How can I get an array of points where each point is a cluster of x and y coordinates from a waveform?

[菁菁]

Dear all

Now I use the VI of  "Threshold 1D Array", I input "array of numbers or points"  a waveform,and want to get the x value of this waveform from "fractional index or x".

In the detail help, I know that if I want to get the x value from   "fractional index or x", I should give an array of points where each point is a cluster of x and y coordinates. so How can I get an array of points where each point is a cluster of x and y coordinates from a waveform?

Thank you for any help!

Jing

[菁菁]

maybe this one is much more clear

[smercurio_fc]

This is continuation of this thread. Please keep the discussion to the original thread so others can follow it. You're not really asking anything new.

As you saw from the Help, that function accepts an array of numbers, so why are you trying to pass a cluster? You have the X and Y arrays right there that you're bundling!


To learn more about LabVIEW it is recommended that you go through the tutorial(s) and look over the material in the NI Developer Zone's Learning Center which provides links to other materials and other tutorials. You can also take the online courses for free.



Message Edited by smercurio_fc on 04-29-2008 02:26 PM

[菁菁]

Dear all,

I want to get the exact X value in the FOR LOOP.

Now I have two ideas:

1st, It looks like in the attached file, but after the Threshold 1D array, I only can get the fractional X index, then the index go to the index array. As the data type of the index array is Signed Integers, so I can not get the exact X value.

2nd, from the detailed help of Threshold 1D array, I know If the array input consists of an array of points where each point is a cluster of x and y coordinates, the output is the interpolated x value corresponding to the interpolated position of threshold y among the y coordinates, rather than the fractional index of the array.

But I really don't know how to get the array input consists of an array of points where each point is a cluster of x and y coordinates.

If somebody knows something, please tell me.

Thank you for any help

Jing

[smercurio_fc]

Use the Interpolate 1D Array function.

Your code, simplified to use autoindexing:



Also, an example using the array of clusters that the Help is talking about:




Message Edited by smercurio_fc on 05-05-2008 11:23 AM

[菁菁]

Dear Smercurio

I am so apprieciating for your help! Thank you very much!

Jing