Advanced formula parsing and arrays

[Snamprogetti]

I'd like to eval formulas with an array input, such as

y = x[i] + x[j] .....

This can be done normally with a Formula Node when the formula is static, but how about when the formula itself is an unknown string? None of the Advanced Formula Parsing VIs seems to fit.

[chilly_charly]

Your question is too general. You should give an example of what you want to accomplish.

[AlessioD]

The question is way too generic to ba able to create a specific example.
I believe you could look at the example that is found in the following folder

labview\examples\math\math.llb\Behavior of Modified Function Graph.vi

which uses the formula parsing from string function.

Regards,

AlessioD

[Snamprogetti]

INPUTS:

• a C-like formula with an array argument of unknown size, y = f( x[ ] )
• an array of doubles of unknown size, x[ ]

OUTPUT:

• the result of the formula, y

EXAMPLE:

Input Formula (sums the elements of an array):

y=0;
int i;
for (i=0; i<N; i++)
    y += x[i];

Input Array (size N=3):

x = { 3, 4, 5 }

Output:

y = 12

[chilly_charly]

I don't think Formula vis (such as the  Parse Formula String vi) accept loop operators, although the formula node does.

In LV 8.0, you can use a MathScript Node, which uses a syntax similar to MathLab.