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Good Math, Bad Math


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I've just starting learning about Matlab, and while surfing found this blog that I now subscribe to.

I liked this entry called Why so many languages? Programming languages, Computation, and Math

The entry does not mention LabVIEW directly, but this post by Bob Munck made me smile:

Back in the late 70's, NRL hired my company (SofTech) to figure out why software for its AN/UYS-1 signal processing computer was so expensive and so bad. I was technical director of the DC office and project lead. We discovered that the acoustical engineers specified the software by drawing data flow diagrams where the nodes were mostly a standard set of operations like "FFT," "Bandpass Filter," etc. Those diagrams would be given to a roomfull of programmers who would laborously convert them into sequential SPL/1 or CMS-2 code by essentially ripping the functionality apart and re-assembling it in a "crystal clock architecture."

My big idea seems pretty obvious now, but was radical then: create an engine that will run the dataflow diagrams. We wrote a parser to convert the diagrams into an internal form and an interpreter to run it on the UYS-1. Worked like a charm; we took a diagram that (ahem) IBM had spent several tens of millions of 1970's dollars converting into code and got it running in about a month with five programmers. Believe it or don't, our implementation was slightly faster. Long story short, the Navy specified that the next generation of signal processors, the AN/UYS-2, be designed (by Bell Labs) as a dataflow engine at the hardware level. That machine and that architecture are still in use today.

So that's an example where a highly-specialized programming language was the right solution, if you're willing to call dataflow diagrams a programming language. Note, though, that we eliminated the programmers.

Calling dataflow diagrams a programming langauge? A highly-specialized programming language consisting of an engine that runs dataflow diagrams that perform FFTs and bandpass filtering? Where have I heard of this before? Oh yeah.... :lightbulb:

(Where can I find the NI blue eagle logo in the smilies list?)

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Might it predate NI's patents on the basic LabVIEW system? ...

Well, curious as I am, I Googled "Bob Munck Softech" I found where Bob made references to "SADT: Structured Analysis and Design Technique".

You can read more about SADT in a PDF file at the top of this page. I haven't got the time to read it thoroughly, but the date was 1977 and contained some interesting hand-made drawings...

What's weird is that I also found a Softech Alumni page that includes the name of an ADA programmer who works for my company, and he's just recently started learning LabVIEW!

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Well, curious as I am, I Googled "Bob Munck Softech" I found where Bob made references to "SADT: Structured Analysis and Design Technique".

You can read more about SADT in a PDF file at the top of this page. I haven't got the time to read it thoroughly, but the date was 1977 and contained some interesting hand-made drawings...

What's weird is that I also found a Softech Alumni page that includes the name of an ADA programmer who works for my company, and he's just recently started learning LabVIEW!

Looks like a VI hierarchy to me :-)

post-17-1152287018.png?width=400

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And this hierarchy is one of the key claims in the original LabVIEW patents (over 10 years later...). So much for the "prior art" portion of patent office due diligence.

I've read a lot of the NI patents[*] with respect to LabVIEW and I don't remember the heirachy being in them. Just about everything else is there including the underlying structure of a VI, dataspaces, icons, connector panes, VI flow diagrams, etc, but not VI heirachy diagrams. That said, it's more than possible that I may have missed that page of that particular patent...

[*] ok, so I'm a geek - but you'd be amazed with what you can learn about LabVIEW's underlying engine by checking them out - I highly recommend it for those who prefer to understand the engine before complaining about it :) . When you've got a lunch hour to spare and a good cup of tea, here's some of the more interesting ones to check out - I suggest you start form the bottom and go straight to the images section. Of course, some of the patents are more inspired than others :D

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