe a FOR loop would be better?). LabVIEW does not directly support ragged arrays (you could use an array of clusters of a 1D array, for example.
Please show us your code so we get s better idea of what you are asking.
@Mark87 wrote:
I'm sorry they are numbers not variables. Yes, I want to obtain a 2d array. I start with 1d array and when I press the button stop of the while loop I want to save the numbers of the 1d array into the first column of the 2d array. Then, I will change the numbers into the 1d array and when I press again the button stop of the while loop I would like to save the numbers of the 1D array into second column of the 2D array.I can't post my code because there isn't any code at the moment.
Well,
Try something- even if its wrong!
Whatever you do, we will have that "whatever" too help us understand not only what you want to accomplish but, your LabVIEW skills and some of your thought processes. 
You might be surprised at what those clues can do to "help us help you."
It does need a lot of improvement. I'd recomend that you run your VI with highlight execution on so you can see how it is behaving now.
I'll talk about the various sections.
1. The case structure with the formula node. What is the purpose of the formula node? Also, there is no need for the case structure, it will always be True because the only way you can get to it is when you hit the Stop button to end the while loop. And when the formula node runs, it just outputs the value 1. You essentially have created a Rube Goldberg that you can just replace with a constant of 1.
2. The while loop. All it does is run as fast as possible waiting for you to hit the stop button. (Put a wait statement in there so it doesn't hog all of your CPU resources.) But the only thing the while loop does is essentially go into a polling state giving the user time to change things in the array control. The stop button is more of a "Go ON" button.
3. When your finally hit the stop button, the code finally does something. It inserts the 2nd 2-D array between columns 0 and 1 of the 1st 2-D array. Is that what you want it to do? Once it does that, your code will then stop. There is no 2nd stop or later. Your code is done and the only thing you can do is restart your VI which takes you right back to the beginning.
I have a feeling you haven't done any tutorials yet or figured out the concept of dataflow.
I would recommend looking at the online LabVIEW tutorials
LabVIEW Introduction Course - Three Hours
LabVIEW Introduction Course - Six Hours
You need a master while loop that keeps the code running until your are truly ready to stop. You may want to replace that polling while loop with an event structure that waits for you to press a boolean control called "Insert" or something like that. You should only have 1 array control. (Probably a 1-D array rather than a 2-D). Use Build array to place the 1-D array to the end of the the 2-D array that you maintain in a shift register so that the newly updated array is available for the next iteration of the while loop.
first of all this my first post on this site so please pardon me if i posted in the wrong section . i have a similar problem . i'm trying to compare between the energy pulses of two signals , one is recorded and the other is obtained using the built in microphone and use the comparison of them to either ride a case structure or follow the old cases( if else condition ) , the problem i'm facing is the program will work in the highlight excution but once i try to simulate it it will crash because of the timing issue , i'm using the 09 student version , any help will be appreciated
