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Ambrose,
I'm puzzled. You appear to be taking a class in LabVIEW, as this sounds like an interesting Homework Assignment, yet you seem to know almost nothing about LabVIEW, the common Structures (While Loops, For Loops, etc.), how arrays behave, the principles of Data Flow, and other topics that should have been covered in the first few classes.
Have you spent any time with the Tutorial material listed on the upper right corner of the LabVIEW Forum's first page? You can also do a Web search for LabVIEW Tutorials -- a number are videos.
To help you get started, I'm attaching Project Palindrome, a LabVIEW Project (which you probably don't know about) that contains three VIs -- Find Palindromes (which directly returns an array of all the Palindrome integers up to some "Top" Integer), a sub-VI, Is Palindrome, which tests an Integer and returns a Boolean (True if it is an Palindrome), and another sub-VI, Reverse Digits, that returns the reversed-digit version of its input integer.
These are exactly the VIs I suggested to you in my reply yesterday. One of my colleagues showed you something similar to my Find Palindromes, but included a "Starting Integer" (whereas I implicitly start at 0).
Some things to note about this Project and the VIs inside:
- You open a Project by clicking on the .lvproj (the "Project") file, here called "PROJECT Palindrome.lvproj". When it opens, it will show you all of the VIs included in the Project, and will simplify linking them together into a cohesive whole. I recommend creating a Project File for all but the most trivial "stand-alone" VIs.
- Find Palindromes is "finished" in the sense that there is nothing more to do with this VI. Let me show it to you:
Note the sub-VI "Is Palindrome" -- you "know" what it is because it has an icon that identifies it. So you can look at this top-level VI and say, "Yes, if "Is Palindrome" works as advertised, this will produce an array of all of the Palindromes from 0 (the starting value of the For Loop) to (oops, actually) one less than the value I have in "Top" Integer. [How embarrassing -- an off-by-one error!]. Do you understand the function of the Indexing Tunnel on the output of the For Loop? Do you understand the Conditional part of this tunnel?
- When I run this, it finds 1098 Palindromes from 0 to 100000 (actually, because of the off-by-one bug, 0 to 99999), and does it in about 20 milliseconds.
- I've included "dummy" versions of Is Palindrome and Reverse Digits. The VIs have Icons (so you can easily identify them on the Block Diagram), inputs, and outputs, but there is no code on the Block Diagram -- that's left for you to fill in.
- These VIs illustrate some good practices you should follow if you want to do any serious LabVIEW programming, in particular, if you want to write some LabVIEW code that you will likely use for an extended period of time (i.e. more than just the next Class Assignment). They include the following:
- VIs are mostly written to do Just One Thing, but to do it well, and completely.
- Every VI has an Icon that makes it "obvious" what it does (makes the Block Diagram that uses the VI easier to understand).
- Every VI uses the 4-2-2-4 connector pane, which makes the Inputs and Outputs line up nicely.
- Every sub-VI has an Error In and Error Out cluster wired to the lower left and right connectors.
- Every VI had a Description that (briefly) says what it does and names its Inputs and Outputs.
I realize that this is probably "overkill", given your level of expertise, but I'm hoping that maybe you'll take an interest and apply yourself to learning LabVIEW by doing some work, yourself, instead of coming to us and asking us to do it for you. And if not, maybe another student who might follow this thread will learn something useful ...
Bob Schor
P.S. -- oops, almost posted without the attachment ...
