Who has an example? duration of a waveform above threshold

[Danny29434]

Excuse me,

does anyone know how to find the duration? like this picture.

Please help me.
Thank you

[GerdW]

Hi Danny,

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@Danny29434 wrote:

does anyone know how to find the duration? like this picture.

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You need two steps:

1. Find the first time the signal rises above your threshold value.
2. Find the last time the signal falls below the threshold…

Subtract both times…

What have you tried?

(In the end it boils down to comparisons and search array functions.)

[santo_13]

To make things simple, square each point and then take a square root, now, the signal is single-sided, now, you can do all sorts of comparisons to find the duration above a threshold.

[Danny29434]

Hi gerdW,

Thank you for the advice
I try this but it's not work

I don't have idea about finding the first time and last time (What function should I use?)
My English's not good and I don't understand some function ---> that's my problem

Thank you Very much.

[GerdW]

Hi Danny,

like this:

(There's a small bug: you need to search for TRUE both times.)

Hint: time duration is the number of sample (aka difference of indices) multiplied by dt (aka time interval between samples)…

Recommendation: cleaning up the block diagram helps to improve readability of your code!

[Danny29434]

Hi GerdW,

I tried following your advice. But it still doesn't work. 
Maybe I misunderstood something. Can you help me check my code? (Thank you very much)
I tried this (picture 1) and the result (picture 2)

                                                                                              picture 1

                                                                                                           picture 2

index of rising is correct but the index of falling is not
then I tried this (picture 3)  and the result (picture 4)

                                                                                           picture 3

                                                                                           picture 4

index of rising is still correct (2179) but the index of falling should be 8297 (In picture 4).
about 2382 is the next index that is above the threshold
and then I tried this (picture 5) It' still doesn't work


                                                                                            picture 5

Best regards,
Danny

[JÞB]

Hint.

Threshold array x2,  array size, reverse array and subtractx2 (or a compound math.)  You don't need any of the silly comparisons. 

You'll get there.

If you search my old posts for "Trim.vim" you might find an example that I believe even has a waveform datatype case.