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Formula Node Error

I am entering this formula :



z = -10*log((10**((x)/10))-(10**(-(y)/10))); in the formula node.  An error is displayed. Error on line 1 is marked by a '#' character: "... = -10*log((10**((x)#/10))-(10**(-(y)/10"    Formula node: array indexing expected. Did not get it. Please provide me with a solution





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Message 1 of 7

Hi Chhavi,


Did not get it.

So you wire an array to your formula node - and don't get the error ""array indexing expected"?


Why use a formula node at all?


Because of famous polymorphism you can easily replace the controls/indicators by arrays…

Best regards,
CLAD expired, using LV2011SP1 + LV2017 (+LV2019 sometimes) on Win7+cRIO
Kudos are welcome Smiley Wink

Message 2 of 7

A for loop around the expression node would work too.


Indeed, no reason for the FN...

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Message 3 of 7


You can process arrays in the formula node, but it's quite a hassle



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Message 4 of 7

I abhor the formula node for the simple reason that you have no chance for syntax error using native math primitives instead.  (My typing is, well... bad.)  Smiley Very Happy

(Mid-Level minion.)
My support system ensures that I don't look totally incompetent.
Proud to say that I've progressed beyond knowing just enough to be dangerous. I now know enough to know that I have no clue about anything at all.
Humble author of the CLAD Nugget.
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Message 5 of 7

I do like expression nodes for simple scaling, like going from mm to m and vice versa.


A typical bug with the formula node and expression node is related to the fact that we use commas as separators over here. And when you use a number with a comma, you can get a valid expression, but not a valid result:




This results in y=12 for x=1, not y=12,34! 


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Message 6 of 7

Moreover, you can't inline a subvi, which has an expression node or formula node within


that's the main reason we use those structures only for prototyping

here's my favorite:

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Message 7 of 7