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Data Copies Q#2


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So, now that AQ has convinced me I'm going to have 3 copies of my data on any open and running vi no matter what I do, here's Q#2:

This should look familiar to those of you following the first discussion. It creates 3 copies of the data:

post-9165-125430600788_thumb.png

But when I add a reference to the code as in here:

post-9165-125430606783_thumb.png

It creates four copies of the data.

This is what really started me down the road of trying to figure this out. I was seeing 4 copies of the data in my (much larger) application. So I started deleting little parts of it, saving, exiting, and running to see when the number of copies would drop. The last thing to go (other than the read file and send to graph part) was a reference to the graph that was changing the label. Once I deleted that and ran it, the number of copies dropped to 3. As it turns out, you don't have to connect the reference to anything -- just dropping it on the BD and letting it hang there also creates that fourth data copy.

Should I expect this??

I know that if I use the Value property of the array a new copy may be made (I say "may" because if you connect the read file to a Value property of the array instead of the array terminal, the # of copies stays at 3). But should I expect a copy of the data to be made just by using some non-Value property of the array?

Cat

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Can you try both examples with Syncronous display? I would guess that the reference forces the transfer copy and we have another copy still unknown.

Having "Synchronous display" checked or unchecked makes no difference to the number of data copies made. Unfortunately...

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Suggestion from LV Architect: How about an XControl whose data type is a Data Value Reference of your array and you manage the display of the data that way...

AQ fills in details:

So basically, you read your data from disk, and then use the New Data Value Reference to stuff the data into the DVR. Then you write that to the FPTerminal of a custom XControl. That custom XControl has an array display with the array index hidden. Instead, you have a separate numeric control. You grab subsets of the array to display and change which subset you get each time the user changes the value in the numeric control. This should get you down to just 1 copy of the entire array with copies of some very small subset (however big you make the display on the FP of that XControl).

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Suggestion from LV Architect: How about an XControl whose data type is a Data Value Reference of your array and you manage the display of the data that way...

AQ fills in details:

So basically, you read your data from disk, and then use the New Data Value Reference to stuff the data into the DVR. Then you write that to the FPTerminal of a custom XControl. That custom XControl has an array display with the array index hidden. Instead, you have a separate numeric control. You grab subsets of the array to display and change which subset you get each time the user changes the value in the numeric control. This should get you down to just 1 copy of the entire array with copies of some very small subset (however big you make the display on the FP of that XControl).

Unfortunately I have close to 2000 vis I have to retest everytime I upgrade. If they don't all still work it may mean a million dollar test coming to a screeching halt. Or even worse, it may mean I have to ride a submarine again. ohmy.gif So The Big Boss is very hesitant to allow upgrading. I snuck 8.6.1 in by saying it was really just a minor mod to 8.2.....

I know nothing about DVRs (other than what little I've gleaned from LAVA), but I will take a look at them on the system I have upgraded to LV9. I'll need to output the data to a graph, so displaying a little bit at a time isn't really an option -- will this method still help cut down on data copies in that case?

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I would be breaking things left and right. wink.gif "What!? I have to go out again?"

That's what I thought, too. Then I had to do it. Over and over.

If you like hot, noisy, smelly, confined, crowded spaces, it's definitely the place to be. Oh and if you don't mind being trapped in a tin can a few hundred feet deep in the ocean with no hope of survival if anything goes wrong.

I've managed to avoid riding for over a year but my number may be up this spring. I have a new system that's going on board for the first time and I (unfortunately) feel obligated to go with it and make sure it's working right on the actual test platform.

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That's what I thought, too. Then I had to do it. Over and over.

Sounds like travelling to China. Once you've done it half a dozen times you'd rather just stay home. How long are you usually out for?

I (unfortunately) feel obligated to go with it...

Meh... feelings are overrated. ;)

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How long are you usually out for?

Usually 5 days. The longest was a week. A really looong week. Electric Boat was running our system but didn't want us to touch it unless something went wrong. It was working fine so I had absolutely nothing to do and nowhere to go for a week. Oh, and that was also the trip where, due to oddities in the way federal employees get paid, I didn't get paid for the last two days.

The fun part was that it was a "Builder's Trial", the big test before the shipyard turns the boat over to the Navy, and only the second time the sub had been out to sea. On a Builder's Trial they take the boat out and "see what she can do." So we did lots of fast dives, hard turns, etc. It was kinda fun (I was watching stuff fly around the Crew's Mess at one point), as long as I didn't let myself think about what would happen if Something Important broke.

Meh... feelings are overrated. wink.gif

I'll bring that point up to my boss.smile.gif

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Or even worse, it may mean I have to ride a submarine again. ohmy.gif

Right after I decided the military was what I wanted to do the Navy was my first choice. I did extremely well in my placement tests and the Navy went out of their way trying to get me into nuclear electronics. I sat down with the recruiter and he started asking a bunch of questions.

Then the inevitable: "Are you claustrophobic?".

ohmy.gif "YES".

"Talk to the Air Force recruiter across the hall." sad.gif

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headache coming up...

so if I understand right, if I would load an image-saved-as-pixels from file, put it in an intensity graph control and have some property nodes on the diagram to set the labels of the axes..... I get /4/ data copies??

If so, is switching to a picture control beneficial?

/d

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