Response accelerograms cannot feature more than 200000 time

02-Analytical capabilities
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EmerssonB
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Joined: 09 Mar 2019, 15:51

Response accelerograms cannot feature more than 200000 time

Post by EmerssonB »

Hello, I've been trying to scale a 150 seconds accelerogram but this message appears "Response accelerograms cannot feature more than 200000 time-acceleration pairs of values"". Can you explain this please.
huffte
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Joined: 22 Jul 2011, 10:19
Location: Cookeville, Tennessee, USA
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Re: Response accelerograms cannot feature more than 200000 t

Post by huffte »

What is the time step for your accelerogram (it must be quite small)? Even at 0.005 seconds, the number of pairs would be 150/0.005 = 30,000. If the number of records does indeed exceed the limit, you may still be able to process the accelerogram by specifying a frequency of 2 when you load the record. This would halve the number of points read and you would need to double the time step to keep the data accurate. If further reduction is needed, you could specify a frequency of 3 and triple the time step.
Tim Huff
EmerssonB
Posts: 3
Joined: 09 Mar 2019, 15:51

Re: Response accelerograms cannot feature more than 200000 t

Post by EmerssonB »

Hi, the time step is 0.005, it is 31632 values of acceleration, but it still shows the message "Response accelerograms can not feature more than 200000 time-acceleration pairs of values" when I try to do the matching. This is the file:
https://drive.google.com/open?id=1QYkvN ... lg7CLK1_el_
This is the accelerogram:
https://drive.google.com/open?id=1RhOIK ... guq4lqAMWg
And this is the spectrum:
https://drive.google.com/open?id=1vNmwe ... LFPqmYMwtu
Can you check it please.
Thanks a lot
huffte
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Joined: 22 Jul 2011, 10:19
Location: Cookeville, Tennessee, USA
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Re: Response accelerograms cannot feature more than 200000 t

Post by huffte »

I get the same error when I open your file, EmerrsonB. To test it out, I opened a file of my own which has 30,000 points and I still get the same error message as you regarding exceeding 200,000 points. I then tried opening my file only reading 1/2 of the points (a total of 15,000 points) and still get the message. So I am not sure what is going on there, but it appears to be a bug.

Here is the interesting part. If I define the target spectrum as an EC8 code spectrum, I never get the error. Even if I load your accelerogram with 31,000 + points, the error never occurs and the matching process converges.

So a note to the SeismoSoft team, it appears that defining a target spectrum form a file is not working properly and is producing confusing error messages. The size of the input accelerogram does not appear to be the problem.
Tim Huff
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z.gronti
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Joined: 16 Oct 2013, 08:14

Re: Response accelerograms cannot feature more than 200000 t

Post by z.gronti »

Dear EmerssonB,

The reason why you receive such an error message is because the matched accelerogram that SeismoMatch tries to create exceeds the limit of 200000 time-acceleration pairs of values. Hence, I would suggest to load the original accelerogram with less time-acceleration pairs of values (this affects the number of time-acceleration pairs of values of the matched accelerogram) or increase the value of the Min. Period, i.e. the Lower period bound within which spectral matching is carried out.
Zoi Gronti
Seismosoft Srl.
Jbull
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Joined: 30 Mar 2023, 20:10

Re: Response accelerograms cannot feature more than 200000 time

Post by Jbull »

Hi,

I am having a similar issue with both 200000 time-acceleration values and with out of memory errors. I have read in other threads about timestep and frequency adjustments, but have not found success - especially when my seed file has time and acceleration values per line. In this case I am not able to adjust frequency, so the frequency-time step trick is not possible. I suppose I could import to excel and remove every other row, but this would be a tedious work around. Has anyone had good success matching long duration files (eg. Japanese subduction events) in this software?

I have also adjusted the min period for matching to get a result, however I need to increase the min period to above the target Tmin for my period range of interest.

Any advice would be appreciated.

Thanks,
huffte
Posts: 978
Joined: 22 Jul 2011, 10:19
Location: Cookeville, Tennessee, USA
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Re: Response accelerograms cannot feature more than 200000 time

Post by huffte »

I would suggest a couple of different options.

1. Load the seed accelerogram and identify ranges at the beginning and at the end which have essentially zero (or very close to zero) acceleration values. Specify a first line and a last line that eliminates these leading and trailing zeroes.

2. There is a vast abundance of high quality ground motion records from many different earthquakes available with vastly fewer time-acceleration pairs. Use a different seed record.
Tim Huff
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