How to know data value of a certain point on graph/charth/plot??

[abtj1990]

I have attached snapshot of front panel and block diagram of my vi

I am interested in two calculations: settlingMin and settlingMax

Althought i get other parameter values from time response parametric data including settling time as shown on front panel but i am not able to find settlingMin and settlingMax

I have also attached snapshot defining what settlingMin and settlingMax are in thoery

[Bob_Schor]

If you looked at a few entries on this forum, you would have picked up a request (I always mention it when appropriate) that the Original Poster post code (meaning "attach one or more VIs") rather than pictures of code (which are hard for us to edit, execute, sometimes even see, as the print can be miniscule).

Please attach your VI, preferably with some data we can use to test your algorithm and our suggestions to how you might proceed.  Speaking for myself, I'd like to suggest things for you to try, rather than "do your homework for you"...

Bob Schor

[abtj1990]

please check attached vi

[altenbach]

You must have custom mathscript code and some toolkits (control design, etc.), because your VI is not runnable on my system.

Maybe all you need is attach your VI containing default data in the graph?

Your data is relatively simple. Do you just need the values quantized to the actual points or more precise? Is the data always right-side up? Does it always start at zero? Is this always a simulation or can there be noise for the real case?

RiseTime: use "threshold array" with a value based on e.g. a fraction of max(array)

Peak: use "array Min&Max" for SettlingMax and PeakTime

Settling max: use "array Min&Max" for SettlingMin position of subset after max.

Settling time: Look at how it is defined. Looks like the point immediately after the last point that is outside the special region.

Of course more ideally you would program the mathematical model and do a nonlinear fit based on the above initial values.

Once you have these positions, you can place graph annotations or highlight them in some other way.

[abtj1990]

How can i apply your advised following configuration:

"

Rise time: use "threshold array" with a value based on e.g. a fraction of max(array)

Peak: use "array Min&Max" for max position and value

Settling max: use "array Min&Max" for min position of subset after max.

Settling time: Look at how it is defined. Looks like the after the last point that is outside the special region." 

[altenbach]

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@abtj1990 wrote:

How can i apply your advised following configuration:

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I would use LabVIEW, of course.

Do you have any specific question? As I already said, we can give more specific advice once we have a VI with typical data. (I cannot run your VI to generate data myself).

[Yamaeda]

You can add a Cursor to the Graph, link it to a channel and ask/extract the value of some index. I probably not the best solution, but it's a fun one. 🙂

/Y

[Ben]

Did not read all of the previous but...

Mouse Down event can be used with Invoke Node Get plot as well as the Map XY to...

THe first methods tells us which plot to look at and the second tells us where to look in the indicated plot's data set.

Have fun!

Ben

[altenbach]

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@Ben wrote:

Mouse Down event can be used with Invoke Node Get plot as well as the Map XY to...

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The question has nothing to do with user interaction, but to find characteristic turning points in a given dataset, then indicate them on the graph.