Dr. Damien's Development - LabVIEW 2009 Data Value Reference

[DFGray]

My favorite new feature in LabVIEW 2009 is the Data Value Reference.  This is essentially a safe pointer.  It allows you to easily create locked, singleton objects with a minimum of effort.  It is also very fast.

You can find the Data Value Reference in the Application Control»Memory Control palette.  It is composed of two primitives: New Data Value Reference and Delete Data Value Reference.  Create the reference using New Data Value Reference.  Access data in it using the In Place Element Structure.  When finished, use Delete Data Value Reference to close it.  Delete Data Value Reference has an output of the current data.  This is in place with the original data (as much as possible, considering what you may do to it).

Attached is a benchmark comparing the new Data Value Reference with action engines and single-element queues to access a single element of a 1MByte U8 array buried in a cluster.  On my machine, the Data Value Reference is roughly twice as fast as the single-element queue, which is roughly twice as fast as the action engine.

What is your favorite new feature?

[RavensFan]

I just viewed that webcast today and saw this new feature.  Very interesting.

This looks like it is going to completely revolutionize the way people will program LabVIEW with large datasets.  Am I wrong?  Will new versions of articles like this need to be written?

Managing Large Data Sets in LabVIEW

[DFGray]

The semantics of the data value reference are virtually identical to the use of a single-element queue.  It is, however, much easier and safer to use, not to mention faster.  So I don't think it will completely revolutionize how people use large datasets in LabVIEW, but it will make it a lot more intuitive, so fewer people will get it wrong. Hopefully, it will also reduce the use of the global ;).

Managing Large Data Sets in LabVIEW does need to be updated.  It also does not include the In Place Element Structure, which was equally important for handling huge data sets.  It has been on my hit list for awhile, but always seems to get pushed back. Thanks for the reminder!

[Andrey_Dmitriev]

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DFGray wrote:

What is your favorite new feature?

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There are lot new features in LV2009. Right now its too early to say - which one is favorite, for example "code - snippets" are really not so bad:

Try to Drag and Drop the following picture on the BD:

 

Andrey.

Message Edited by Andrey Dmitriev on 08-04-2009 12:47 PM

[IanW]

New features in LV2009 – I haven’t loaded it yet, but this thread has just alerted me to the ‘In Place Element Structure’ from LV8.5. It does seem to have been well hidden in the Pallet structure, I wish I had known about this 18 months ago!! I wonder what I’ll be discovering about LV2009 in two years time?

 

The forum posts do a great job in highlighting many of the new features, and there are many developer zone articles scattered around the web site, but it does seem to be a very inefficient way of documenting all of the improvements. Will we ever return to the days of a proper software manual (I think version 6 was the last one) even in PDF form? - I shouldn't think so.

Ian

Message Edited by IanW on 08-10-2009 08:49 AM

[Ben]

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IanW wrote:

New features in LV2009 – I haven’t loaded it yet, but this thread has just alerted me to the ‘In Place Element Structure’ from LV8.5. It does seem to have been well hidden in the Pallet structure, I wish I had known about this 18 months ago!! I wonder what I’ll be discovering about LV2009 in two years time?

 

The forum posts do a great job in highlighting many of the new features, and there are many developer zone articles scattered around the web site, but it does seem to be a very inefficient way of documenting all of the improvements. Will we ever return to the days of a proper software manual (I think version 6 was the last one) even in PDF form? - I shouldn't think so.

Ian

Message Edited by IanW on 08-10-2009 08:49 AM

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Unfortunatly the forums are still the best place to look.

Paraphrasing

"I am tired of hearing all of these users talking about reading the bill manual. how can you expect us to read the bill manual in two days without two lawyers CLAs to explain it."

I for one would read the "Update Notes for Old-Timers" that covered EVERY change.

Ben

[F._Schubert]

Nicely said, Ben.

But I belong to the rare species that really reads and studys manuals. I remember the old days of LV 5.x where I could tell others: read the manual and do the tutorials and then you will be able to lear LV in 3 days (please note that there is a difference between LV and programming, not to mention software engineering).

But maybe that's because I need to write manuals (that no one ever reads but that are listed in the specs).

Felix

[IanW]

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Ben wrote:

I am tired of hearing all of these users talking about reading the bill manual.

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Don't wory Ben, another couple of years and we'll all be retired.

[tadders]

Has anyone else tried Data Value References with LVOOP?

I've managed to get a Data Value Reference to my base class but can't find a way to access the child class methods/attributes of the reference.

Regards

P

[tadders]

Please ignore last stupid post - I've worked it out:

Use the In Place Element Structure, add Data Value Reference Read/Write Element, cast to child object using To More Specific Class

P