Adding rcurve, rsphere, auxiliary latitudes, loxodrome_inverse, meanm, depature, meridianarc

[ryanpavlick]

Adding rcurve.py containing several functions that compute the radii of curvature for an ellipsoid.
Adding rsphere.py containing several functions that compute the radii of auxiliary spheres. Adding latitude.py containing several functions that compute auxiliary latitudes and their inverse functions.
Adding 'loxodrome_direct' to compute the end point of a loxodromic curve from a start lat/lon, azimuth, and distance.
Fixing 'loxodrome_inverse', it previously failed on the degenerate case of east/west azimuth. Adding 'meanm' which computes the geographic mean of points on a spheroid.
Adding 'departure' which computes the distance between two longitudes at a specified latitude. Adding 'meridianarc' which computes the distance between two latitudes along a specified longitude.
Added 'thirdflattening' and 'eccentricty' attributes to ellipsoid definitions.
Removed all instances of '%%' in comments.

[scivision]

This pull request introduces 17 alerts when merging 01daf11 into 5a0ca7b - view on LGTM.com

new alerts:

• 11 for Unused import
• 5 for Unused local variable
• 1 for Explicit export is not defined

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Comment posted by LGTM.com

[scivision]

This pull request introduces 6 alerts when merging 65ef88f into 5a0ca7b - view on LGTM.com

new alerts:

• 4 for Unused local variable
• 2 for Unused import

---

This project has automated code review enabled, but doesn't use the LGTM GitHub App. Migrate over by installing the app. Read about the benefits of migrating to GitHub Apps in the blog.

---

Comment posted by LGTM.com

[scivision]

This pull request introduces 1 alert when merging 982b946 into 5a0ca7b - view on LGTM.com

new alerts:

• 1 for Unused import

---

This project has automated code review enabled, but doesn't use the LGTM GitHub App. Migrate over by installing the app. Read about the benefits of migrating to GitHub Apps in the blog.

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Comment posted by LGTM.com

[scivision]

Thank you. The # %% are for IDEs such as
PyCharm
and
Spyder
that use # %% as a "code cell" analogous to IPython and Matlab.

[scivision]

I was working on this before the API internal change to make PyMap3D much more non-Numpy friendly, while still being Numpy, Pandas, Xarray friendly.
I was working through numerical accuracy bugs in the PR in the rcurve branch. I am a little short of time at the moment, but I intend to integrate your features along with the numerical fixes. Thanks for your contribution and patience

[scivision]

I think I will integrate these function by function. A lot of these are clearly working, but I had some questions over numerical stability of others. So I only add a function as I add tests for that function. You and/or others had recently pointed out numerical stability issues in older pymap3d functions so I don't want to add more issues.

[scivision]

all the auxilary latitude.py have been added. I think this will make the others go easier, as I fixed some trivial singularity stuff in them.

[scivision]

These have been incorporated in master branch. There were several errors in the code corrected along the way, as each function had a mini test suite created before adding.
We are putting the finishing touches on better numpy vs. No numpy compatibility before making a v2.1 release.

[scivision]

Thank you very much!