if condition

[srt]

Hi, I try to creat a vi to result the folowing statement:

if 0<= x<=0.05, d=4;

 else if 0.5 <x <= 0.1 d=3.5;

    else if 0.1 <x <=0.2, d=3;

      else if 0.1 <x <= 0.2, d=2.5;

   .........

      else if 1.6 <x<=3, d=0.5;

when i use the case structure in labview, it's too many case statements.

caould you tell me some easy way?

many thanks

[chilly_charly]

case statements in LabVIEW can handle numeric inputs (polymorphism...), but this works only with integers.
A simple solution to your problem is to multiply the x value by 100, juste to create integer values, then to create the corresponding cases. Remember that a case statement accept "lists and ranges of values in the case selector label at the top of the Case structure. For lists, use commas to separate values. For numeric ranges, specify a range as 10..20, meaning all numbers from 10 to 20 inclusively. You also can use open-ended ranges. For example, ..100 represents all numbers less than or equal to 100, and 100.. represents all numbers greater than or equal to 100". The quotes delimit a chunk of the LV help.

[Sreedhar_T]

Hi,

The best way is to use the "Formula Node" and write the complete C code in it.

[chilly_charly]

---

TSreedhar a écrit:

Hi,

The best way is to use the "Formula Node" and write the complete C code in it.

---

Well, I don't think that a lot of people here will consider this as the best solution ! 😉 Remember that most of us are "C impaired" people :D. That's just why we use labVIEW : to forget about textual code !

[Ray.R]

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srt wrote:

if 0<= x<=0.05, d=4;

 else if 0.5 <x <= 0.1 d=3.5;

    else if 0.1 <x <=0.2, d=3;

      else if 0.1 <x <= 0.2, d=2.5;

   .........

      else if 1.6 <x<=3, d=0.5;

<=3, d="0.5;

This is just an example, right?

You are not trying to assign a value to d = 3 or 2.5 based on 0.1<x<=0.2 

If the above formula is true, then what value gets assigned if x is between 0.11 to 0.2?

I would implement the approach suggested by CC.  

Ray

[Ben]

And yet another "G-reat" approach uses the in-range and search 1-d array to give you the ability to

change ranges and "D" values at run-time by replacing the constants with controls.

X is compared with each of the ranges specified by the costants.

The resulting boolean array is searched for the first "true" and the index tells which "D" value to select.

Ben

[Sreedhar_T]

I think this solution is really good. Its worse to complicate things by multiplying with 100 and mess around with the code. That was really nice Ben.

[chilly_charly]

Even simpler...

Message Edité par chilly charly le 10-19-2005 04:01 PM

[fati]

svp aidez

c'est urgent

je veus réaliser un filtre passe bas en labview de f(p)=wn²/wn²+2xip+p²
pour xi<0.7
xi=0.7
0.7i<xi
voila mon e-mail:fat_na@hotmail.com

[Sreedhar_T]

Hey this speaks of a cool solution too... thanks a lot.