decimate array deletes odd element

[tst]

OK, you're right, sorry. You can give as many single stars as you like to that one.

I wasn't near a computer with LV at that moment and I did that from memory. I was sure for some reason this was so. Probably had something to do with the fact that when you create pages the following pages are empty.

Maybe it's time I take a vacation as well...

And can you get rid of that horrendous yellow?

[chilly_charly]

Ah-Ah, so you are prone to error ? Or may be the fact that you have difficulties with 3D objects means that you are from the other sex ?

To learn more about LabVIEW, I suggest you try searching this site and google for LabVIEW tutorials. Here and here are a couple you can start with. You can also contact your local NI office and join one of their courses.
In addition, I suggest you read the LabVIEW style guide and the LabVIEW user manual (Help>>Search the LabVIEW Bookshelf).

[chilly_charly]

And the color was not yellow !

It was Gold...

[tst]

Looks like you are as color blind as a frog.

[Philip_Courtois]

Okay guys - STOP FIGHTING

I aggree that the behavior of the Decimate Array function is non-intuitive when the size of the array os not an integer multipla of the number of decimated arrays. Therefore I have submitted the behavior to the LabVIEW R&D group for further investigation and hopefully improvements in the future of LabVIEW.

Thanks, Garvacious, for reporting this behavior...

[Philip_Courtois]

Okay, I just heard back from R&D that this behavior is known and expected. There is even a KnowledgeBase describing the behavior:

Why Does the Decimate 1D Array Function Drop the Last Element from Some of the Output Arrays in LabV...

However, since this behavior DOES cause some confusion, I will create a product suggestion for supporting different size decimated arrays. I will also submit a suggestion to add documentation about this behavior for the function as long as it still has the current behavior.

Thanks y'all for helping with the feedback!

[Garvacious]

Sorry for the late reply- I haven't had time for this message board for a few months.  

Phillip, I think suggesting a change to this behavior would be great.  I get the need to make both outputs the same number of elements, but any behavior that causes you to LOSE data seems like a bug to me, even if it is "known and expected".  Better to have extra zeroes to play with than lose your valuable real data in this function.

[Philip_Courtois]

Hi Garvacious,

I have submitted both a corrective action request and a product suggestion for this feature. In my product suggestion, I suggest that it becomes optional to either use the old functionality that limits all output arrays to the size of the smallest array, or to simply use different sized outputs. Here is the diagram I submitted to show the ideas for the suggested feature:



Let's see what this turns into in the future...

Message Edited by Philip C. on 10-25-2005 12:42 AM

[THailey3]

This was reported to R&D (# 3OT0Q8SG), but was determined to be expected behavior as explained in the KB linked to above by Philip.  Also, this behavior is consistent with the Interleave Array function, which stops when the smallest input array is completely consumed.  However, if you feel strongly about this, I encourage you to create a product suggestion and describe in detail why the current behavior should be different.

As for better documentation on this function...  This was reported to R&D (# 2TGDGR0Q).

I hope this helps,

[THailey3]

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@altenbach wrote:

Actually, I think that this is as expected. I you don't like the behaviour, you can simply reshape (=pad) the array to the next higher integer multiple of the desired decimation factor before decimation. 😉

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However, there is a bug in the documentation:

The online help states that the input  "...array can be a 1D array of any type, except Boolean."

This is no longer true, boolean input arrays work just fine! 🙂

(This must have been a leftover statement from LabVIEW 4.x, where boolean arrays wre stored differently)

While we're at it, the documentation should probably mention that the decimation can cause truncation if the input array is not divisible by the decimation factor.

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This was reported to R&D (# 38RG954B) and was fixed in LabVIEW 8.0. Here is a link to the current evaluation software download for LabVIEW.

Thanks!