Expression evaluation

[Kahr]

Tried it. Option. But have You had a look at the LabVIEW code behind the vi. Oohh.

[johnsold]

And you wanted to write your own instead???

If you have a very limited set of functions (like a 4-function calculator) you might be able to create soemthing simpler, but would it be versatile enough to be useful?

Do you have a description of the possible functions, the number of variables, and the size of the formula?

Lynn

[Corny]

hehe,

Created once a "virtual tag engine" where the user could create virtual tags with math using other existing tags using thoes VI's.. well I didnt have any problems with testing a lot of these tags performance wise (but had a low update freq). However I think in "clean" LV it might be your only option?

[Kahr]

I've found implementation of sinus in the parse formula vis. But no ABS, SQRT...

[Corny]

You sure? I believe they can be used as of I can remember

[Corny]

Found the old source code in the library.

Atleast of what I saw:

Abs(), cosh, sinh, tanh, log2, acos, atan, sqrt, ln, ^, acosh, asinh, csc, cot, atanh, log, sin, cos, asin, multiply, minus, divide, add

can be used. prob more

[Kahr]

Lynn. The customer asks for trigonometric functions and SQRT, ABS etc. I've allready implemented the 4 function calculator in Labview and could add the requested additional functions but would prefere to use an allready existing and proven one.

[Kahr]

Corny. Thanks. I look deeper into it. Thanks

[Corny]

Youll find them all in the LV help: 

[jcarmody]

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@Kahr wrote:
I just noticed the dll jcarmody. Is python server running in the background ?

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I just uninstalled Python, put a copy of the dll in the VI's folder and modified the BD to find it.  It ran fine and there's no Python server running.  The documentation for the PYTHON Set Server Path VI says "This function configures the interface to use a particular Python shared library."