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"""
================
Using TimeSeries
================
This example is intended to demonstrate the current state of `~sunpy.timeseries.TimeSeries`.
"""
import datetime
from collections import OrderedDict
import matplotlib.pyplot as plt
import numpy as np
from pandas import DataFrame
import astropy.units as u
from astropy.time import Time, TimeDelta
import sunpy.data.sample
import sunpy.timeseries
from sunpy.net import Fido
from sunpy.net import attrs as a
from sunpy.time import TimeRange, parse_time
from sunpy.util.metadata import MetaDict
##############################################################################
# We can create a range of supported timeseries:
# There is a ``source`` keyword that allows one to specify the source of the data
# It should be auto-detected in most cases.
ts_eve = sunpy.timeseries.TimeSeries(sunpy.data.sample.EVE_TIMESERIES, source='EVE')
ts_goes = sunpy.timeseries.TimeSeries(sunpy.data.sample.GOES_XRS_TIMESERIES, source='XRS')
ts_lyra = sunpy.timeseries.TimeSeries(sunpy.data.sample.LYRA_LEVEL3_TIMESERIES, source='LYRA')
ts_norh = sunpy.timeseries.TimeSeries(sunpy.data.sample.NORH_TIMESERIES, source='NoRH')
ts_rhessi = sunpy.timeseries.TimeSeries(sunpy.data.sample.RHESSI_TIMESERIES, source='RHESSI')
ts_gbm = sunpy.timeseries.TimeSeries(sunpy.data.sample.GBM_TIMESERIES, source='GBMSummary')
##############################################################################
# You can create a list of timeseries when using multiple files.
# First, we shall download these files using `~sunpy.net.Fido`.
goes = Fido.search(a.Time("2012/06/01", "2012/06/04"), a.Instrument.xrs)
goes_files = Fido.fetch(goes)
# Using these new files you get a list of timeseries
list_of_goes_ts = sunpy.timeseries.TimeSeries(goes_files, source='XRS')
##############################################################################
# You can concatenate them together using `~sunpy.timeseries.GenericTimeSeries.concatenate`
# or when creating the `~sunpy.timeseries.TimeSeries`
combined_goes_ts = sunpy.timeseries.TimeSeries(goes_files, source='XRS', concatenate=True)
# Manually
combined_goes_ts = list_of_goes_ts[0].concatenate(list_of_goes_ts[1])
fig, ax = plt.subplots()
combined_goes_ts.plot(axes=ax)
plt.show()
##############################################################################
# The TimeSeries object has 3 primary components:
#
# ``.data`` : The internal data representation. If you want the underlying data,
# use `~sunpy.timeseries.GenericTimeSeries.to_dataframe()`
# ``.meta`` : Stores the metadata that is able to be parsed from the data files
# ``.units`` : Stores the units for each column, with keys that match the name of each column.
# This will give you a useful dataframe to manipulate the data with.
lyra_data = ts_lyra.to_dataframe()
lyra_data
##############################################################################
# This will give you the metadata
ts_lyra.meta
##############################################################################
# This will give you the units
ts_lyra.units
##############################################################################
# There are a couple of other useful properties:
# The time range of the data, the name of the data columns
ts_lyra.time_range, ts_lyra.columns
##############################################################################
# Further data is available from within the metadata, you can filter out for a
# key using the :meth:`.TimeSeriesMetaData.get` method.
combined_goes_ts.meta.get("publisher_name")
##############################################################################
# You can access a specific value within the `~sunpy.timeseries.TimeSeries` data
# using all the normal `pandas` methods.
# For example, to get the row with the index of "2015-01-01 00:02:00.008000"
# Pandas will actually parse a string to a datetime automatically if it can:
lyra_data.loc['2011-06-07 00:02:00.010']
# If this fails, you will need to use parse_time to convert the string to a datetime
lyra_data.loc[parse_time('2011-06-07 00:02:00.010').datetime]
# Pandas includes methods to find the indexes of the max/min values in a dataframe:
ts_lyra.to_dataframe()['CHANNEL1'].idxmax(), ts_lyra.to_dataframe()['CHANNEL1'].idxmin()
##############################################################################
# An individual column can be extracted
ts_eve.extract('CMLon')
##############################################################################
# Changing the units for a column simply requires changing the value
ts_eve.units['a'] = u.m
##############################################################################
# Quantities can be extracted from a column using :meth:`sunpy.timeseries.GenericTimeSeries.quantity`
colname = 'CMLat'
quantity = ts_eve.quantity(colname)
quantity
##############################################################################
# You can add or overwrite a column using :meth:`sunpy.timeseries.GenericTimeSeries.add_column`.
# This method only accepts an `~astropy.units.Quantity` and will convert to the intended units
# if necessary.
new_quantity = quantity.value * 0.01 * ts_eve.units[colname]
new_eve_ts = ts_eve.add_column(colname, new_quantity, overwrite=True)
##############################################################################
# You can truncate using the :meth:`sunpy.timeseries.GenericTimeSeries.truncate` method.
ts_goes_trunc = ts_goes.truncate(0, 100000, 2)
# Or using a `TimeRange`
ts_goes_trunc = ts_goes.truncate(TimeRange('2011-06-07 05:00', '2011-06-07 06:30'))
# Or using strings
ts_goes_trunc = ts_goes.truncate('2011-06-07 05:00', '2011-06-07 06:30')
fig, ax = plt.subplots()
ts_goes_trunc.plot(axes=ax)
plt.show()
##############################################################################
# For now you can only resample by using `pandas`.
# Changing values within the dataframe directly will often affect the units
# involved, but these won't be picked up by `~sunpy.timeseries.TimeSeries`.
# Take care when doing this to ensure dimensional consistency.
df_downsampled = ts_goes_trunc.to_dataframe().resample('10T').mean()
ts_downsampled = sunpy.timeseries.TimeSeries(df_downsampled,
ts_goes_trunc.meta,
ts_goes_trunc.units)
fig, ax = plt.subplots()
ts_downsampled.plot(axes=ax)
plt.show()
##############################################################################
# The data from the `~sunpy.timeseries.TimeSeries` can be retrieved in a number of formats
# pandas DataFrame
ts_goes.to_dataframe()
# astropy Table
ts_goes.to_table()
# numpy array
ts_goes.to_array()
##############################################################################
# Creating a `~sunpy.timeseries.TimeSeries` from scratch can be done several ways.
# Input data can be in the form of a `pandas.DataFrame` (preferred),
# an `astropy.table.Table` or a `numpy.array`.
base = datetime.datetime.today()
dates = Time(base) - TimeDelta(np.arange(24 * 60)*u.minute)
intensity = np.sin(np.arange(0, 12 * np.pi, ((12 * np.pi) / (24 * 60))))
# Create the data DataFrame, header MetaDict and units OrderedDict
data = DataFrame(intensity, index=dates, columns=['intensity'])
meta = MetaDict({'key': 'value'})
units = OrderedDict([('intensity', u.W / u.m**2)])
# Create the TimeSeries
ts_custom = sunpy.timeseries.TimeSeries(data, meta, units)
fig, ax = plt.subplots()
ts_custom.plot(axes=ax)
plt.show()
|
