From re.rezaei at gmail.com Mon Dec 2 12:40:27 2019 From: re.rezaei at gmail.com (Reza Rezaei) Date: Mon, 2 Dec 2019 15:10:27 +0330 Subject: [obspy-users] Variables in header Message-ID: Hello every one, In SAC, we can write couple of variables in the header (T0~T10). Is there any similar approach to write and retrieve variables in Stream or Trace? Best regards, Reza -------------- next part -------------- An HTML attachment was scrubbed... URL: From megies at geophysik.uni-muenchen.de Tue Dec 3 14:17:43 2019 From: megies at geophysik.uni-muenchen.de (Tobias Megies) Date: Tue, 3 Dec 2019 14:17:43 +0100 Subject: [obspy-users] PPSD workflow In-Reply-To: <1616240347.49079.1574741556391@mail.yahoo.com> References: <1616240347.49079.1574741556391.ref@mail.yahoo.com> <1616240347.49079.1574741556391@mail.yahoo.com> Message-ID: Hi Januka, the approach very closely follows the processing workflows described in the references papers / technical reports by McNamara et al. http://docs.obspy.org/citations.html?highlight=mcnamara By default PPSD works on 1-hour slices (like PQLX), but that can be changed. For details please see the source code: https://github.com/obspy/obspy/blob/4c83dfc6e4a6ae4c93c8681349661d67d48505bc/obspy/signal/spectral_estimation.py#L903-L1001 As you can see in there the psd is reused from matplotlib: https://matplotlib.org/3.1.1/api/mlab_api.html#matplotlib.mlab.psd cheers, T On 26/11/2019 05:12, Januka Attanayake wrote: > Hi,? > Does the PPSD class follow the same workflow as that described in the > PQLX manual? i.e., is the day long file truncated to the next lowest > power of two?? > > "First, to significantly improve the Fast Fourier Transform (FFT) speed > ratio, by reducing the number of operations, the number of samples in > the time series, N, is truncated to the next lowest power of two, 217, > leaving N=131,072, thereby reducing the series length such that > Th=3276.8s. Second, in order to further reduce the variance of the final > PSD estimates, each roughly 1-hour time series record is divided into 13 > segments, overlapping by 75 percent, where the length of each new time > series segment is now, Tr=Th/4=819.2s with N=32,768=215." > > Thanks! > > Januka > From megies at geophysik.uni-muenchen.de Tue Dec 3 14:28:38 2019 From: megies at geophysik.uni-muenchen.de (Tobias Megies) Date: Tue, 3 Dec 2019 14:28:38 +0100 Subject: [obspy-users] ObsPy at AGU 2019 Message-ID: Hi all, I'll be at AGU and there will be a lightning talk in an Open Source software session (NS21A) on Tuesday morning: https://agu.confex.com/agu/fm19/meetingapp.cgi/Paper/577013 Also following this oral session there are a few posters from this session (NS21B) so we'll be gathering there and you can get in touch with me there on Tuesday around 10am to noon: https://agu.confex.com/agu/fm19/meetingapp.cgi/Session/78079 We'll also organize an informal gathering for food/drinks in the evening on one day. It's not yet fixed when, but it'll be posted on our Twitter and (hopefully I'll remember) also here. https://twitter.com/obspy Also you can send a direct message on Twitter if you wanna get in touch during AGU. cheers, Tobias From jkmacc at lanl.gov Tue Dec 3 16:10:43 2019 From: jkmacc at lanl.gov (MacCarthy, Jonathan K) Date: Tue, 3 Dec 2019 15:10:43 +0000 Subject: [obspy-users] Variables in header In-Reply-To: References: Message-ID: Hi Reza, Trace objects have a .meta attribute that is essentially just a dictionary, and can hold any keys and values you add to it. Just be careful not to overwrite the core keys, like ?starttime?, ?sampling_rate?, etc. Best, Jon ------------------------------------------------------------------------------------ Jonathan K. MacCarthy Seismoacoustics Team Los Alamos National Laboratory Phone: 505-665-4448 Cell: 505-695-5044 ------------------------------------------------------------------------------------ On Dec 2, 2019, at 4:40 AM, Reza Rezaei > wrote: Hello every one, In SAC, we can write couple of variables in the header (T0~T10). Is there any similar approach to write and retrieve variables in Stream or Trace? Best regards, Reza _______________________________________________ obspy-users mailing list obspy-users at lists.swapbytes.de https://lists.swapbytes.de/mailman/listinfo/obspy-users -------------- next part -------------- An HTML attachment was scrubbed... URL: From jattanayake at yahoo.com Wed Dec 4 09:17:51 2019 From: jattanayake at yahoo.com (Januka Attanayake) Date: Wed, 4 Dec 2019 08:17:51 +0000 (UTC) Subject: [obspy-users] PPSD workflow In-Reply-To: References: <1616240347.49079.1574741556391.ref@mail.yahoo.com> <1616240347.49079.1574741556391@mail.yahoo.com> Message-ID: <551085015.3127481.1575447471030@mail.yahoo.com> Thanks as always Tobias! Januka Attanayake Research Fellow | Earthquake Seismology Homepage:?https://sites.google.com/site/janukaattanayake School of Earth Sciences | McCoy Bldg. 200 University of Melbourne | Parkville 3010 VIC Australia On Wednesday, 4 December 2019, 2:05:51 am AEDT, Tobias Megies wrote: Hi Januka, the approach very closely follows the processing workflows described in the references papers / technical reports by McNamara et al. http://docs.obspy.org/citations.html?highlight=mcnamara By default PPSD works on 1-hour slices (like PQLX), but that can be changed. For details please see the source code: https://github.com/obspy/obspy/blob/4c83dfc6e4a6ae4c93c8681349661d67d48505bc/obspy/signal/spectral_estimation.py#L903-L1001 As you can see in there the psd is reused from matplotlib: https://matplotlib.org/3.1.1/api/mlab_api.html#matplotlib.mlab.psd cheers, T On 26/11/2019 05:12, Januka Attanayake wrote: > Hi,? > Does the PPSD class follow the same workflow as that described in the > PQLX manual? i.e., is the day long file truncated to the next lowest > power of two?? > > "First, to significantly improve the Fast Fourier Transform (FFT) speed > ratio, by reducing the number of operations, the number of samples in > the time series, N, is truncated to the next lowest power of two, 217, > leaving N=131,072, thereby reducing the series length such that > Th=3276.8s. Second, in order to further reduce the variance of the final > PSD estimates, each roughly 1-hour time series record is divided into 13 > segments, overlapping by 75 percent, where the length of each new time > series segment is now, Tr=Th/4=819.2s with N=32,768=215." > > Thanks! > > Januka > _______________________________________________ obspy-users mailing list obspy-users at lists.swapbytes.de https://lists.swapbytes.de/mailman/listinfo/obspy-users -------------- next part -------------- An HTML attachment was scrubbed... URL: