Slicing the large file

Usage Questions
1

There is a continuous miniseed file of 10 days. I would like to slice it into a file of 1 day and want to save in miniseed format.

I tried the code

import glob                                 
from obspy.core.stream import read
from obspy.core import UTCDateTime

mseed_file = read("5daysfile.mseed")

stime=mseed_files[0].stats.starttime

for i in range(0,432000,86400):
    print(stime+(i),stime+(i)+86400)
    mseed_files.slice(stime+(i),stime+(i)+86400)

But it doesnot slice the data instead same data it appends.Any help is highly appreciated.Thanks.

2

No reply yet…Is it the right place to ask the question related to obspy…

3

It’s absolutely the right place. Please check out the documentation of Stream.slice():

https://docs.obspy.org/packages/autogen/obspy.core.stream.Stream.slice.html

4

Above code doesnt look too far off…

...
    tmp = mseed_files.slice(stime+(i),stime+(i)+86400)
    tmp.write(f'my_filename_{i}.mseed', format='MSEED')

You could make it a bit nicer though regarding times

start = min(tr.stats.starttime for tr in mseed_file)
end = max(tr.stats.endtime for tr in mseed_file)
year = start.year
doy = start.julday
t1 = UTCDateTime(f'{year:4d}-{doy:03d}T00:00:00')
while t1 < end:
    t2 = UTCDateTime(f'{year:4d}-{doy + 1:03d}T00:00:00')
    tmp = mseed_file.slice(t1, t2)
    tmp.write(..., format='MSEED')
    # move on
    doy += 1  # needs some more sophisticated logic if wrapping around new year, obviously
    t1 = UTCDateTime(f'{year:4d}-{doy:03d}T00:00:00')
5

@megies if possible please post the full code using my example data set.