Allow CALC_ prefix as an alias for DP_

[taldcroft]

Description

MAUDE uses the prefix CALC_ to indicate pseudo-MSIDs that are calculated from actual spacecraft MSIDs, for example CALC_ROLL_FSS. Cheta uses DP_ for the same meaning, and many calcs have the same name apart from CALC_ vs DP_. The good news is that MAUDE also accepts DP_ as a prefix.

This PR does a simple translation of CALC_ to DP_ in input MSIDs to enable interoperability. This is especially useful for a query that uses both CXC and MAUDE for the backend data source. This translation is seen in self.MSID (backend query version) but not in self.msid (user-supplied version).

Finally, the plot method was updated to use an upper-cased version of the user-supplied MSID. So if the user asks for calc_pitch_fss then they see CALC_PITCH_FSS in the plot title, while pitch_fss goes to PITCH_FSS. In both cases the internal self.MSID would be DP_PITCH_FSS since that is what is used in the backend query.

This requires https://github.com/sot/maude/pull/39

Interface impact

The interface now allows MSIDs with a prefix of CALC_.

The title in plots made from an MSID object has been changed. Previously it included self.MSID which is
the internal version used to actually fetch telemetry data. Now it is self.msid.upper(), which is an upper-cased version of the MSID specified by the user in the query. For instance if you did dat = fetch.Msid('pitch_fss', ...), previously the plot title was DP_PITCH_FSS but now it will be PITCH_FSS.

Testing

• Passes unit tests on MacOS (with new unit test)
• Functional testing

Functional testing

Made the following plots to confirm the update to the plot title.

In [2]: dat = fetch.Msid('calc_pitch_fss', CxoTime.now() - 3)
In [3]: dat.plot()
In [4]: dat.iplot()

In [5]: dat = fetch.Msid('calc_pitch_fss', CxoTime.now() - 3, stat='5min')
In [6]: dat.plot()
In [7]: dat.iplot()

In [8]: dat = fetch.Msid('calc_pitch_fss', CxoTime.now() - 30, stat='5min')
In [9]: dat.iplot()

[javierggt]

Looks simple enough to me.

[javierggt]

do you care that the MSID changes? in other words:
d1.MSID == d2.MSID is True as well.

[taldcroft]

Yes, that change in the MSID from what the user provides was annoying me. The problem is that fixing that requires handling the different prefixes at a lower level in the code. So in the end I went for "perfect is the enemy of good" here.

I think that if you provide a single MSID (i.e. not a glob) then d1.msid will reflect what you provided.

[javierggt]

I have no issues with it changing as long as one knows and perhaps documented, I just checked that it does change:

In [1]: from cheta import fetch

In [2]: dat1 = fetch.Msid('calc_pitch', '2020:001', '2020:002')

In [3]: dat1.msid
Out[3]: 'DP_pitch'

[javierggt]

if one is going to change it, perhaps it should be "normalized", meaning that the name is always the same for a given msid.

[taldcroft]

@javierggt - I think I addressed your concerns and made this a little better. The input msid is always left unchanged (when there is no fileglob *), and this user value is reflected in the plot title.

[taldcroft]

@javierggt @jeanconn - ping that this is ready for review and I addressed the initial comments.