VI of the Day (9/2/2009)

[Darin.K]

No pretty pictures today, but a useful VI for graphing functions is "Eval y=f(x).vi"  It is great for creating your own graphing calculator VI, and there are several useful (and a few not-so-useful) VIs which take advantage of formula strings.  The advantage over something like a formula node is that you can change the formula at run time.  A small performance hit over hard-wired formulas, but usually well worth it in the right application.

Speaking of Formula Nodes, one of my biggest pet peeves with LV is that the exponentiation operator we know and love is really the 'Bit XOR' operator.  Not only is this different than any other language I have used (including early LV), how often are you using a Bit XOR anyway?  Now I am used to it so I had better learn to love 'y=x**2'

 

Error? What, it's not even the same in other parts of LV?!!  Arghh..... 

As always, groundrules for VIOTD here. 

Message Edited by Darin.K on 09-02-2009 09:50 AM

Message Edited by Darin.K on 09-02-2009 09:52 AM

[altenbach]

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Darin.K wrote:

Speaking of Formula Nodes, one of my biggest pet peeves with LV is that the exponentiation operator we know and love is really the 'Bit XOR' operator.  Not only is this different than any other language I have used (including early LV), how often are you using a Bit XOR anyway?  Now I am used to it so I had better learn to love 'y=x**2'

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As a reference, here's a list of differences and limitations of the formula parser VIs.

[Cory_K]

I always try to avoid formula nodes, script nodes, ect, just because then I have to remember text programming syntax.

Sometimes its unavoidable, but I try to use LabVIEW natives if possible

But I agree, this function is very useful.

Message Edited by Cory K on 09-02-2009 01:24 PM

[elset191]

I always start off in formula nodes and mathscript because it's a lot cleaner than LabVIEW for complex equations and things.  Then I translate to LabVIEW because in my experience mathscript is mega slow

[DFGray]

<historyMode>

The ** exponetial operator dates from FORTRAN.  C messed things up by using a different one.

</historyMode>

[Ben]

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DFGray wrote:

<historyMode>

The ** exponetial operator dates from FORTRAN.  C messed things up by using a different one.

</historyMode>

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<historyMode>

I have a book on a shelf in my library "FORTRAN-77". The "77" was for 1977.

So open Q to the community:

Where you a

Twinkle

• in the eye of your parents 

or

Tween

•  Alive but still young to program

or

Tweaker

• Writting your own toggle-ins  

When that book was published? 

I was a Tweaker with about 3 months experience back then.

An old joke that has probably lost its meaning since then when hardware and software type only interacted by pointing at each other goes;

"Never trust a programmer that carries a pocket screw-driver!"

</historyMode>

Ben

[Ray.R]

Good old Fortran...

I don't miss it.  

It's funny reading Darin's threads.  When I was first learning LabVIEW, I was experimenting with all the different functions, most of which I have forgotten over the years.  These threads remind me of that.  And it's a bit of a refresher..  😉

[DFGray]

TWEEN - graduated high school and on my way to a Biology major and a career as a surgeon.  I did not start programming until four years later after I changed majors to Physics.  I learned FORTRAN IV (the predecessor to FORTRAN 77) for data acquisition and analysis of nuclear isotope spectra.

[elset191]

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Ben wrote:

I have a book on a shelf in my library "FORTRAN-77". The "77" was for 1977.

Ben

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I was 10 years down the road. 

I did do some programming in Fortran-90 about 5 years ago though

[LV_Pro]

Ha! I have a copy of my Fortran IV book from college (it wasn't the 1904 version!, it was back when Fortran, like previous LabVIEW, used version numbers rather than release year). A lot of various "things" have percolated through software from the early days. Many of the keyboard shortcuts, like ctrl C, ctrl V, etc., seem to have come from one of the first word processing programs WordStar, vintage late '70s, although there may have been earlier uses.

As an aside, I have been spending some time with a LabJackU3, an instrument that a current project uses has one of these DAQ units embedded within it, and was amused by a comment in the text file included with the LabVIEW library "At its core, LabVIEW is just a graphical representation of C or similar".