From Friday, April 19th (11:00 PM CDT) through Saturday, April 20th (2:00 PM CDT), 2024, ni.com will undergo system upgrades that may result in temporary service interruption.

We appreciate your patience as we improve our online experience.

LabVIEW

cancel
Showing results for 
Search instead for 
Did you mean: 

rising slope array

Solved!
Go to solution

Hi,

 

I am trying to find a solution for splitting arrays. I have data from a graph going into an array. It has 360 measurements. X is Degrees and Y is Force. Since its like a positive sine waveform pattern on the graph, I want to create some sort of rise and fall detection so that each positive sine waveform gets seperated into a new array until it detects a negative slope and so on for the next ones. I could use slope function to detect a positive slope but I dont know how I could use it together with split, index and build array.

 

Any ideas?

0 Kudos
Message 1 of 6
(3,127 Views)

Hi rvkamat,

 

I have data from a graph going into an array.

Wrong wording. You have data going from an array into a graph…

 

I want to create some sort of rise and fall detection

Calculate derivative?

 

how I could use it together with split, index and build array.

Then you should try to "split, index and build array" with a test VI. Once you know how to "split, index and build" arrays you can combine this with your "slope" VI…

Best regards,
GerdW


using LV2016/2019/2021 on Win10/11+cRIO, TestStand2016/2019
Message 2 of 6
(3,116 Views)
Solution
Accepted by topic author rvkamat

Taking the derivative will give you the slope.  From there, you can easily find the indecies for when the slope changed directions.  Then use Array Subset with those indecies to make up your new arrays.


GCentral
There are only two ways to tell somebody thanks: Kudos and Marked Solutions
Unofficial Forum Rules and Guidelines
"Not that we are sufficient in ourselves to claim anything as coming from us, but our sufficiency is from God" - 2 Corinthians 3:5
Message 3 of 6
(3,077 Views)

Thanks. Its a little bit complicated than that since I dont know if there is a positive slope or negative slope in the beginning or it could even start from the peak.

 

So I need to check a slope with the derivative function (I implemented it), then stop when there is a negative slope so that I get a Positive Sine Waveform (works) , take the array subset from the index I find (I am having trouble with Arrays but I will figure it out)...I need to do this 6 to 7 times

0 Kudos
Message 4 of 6
(3,058 Views)

If you get stuck, post what you have so far and tells us what you don't understand.  We are usually pretty good at giving nudges in the right direction.


GCentral
There are only two ways to tell somebody thanks: Kudos and Marked Solutions
Unofficial Forum Rules and Guidelines
"Not that we are sufficient in ourselves to claim anything as coming from us, but our sufficiency is from God" - 2 Corinthians 3:5
Message 5 of 6
(3,036 Views)

Thanks crossrulz. Smiley Happy

0 Kudos
Message 6 of 6
(3,009 Views)