LabVIEW
Subtracting an elemet from an aray
Do you just want to operate on two elements or go over the entire array recursively?
Do you just want to calculate the derivative?
Where does the time come in (i.e. your use of "most recent"). Is the array continuously being appended?
Where does the data come from?
What should happen with the result of the difference? (just display it, build another array, etc.)
What is the datatype? (e.g. be careful with unsigned integers if the result would be negative).
Once you show us your code, we can give a specific answer. before that there are way too many possible scenario/solution pairs.
Easiest would be to keep the last element in a shift register (or feedback node) and compare current to previous. No array needed.
Your description is too ambiguous and confusing. Why can't you attach a simplified version of your code??
If the array constantly appends new elements, element 0 and 1 will never change after the first two steps unless you prepend the new data to the array, which is incredibly inefficient and not recommended.
So the array only has two elements? You can use index array to get the elements at index 0 and 1, then subtract them.
If the array ever only has two elements, you don't really need an array.
This is all very basic stuff. Have you tried any of the learning resource listed at the top of the forum?
The array has 100 elements. I have tried using index array but when I used it, it only gave me 0 for the second element.
I have tried these two
You really need to stop showing us useless truncated pictures with ambiguous wiring (we can't even see where the two blue constants are connected!!! )
Attach your VI or nobody will help you. I am out!
