Extraction of a portion from graph

[@nk]

I have to extract a portion from Graph .

I know the starting and ending point in x-axis and i have to know the y-axis values.

I have used "extract a portion of signal " express VI  but am not getting the values correctly. 

There is a picture with this, in which the portion in red box is the part i have to extract.

[udka]

Please check if this helps
https://forums.ni.com/t5/Example-Code/Extract-Data-From-Portion-of-Graph/ta-p/3494631

[@nk]

Hi uday,

Thank you for the help .

But in this VI we uses cursor to extract a part from graph. I have to extract the parts automatically.

I have got the start and end points of X-axis with me now I have to extract the part i tried with "Extract a part from signal " express vi but it is not giving a proper extraction.

Thank you

@nk

[udka]

i am not sure of express vi, can you post the vi and screenshot? with expected extraction and what you got?
-Did you try the vi in the above mentioned link?

[@nk]

Hi uday ,

Thank you for a fast response .

The VI in the above link shows how to extract a portion of graph with use of cursors. In my VI the user won't do anything . Everything should happen automatically.

First of all.

1.I have detected the peaks in my graph using a peak detector VI. This process have given me the position of peaks in terms of time (i.e x-axis units).

2. I have added a constant offset time like 0.005 sec to each time value and then I provided that value as the starting point of extraction .

3.The length till which the extraction should be done is also kept constant.

4. I just need the amplitude vales of that particular part so that I can use them for my further calculations.

For clear information I am adding  a picture of my graph in which the areas I have to extract is perfectly marked inside red box.

[.aCe. · Accepted solution]

Use get waveform subset

[altenbach]

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@nk wrote:

For clear information I am adding  a picture of my graph in which the areas I have to extract is perfectly marked inside red box.

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That picture does not help, because we don't know wat the datatype of your graph is (or even what kid of graph it is). Is it a waveform graph or an xy graph? What is the datatype if the data (dynamic, array, waveform, etc.).

The procedure will depend on the datatype and graph type.

Show us your actual VI with some typical data.