WorkingWithFlags.py

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# # Working With TOA Flags
#
# ``PINT`` provides methods for working conveniently with TOA flags.  You can add, delete, and modify flags, and use them to select TOAs.
#

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from pint.toa import get_TOAs
import pint.config
import pint.logging

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pint.logging.setup("WARNING")

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# Get a test dataset.  This file has no flags to start with.

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t = get_TOAs(pint.config.examplefile("NGC6440E.tim"), ephem="DE440")
print(t)

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# The TOAs are stored internally as an ``astropy.Table``:

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print(t.table)

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# You can look at the flags directly (note that the leading ``-`` from a file has been stripped for internal storage).  The initial file did not have flags, so these (``format``, ``ddm``, and ``clkcorr``) were added by ``PINT`` when reading:

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print(t["flags"])

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# Which is just looking at the ``'flags'`` column in the TOA table:

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print(t.table["flags"])

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# To extract the values of a flag, you can just treat it like an array slice

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print(t["ddm"])

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# However, flags are stored as strings, so you might use a function that also allows type conversions:

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ddm, _ = t.get_flag_value("ddm", as_type=float)
print(ddm)

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# It's also easy to add flags.  In this case we will just add to the first 10 TOAs:

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t[:10, "fish"] = "carp"
print(t["flags"])

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# If we now try to get those values:

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print(t["fish"])

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# it will return the flag value or an empty string when it is not set.  On the other hand:

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fish, idx = t.get_flag_value("fish")
print(fish)
print(idx)

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# Will also return an array of indices when the flag is set.
# Now let's set some other fish:

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t[10:15, "fish"] = "bass"

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# and we can select only the TOAs that meet some criteria:

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basstoas = t[t["fish"] == "bass"]
print(len(basstoas))

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# Which can be combined with other selection criteria:

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print(t[(t["fish"] == "carp") & (t["mjd_float"] > 53679)])

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# You can set the value of a flag to an empty string, which will delete it:

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t["fish"] = ""
print(t["flags"])

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