Wiring the 'N' terminal inside a For Loop

[Justin Goeres]

Our local users' group last night had a presentation based on the Tips and Tricks to Speed LabVIEW Development session from NIWeek. Since I missed that one at the conference, I went. On one of the slides, there was a new (to me) tip that wasn't part of the presentation.

You can use the N terminal of an auto-indexing For Loop as a proxy to the size of the (smallest) incoming array. All these years, I've been manually calculating the Array Size outside the loop!

Of course, it's obvious now that I've seen it. Am I the last person in the world to learn this?

EDIT: This was supposed to go in the LabVIEW (General) forum, but in my excitement I posted it in the wrong place.

[Chris Davis]

QUOTE(Justin Goeres @ Sep 12 2007, 08:17 AM)

Am I the last person in the world to learn this?

No, you're not the last person in the world to learn this. I am. Thanks for sharing the information, I didn't get to attend that session at NIWeek either.

[Justin Goeres]

I just realized that calling that indicator "% complete" in the example code was an absolutely braindead choice... :headbang:

[Aristos Queue]

QUOTE(Justin Goeres @ Sep 12 2007, 08:17 AM)

Of course, it's obvious now that I've seen it. Am I the last person in the world to learn this?

You may have just learned this, but it could be worse. I've actually received a product suggestion that said "LabVIEW should have a better way to calculate the size of an array". The method used in the attached VI would make your diagram look something like this:

http://lavag.org/old_files/monthly_09_2007/post-5877-1189607671.png' target="_blank">

So you're doing fine.... ;-)

[Grampa_of_Oliva_n_Eden]

QUOTE(Justin Goeres @ Sep 12 2007, 09:17 AM)

...

Of course, it's obvious now that I've seen it. Am I the last person in the world to learn this?

...

I reacted the same way when I saw someone wire an enum to a format into string. I thought it was great but everyone else said "You didn't know that?"

I think this is not our short-coming but rather due to the sparse upgrade notes. I religeously read every one of these cover to cover and still I miss stuff.

WE really need EXHAUSTIVE upgrade notes!

Ben

[Aristos Queue]

QUOTE(Ben @ Sep 12 2007, 09:40 AM)

WE really need EXHAUSTIVE upgrade notes!

I don't think that would've helped for your enum example nor Justin's wire-the-N. Those have been in LabVIEW for a long long time.

[crelf]

QUOTE(Aristos Queue @ Sep 13 2007, 12:32 AM)

I've actually received a product suggestion that said "LabVIEW should have a better way to calculate the size of an array".

There's a better way?

[ragglefrock]

QUOTE(crelf @ Sep 12 2007, 10:06 AM)

There's a better way?

I prefer this method of getting an array's size.

[David Boyd]

QUOTE(ragglefrock @ Sep 12 2007, 11:23 AM)

I prefer this method of getting an array's size.

Oooh, now that's so "clever" it's downright scary. I would have NEVER thunka' that as an alternative.

Dave

[jaegen]

QUOTE(crelf @ Sep 12 2007, 08:06 AM)

There's a better way?

I think AQ's "friend" didn't realize there was an "Array Size" function built into LV, and was calculating them him/herself with the method shown.

Jaegen

[crelf]

QUOTE(jaegen @ Sep 13 2007, 02:13 AM)

I think AQ's "friend" didn't realize there was an "Array Size" function built into LV, and was calculating them him/herself with the method shown.

I was kidding

[Grampa_of_Oliva_n_Eden]

QUOTE(jaegen @ Sep 12 2007, 12:13 PM)

I think AQ's "friend" didn't realize there was an "Array Size" function built into LV, and was calculating them him/herself with the method shown.

Jaegen

It could be worse! The customer could have sumbitted the following code to find array size.

http://lavag.org/old_files/monthly_09_2007/post-29-1189618192.png' target="_blank">

Yep, it rediculous.

Yes, I wrote it.

Ben

[crelf]

QUOTE(Ben @ Sep 13 2007, 03:30 AM)

It could be worse! The customer could have sumbitted the following code to find array size.

What the? Can you talk us through it?

[Ton Plomp]

QUOTE(crelf @ Sep 12 2007, 07:43 PM)

What the? Can you talk us through it?

Well that's what the http://forums.ni.com/ni/board/message?board.id=170&message.id=267659&page=1&view=by_date_ascending' target="_blank">NI forums is for in dept problem generation instead of solving

Ton

[lavezza]

This all reminds me of some code a hardware vendor supplied us many years ago. I've reproduced the style below. Creative(?!) use of the N terminal.

[Thang Nguyen]

QUOTE(Ben @ Sep 12 2007, 09:40 AM)

I reacted the same way when I saw someone wire an enum to a format into string.

@Ben: Could you tell me what is the format into string VI? I don't know about this . I have to you the property strings[] and array indicator to get the string of an enum.

@All: You guys are experts in LabVIEW, so if you have time, it's really helpful if you can list down these tricks in VI. I really want to learn more about these stuffs. It's hot :thumbup: .

Thang Nguyen

[Justin Goeres]

QUOTE(crelf @ Sep 12 2007, 08:06 AM)

There's a better way?

This gives me an idea for kind of a cool thing to do. Not a Coding Challenge exactly, but more like a Cleverness Festival! :beer:

We could pick an interesting trivial problem (Array Size is a really good one) and challenge LAVA members to find original (not optimal) ways to solve it. We could constrain it with a few simple rules like

• Must not use any subVIs except those provided in vi.lib or OpenG.
  
• All code must fit in a block diagram window of a certain size (and no stacked sequences!)
  
• All code must obey basic LabVIEW style conventions
  

or whatever. I'm just brainstorming here. Might be fun to see what's lurking in the corners of our brains.

[crelf]

QUOTE(lavezza @ Sep 13 2007, 04:28 AM)

This all reminds me of some code a hardware vendor supplied us many years ago. I've reproduced the style below.

I feel dirty (and not in a good way).

QUOTE(Justin Goeres @ Sep 13 2007, 04:40 AM)

a

Cleverness Festival!

That sounds awesome!

[Justin Goeres]

QUOTE(Thang Nguyen @ Sep 12 2007, 11:31 AM)

@Ben: Could you tell me what is the format into string VI? I don't know about this . I have to you the property strings[] and array indicator to get the string of an enum.

Welcome to The Cool Kids' Club:

http://lavag.org/old_files/monthly_09_2007/post-2992-1189622895.png' target="_blank">

Format Into String is in your String palette.

BTW, there's a more versatile Get Strings from Enum function in the OpenG Data Tools library. It takes a variant as input, so you're not limited to using it with just one enum.

[Ton Plomp]

QUOTE(Justin Goeres @ Sep 12 2007, 08:40 PM)

This gives me an idea for kind of a cool thing to do. Not a Coding Challenge exactly, but more like a Cleverness Festival! :beer:

We could pick an interesting trivial problem (Array Size is a really good one) and challenge LAVA members to find original (not optimal) ways to solve it. We could constrain it with a few simple rules like

• Must not use any subVIs except those provided in vi.lib or OpenG.
  
• All code must fit in a block diagram window of a certain size (and no stacked sequences!)
  
• All code must obey basic LabVIEW style conventions. It's an exercise in creativity, not obfuscation.
  

or whatever. I'm just brainstorming here. Might be fun to see what's lurking in the corners of our brains.

QUOTE(crelf @ Sep 12 2007, 08:42 PM)

That sounds awesome!

Well to get started (this are the easy ones)

Note: the second method only goes for brown cluster arrays or numerics (eg static length per element)

Ton

[Grampa_of_Oliva_n_Eden]

QUOTE(tcplomp @ Sep 12 2007, 03:17 PM)

Well to get started (this are the easy ones)

Ton

RE: My array size example

"If you want people to respond, say something rediculous." (Ben)

The Interesting Stuff thread that Yen started on NI has lot of links to LV trivia.

For obfuse code see the thread that Christian started. It has examples that range from the simple to the subtle.

Ben

[jpdrolet]

QUOTE(Justin Goeres @ Sep 12 2007, 02:49 PM)

Welcome to The Cool Kids' Club:

Format Into String is in your String palette.

BTW, there's a more versatile Get Strings from Enum function in the OpenG Data Tools library. It takes a variant as input, so you're not limited to using it with just one enum.

I think an even lesser known trivia is to use Scan from String to read an enum string

[eaolson]

QUOTE(Justin Goeres @ Sep 12 2007, 08:17 AM)

Of course, it's obvious now that I've seen it. Am I the last person in the world to learn this?

I believe I can authoritatively say no, you weren't the last. Now, am *I* the last person in the world to learn this?

For some reason, I knew you could wire the N terminal inside a For loop, but doing it in the case of an auto-indexed loop never occurred to me.

[lavezza]

Here's my Array Size.

[LAVA 1.0 Content]

QUOTE(eaolson @ Sep 12 2007, 04:39 PM)

I believe I can authoritatively say no, you weren't the last. Now, am *I* the last person in the world to learn this?

Sorry, it's not you, it's me! No wonder I failed the CLD on the first pass. :headbang:

Next thing is someone will tell me I can convert an enum to a string with a single function :laugh: (Yes, I know how)

I actually learned many of the enum tricks when reading "http://safari.oreilly.com/0130093653' target="_blank">A Software Engineering Approach to LabVIEW"