# When is a timeseries a time series?

Working on Challenge 2:
Variable “hdata” is timeseries, but not!?

Here is code:

``````# Challenge 2 (2 points) -- Rookie
# Signal in colored, Gaussian noise.

# Use the data file "challenge2.gwf", with channel name "H1:CHALLENGE2"
# The data contain a BBH signal with m1=m2=30 solar masses, spin = 0.

import gwpy
from gwpy.timeseries import TimeSeries
import numpy
import pylab
%matplotlib inline

print(f"time series = {hdata}")
print( "\n***************************")
print(f"datatype for variable hdata = {type(hdata)}")
print( "***************************")

print(f"          delta_t = {hdata.dt}")
print(f"number of samples = {len(hdata)}")
print(f"     elapsed time = {hdata.dt*(len(hdata)-2)}")
print(f"    sampling rate = {1/hdata.dt}")
hdata.plot()
import pylab
from pycbc.catalog import Merger
from pycbc.filter import resample_to_delta_t, highpass
##################################################
# Preconditioning the Data
###################################################
strain = highpass(hdata, 15.0)
``````

Here is stuff that worked:

``````time series = [ 1.16850460e-22 -6.44996982e-22 -3.20366127e-22 ...
-1.91886478e-23 -2.10989354e-22  2.30287965e-22] ct

***************************
datatype for variable hdata = <class 'gwpy.timeseries.timeseries.TimeSeries'>
***************************
delta_t = 0.000244140625 s
number of samples = 262144
elapsed time = 63.99951171875 s
sampling rate = 4096.0 1 / s
``````

Here is failure info:

``````---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
Input In , in <cell line: 30>()
26 from pycbc.filter import resample_to_delta_t, highpass
27 ##################################################
28 # Preconditioning the Data
29 ###################################################
---> 30 strain = highpass(hdata, 15.0)

File ~/.local/lib/python3.9/site-packages/pycbc/filter/resample.py:302, in highpass(timeseries, frequency, filter_order, attenuation)
272 """Return a new timeseries that is highpassed.
273
274 Return a new time series that is highpassed above the `frequency`.
(...)
298
299 """
301 if not isinstance(timeseries, TimeSeries):
--> 302     raise TypeError("Can only resample time series")
304 if timeseries.kind is not 'real':
305     raise TypeError("Time series must be real")

TypeError: Can only resample time series
``````

Any help is appreciated.

forgot “Timeseries.” wish I could delete this post

@buyukcam Hi! It looks like you read in the data using `gwpy`, but then tried to use a high pass filter from `pycbc`.

`gwpy` and `pycbc` both have an object they call `timeseries`, but they are not the same object! In general, you’ll want to pick one package at a time to use. Or, to say it a different way, if you read in the data with `gwpy`, then you should also use `gwpy` to process and plot the data.

Good luck!

Thanks, Jonah! I’m going through the tutorials again in a more organized manner.
Thanks again!! (great relief)