Picking data from graph?

I have a sample signal below, I just want to retrieve the data in the red box for the next step of processing, how do I do it?

[Walter Roberson]

What information do you have about the location of the red box?

Is the original signal still available, or only the graph of the signal ?

[Nurfaiz Fathurrahman]

I don't really understand what you mean, but

x = time

y = amplitude

The signal above is just an example, the original signal is still available

let's say I have a signal in the time domain as above, in the processing that I do I will not use all the signals, so I will take the data x and y in a certain time as in the red box to do further processing

sorry for bad english

[Walter Roberson]

How should the program know where to start extracting? How should the program know where to stop extracting ?

Is the time range fixed? Have the times been input by the user? Does the program need to detect the first minima and extract everything to the sixth minima ?

[Nurfaiz Fathurrahman]

is it possible to retrieve data by picking in the graph? or use another method so that it can determine the start and end?

time range is fixed, signal is input using exsisting data

Answer 1

[Bjorn Gustavsson]

If you have the signal S, the corresponding sample-times t and the start and stop-times t1 and t2 you can select the signal in the intervall:

S1to2 = S(t1<t&t<=t2);

If you want to select the time-interval from the graph, have a look at the help and documentation of ginput, it is a function that allows you to select points in graphs. You could use that to select 2 points (you will/can get bot the x and y-values of selected points) to give you t1 and t2.

HTH

[Nurfaiz Fathurrahman]

Excellent, i tried ginput and got what i wanted, thanks a lot

Sorry late reply