Creating lookup table

[shashank]

Dear people,

I want to make up a lokup table for a sigmoid waveform, to which i can enter the x values and the output i get is the y value which i can give as an input to a transfer function. can anyone please help me with this. i am new to labview and trying to implement a model, i m almost done but stuck up with this problem. if anyone can please help will be of great help.

[Aristos Queue]

QUOTE(shashank @ Sep 5 2007, 04:31 AM)

Dear people,

I want to make up a lokup table for a sigmoid waveform, to which i can enter the x values and the output i get is the y value which i can give as an input to a transfer function. can anyone please help me with this. i am new to labview and trying to implement a model, i m almost done but stuck up with this problem. if anyone can please help will be of great help.

Two options have just appeared on radar.

If you're using LV 8.2...

Go to ni.com/labs and click on the Generic Container download.

If you're using LV 8.5...

try this out: http://forums.lavag.org/Map-implemented-with-classes-for-85-t8914.html' target="_blank">http://forums.lavag.org/Map-implemented-wi...r-85-t8914.html

Otherwise, there are two options that you have historically in LV:

1) Create two parallel arrays and add and remove from both simultaneously. You can use Search 1D Array to find the value in the X array and then return the complimentary value in the Y array.

2) You can use the attributes of a Variant; flatten your X to a string and use that as the key to store attributes whose value is y. Later you can retrieve the values by looking up attributes on the variant.

[orko]

Since you are dealing with a sigmoid, if you are looking for the time of a certain data value (best fit) within a tolerance you can also use the "Search Waveform.vi" in the waveform palletes.

http://forums.lavag.org/index.php?act=attach&type=post&id=6854