Formula Node Error

[Chhavi]

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

[GerdW]

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…

[wiebe@CARYA]

A for loop around the expression node would work too.

Indeed, no reason for the FN...

[alexderjuengere]

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

[billko]

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.)  😄

[wiebe@CARYA]

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:

y=x*12,34;

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

[alexderjuengere]

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: 

http://zone.ni.com/reference/en-XX/help/371361R-01/lvinstio/degrees_to_radians/