from string to block diagram

[KF_]

Hi,

I need to know how you can translate a string, a formula, to the block diagram. So for instance, if you have G=5+3*lnW, how can you translate the ln to the ln in the block diagram. The formula isn't fixed so I can't make a hard code.

Thanks in advance

KF_ 

[billko]

edit: oops didn't see that the formula always changes

[KF_]

The goal is that I can give in the formula in the front panel, not in the block diagram like the formula node

[josborne]

Check this out, my friend:

http://zone.ni.com/reference/en-XX/help/371361G-01/gmath/advanced_formula_vis/

[billko]

That's great - I just learned something new!

[Mark_Yedinak]

You would need to write a parser that would evaluate the equation entered. If you use RPN this is fairly easy to do. RPN is nice since it lends itself well to using a stack for processing the equation and you will always be dealing no more than the top two elements of the stack. Your evaluation routine would be in a loop that would parse the equation and invoke the proper case in a simple state machine. You will need to use a shift register to store the variables, operations and intermediate results as you parse the equation. You would need a case for each operation you will support.

[KF_]

Ok, these comments should help me enough, cheers

[jcarmody]

Is Python an option?  Look at this example I posted (a few years ago - wow) using LabPython.