Gary Rubin

QUOTE(Dan Bookwalter @ Dec 28 2007, 03:12 PM)

well on windows you can hold down the ALT key then using the keypad enter the ascii code for the character you want , if remember correctly the degree is ALT-167 ....

You can also used the Windows character map to find the symbol (it's in the Symbols font), copy it to the clipboard, then paste it into LabVIEW.

QUOTE(Falevoz Y. @ Dec 28 2007, 12:29 PM)

Ok, understand.

It could be great for my curent project. Would you give an example VI?

http://lavag.org/old_files/monthly_12_2007/post-4344-1198863394.gif' target="_blank">

The library calls are to kernel32.dll. The function names are the labels of the library calls.

Labview will remain in high priority as long as it is open. I have not tried this with built executables, but presume it should work the same.

Microsoft's MSDN webpage will give you the values for normal and above-normal priority.

QUOTE(Falevoz Y. @ Dec 28 2007, 07:56 AM)

What is the difference with the priority in the VI property?

The VI priority refers to the priority of the thread within Labview in which that VI is executed. The Windows priority refers to the priority within the Windows tasks with which Labview is executed.

One word of caution - if your CPU usage is pegged at 100% and you've set Labview to high priority, your ability to move/minimize windows can be limited.

QUOTE(AdamRofer @ Dec 26 2007, 07:45 PM)

1) Force the application priority AboveNormal/High/RealTime using win32 dll calls (http://msdn2.microsoft.com/en-us/library/ms686219%28VS.85%29.aspx' target="_blank">setPriorityClass) or a third-party app that can enforce application priority based on the program (like "Iarsn's TaskInfo"). This affects a single process quite a bit for performance.

We've had good luck with this.

QUOTE(Kevin P @ Dec 21 2007, 10:49 AM)

I'm interested in memory / performance tradeoffs of waveforms vs. arrays as well. I learned NI data acq before the waveform datatype was invented. When it came out, it looked to me like an overture to new users who might have trouble handling the relationship between sample rate and elapsed time. As with many other "innovations" that seemed to be aimed at new users, I've treated the critters with an abiding suspicion.

I agree 100%. I never really adopted waveforms because, when they came out, I thought of everything other than the data array as "overhead" that I didn't really need or want.

Gary

QUOTE(Gustavo Fernandes @ Dec 19 2007, 01:25 PM)

It works well in the small project but not in the big one, looks like labview take a large amount of time processing mathscipt before running, or something else I'm missing. Also the code has many variables and parameters. I would prefer to do it keeping the matlab code I wrote before and integrating it in labview (dll, activex, etc).

I don't know if this still holds true for Labview 8x, but in Labview 7.1, there's something called a Matlab Script (under the Analyze > mathematics> formula) tools palette.

This is different from Mathscript. Mathscript, as I understand it, has Labview compiling and executing M code (or at least a subset of it). The Matlab Script launches an instance of matlab, much as I would assume you're trying to do with activex.

QUOTE(Gustavo Fernandes @ Dec 18 2007, 08:10 AM)

I am new to using external code. I'm trying to use some matlab code inside labview (without using mathscript).

Does the Matlab Script structure still exist in LV8.20? Why not use this?

Did this snapshot preview thing go away sometime in the past couple weeks, or is it just me?

Gary

QUOTE(neB @ Oct 18 2007, 10:29 AM)

I'm not sure what a split infinitive is.

I should have said "To what does this refer", not "What does this refer to".

QUOTE(neB @ Oct 18 2007, 10:29 AM)

Ah, I see. So that means that 5M individual users have requested tech support since that system was started?

QUOTE(neB @ Oct 18 2007, 10:14 AM)

My freshest rookie has an NI contact ID# just short of 5M.

Ben,

Just about every part of that statement is over my head. What does that refer to?

(yeah, yeah, split infinitive - my wife is the English major, not me...)

Gary

QUOTE(eaolson @ Oct 18 2007, 12:35 AM)

I can't agree more. I imagine one of the big fish in the programming game is Visual Studio, which pretty much maxes out with the Professional version for $670, a factor of 2 cheaper than LabVIEW's starting version. The Standard version is $250. Some LabVIEW versions are an order of magnitude more expensive than that.

I think you may be comparing apples and oranges a bit here.

I don't have much experience with those other languages, but I would consider LabVIEW to be a higher-level language than C, etc.

If you look at the function palette, I see the stuff in the red box as pretty much your "basic" programming capability. The other stuff, especially the Analyze section, is what you're getting for your extra $k.

http://lavag.org/old_files/monthly_10_2007/post-4344-1192713314.gif' target="_blank">

A better comparison might be to other high-level technical languages, such as Matlab or IDL. With those languages, as with LabVIEW, you are paying for more than just a compiler and a basic command set; you are also paying for 1) a considerable library of specialized functions that you don't have to write yourself, and 2) the fact that you don't have to define all your variables and can add a float to an integer and get the right answer.

Now, maybe 1) is the point of the request for LabVIEW light? If someone doesn't need to do all that mathematical stuff, it would be nice to choose to not pay for that part.

Incidentally, I was in a Matlab training class yesterday. One of the introduction slides claimed that Matlab is used by more than 1E6 users in over 130 countries.

I don't know LabVIEW's numbers, but I would suspect that they are smaller. As a comparison point, a single-user Matlab license is $1900. I think the difference is that Matlab is in schools.

Sorry for this meandering message. I use LabVIEW as a general purpose language for performing "technical computing", and I guess that's where the identity crisis comes in: When we're talking about making LV more mainstream, are we talking about more mainstream within the programming world, or more mainstream within the technical computing world?

Gary

QUOTE(PJM_labview @ Sep 20 2007, 02:28 PM)

While I would not necessary expect improved performance, I certainly would not expect worse one. But this has happened.

Hmmm, that does seem odd - maybe a difference in memory speed between the single-core and dual-core systems?

QUOTE(PJM_labview @ Sep 20 2007, 11:54 AM)

So in some situation, you may have some code that may use briefly 90% of a single core processor and take about 1s to run and the same code on the multi core will be balanced at about 50% on each core and take 2s to run.

This sounds indicative of non-parallel dataflow. What you described sounds like each core is spending half its time waiting for the other to finish.

If you do not see total CPU usage over 50%, then you are not actually doing anything in parallel and would not expect any better performance than a single core.

QUOTE(eaolson @ Sep 19 2007, 05:41 PM)

Can I expect to just drop any old VI on a multicore computer and see a significant increase in speed, or would it have to be carefully optimized for multicore execution?

I think the answer is "yes" to both. It depends on how parallel your processing is. You usually can see some increase in performance just by dropping it onto a multicore system, but you might be able to do much better by being careful with your threading and taking advantage of some of the thread priority settings.

QUOTE(crelf @ Sep 18 2007, 10:52 PM)

Is it http://www.calbay.com/bxi_index.html' target="_blank">BXI compatable?

You too can be the proud owner of a $15k beer tap! :laugh:

Does anyone have any experience with EasyDaq hardware?

Thanks,

Gary

QUOTE(Michael_Aivaliotis @ Sep 9 2007, 07:48 PM)

There are some minor glitches but all will be fixed over time.

Michael,

Thanks for the work on the site, as always.

Here's one of the glitches: View New Posts just brings me to a search window.

Thanks,

Gary

QUOTE(Val Brown @ Sep 7 2007, 08:18 PM)

The system can also call additional components, some third party, and what happens that is curious is that cpu load and balance is DRAMATICALLY impacted by simpy left clicking and holding down that click on one of the window frames. Let me say this another way. While the program is running I can decrease cpu load by "grabbing" the window frame of (any of) the components, as if I wanted to move that window around on the desktop. While the "mouse down" event is happening -- but not in terms of any specific control(!) -- cpu load drops, sometimes quite dramatically.

I have seen something that sounds similar to this on WinXP and LV7.1.

I have some pretty CPU-intensive processing going on, pulling data from a file, with large preallocated arrays feeding 2D intensity plots that are updated every N iterations of the processing loop. What I found was that if I clicked and held on the "window minimize" button in the upper right corner of the front panel, it appeared that the processing would be sped up dramatically. I assumed that clicking and holding on that minimize button forced Windows to maintain focus on the processes associated with the window, therefore speeding things up.

My processing loop was set to run as fast as possible. If yours is waiting on external events, then we might be seeing similar things. Yours is manifested by the processes finishing faster and therefore spending more time waiting, while mine was manifested as faster execution time.

Does that sound reasonable?

I don't know about Vista, but I've recently been playing with Windows priorities in WinXP. You might try that and see what happens?

QUOTE(Ben @ Aug 31 2007, 10:47 AM)

I The letters "A" and "V" are also troublesome.

That's interesting; I had been aware of the word jumbling, but not the orientation issues. It's really fascinating how the brain works. My http://en.wikipedia.org/wiki/Sue_Rubin' target="_blank">sister is severely autistic, and it's really amazing to see what aspects of her brain seem to function normally vs. which parts don't...

Gary

QUOTE(Ben @ Aug 31 2007, 09:29 AM)

The other theory was (but addressed by teh poll buy mentioned by others) that there is a higher proportion of engineers and scientists that are dyslexic than in the general population.

If you read the wikipedia entry on handedness, there are some interesting theories about how handedness is related to language development. Maybe that goes along with the dyslexia thing? I don't know enough about dyslexia or neurology to know if dyslexia and language are related...

QUOTE(Aristos Queue @ Aug 28 2007, 09:29 PM)

If you accidentally hit ctrl+t and tile your windows, you can use ctrl+z to undo that change. It won't undo the block diagram, but your carefully sized front panel window will be restored. Not everyone notices that sizing the panel is an undoable operation, so I thought I'd mention that.

Good to know. Thanks!

QUOTE(george seifert @ Aug 28 2007, 10:45 AM)

You guys are hijacking my thread. Could we please get back to the original question?

Sorry...

QUOTE(Ben @ Aug 28 2007, 10:26 AM)

That is part of the reason I preceed the crtl-e with a ctrl-s.

Which leads to another question/pet peeve... Why does LabVIEW clear the undo buffer when a VI is saved? Just because I saved something doesn't mean I don't want to go back to what I had before the save.

QUOTE(Ben @ Aug 28 2007, 09:44 AM)

"ctrl-t" ?

I hate ctrl-t. I especially hate that it's next to the ctrl-R, so it inadvertently gets hit sometimes and I have to resize my windows again.

While I'm ranting about my fat-fingering, I wish ctrl-E and ctrl-W weren't next to each other...