Add geodetic altitude to CSV log

[simfinite]

Hi,
I would like to have the geodetic altitude added to the CSV log. Besides my personal use cases, this may be helpful for future work on issue #184. Also, it'll simply make the log more complete.

I noticed, that the altitude AGL / distance above ground is currently being logged twice. I removed one of the entries in the second commit, because I think there shouldn't be any redundant data in the output file. If this shall be kept for backwards-compatibility, just omit the 2nd commit.

[simfinite]

Just realized I wasn't running all of the tests locally.. I can reproduce this now and will look into it.

[simfinite]

Ok, here is a new attempt. The failure of test case RunCheckCases was due to the reference log file check_cases/orbit/logged_data/BallOut.csv missing the new column. In order not to change the existing reference data (there are minor numerical differences when comparing to logs of the current version), I produced a new log, but only merged the new column into the existing file. Since this was a bit tricky to accomplish, here is the code I used:

new = pandas.read_csv("BallOut.new.csv", index_col="Time", float_precision='round_trip')
old = pandas.read_csv("BallOut.old.csv", index_col="Time", float_precision='round_trip')
merged = old.copy()
merged["Altitude Geodetic (ft)"] = new["Altitude Geodetic (ft)"]
merged.to_csv("BallOut.csv", float_format="%.16g")

It's a bit hard to see in a textual diff, but what this accomplishes is that all values of the old logfile are exactly preseverd, such that...

diff = merged.loc[:]-old.loc[:]
(diff == 0).all()

... outputs True for all columns but the new one (Altitude Geodetic (ft)).

I also found some comments listing the log columns, so I updated those.

The last commit still includes all changes to remove one of the duplicate altitude/distance AGL columns. May be omitted, if it's not desired to remove that column.

[simfinite]

hmm, the failures on Travis CI, I cannot reproduce reliably with my local setup. Although I have seen the segfault in TestInputSocket and also failure of CheckScripts occasionally when running tests in parallel with -j8.

[bcoconni]

You can get the same result when the property position/geod-alt-ft is specified in the <output> element :

<output name="result.csv" type="CSV" rate="10">
  <property> position/geod-alt-ft </property>
</output>

So there is no reason to add C++ code to get that value (and that saves the trouble about the file check_cases/orbit/logged_data/BallOut.csv).

[simfinite]

Ok, thank's for the help. I didn't know that one could specify additional properties, so that's good to know. For what it's worth, I still think removing the duplicate distance/altitude AGL would be an improvement to the C++ code, but probably not worth the trouble. Closing this now, as it's not required to be merged anymore.