Example not working

[chris-haste]

Hi,

Using the latest version 0.7.5 the below example fails:

wgs84 = nv.FrameE(name='WGS84')
point1 = wgs84.GeoPoint(latitude=88, longitude=0, degrees=True)
point2 = wgs84.GeoPoint(latitude=89, longitude=-170, degrees=True)
s_12, _azi1, _azi2 = point1.distance_and_azimuth(point2)
p_12_E = point2.to_ecef_vector() - point1.to_ecef_vector()
d_12 = p_12_E.length[0]
msg = 'Ellipsoidal and Euclidean distance = {:5.2f} km, {:5.2f} km'
msg.format(s_12 / 1000, d_12 / 1000)

The error given is:

Attribute Error: 'list' object has no attribute 'T'

The example works correctly with version 0.7.4

[pbrod]

I get:

(base) PS C:\Users\peran\Documents\workspace\nvector> ipython                                                           Python 3.7.6 (default, Jan  8 2020, 20:23:39) [MSC v.1916 64 bit (AMD64)]
Type 'copyright', 'credits' or 'license' for more information
IPython 7.12.0 -- An enhanced Interactive Python. Type '?' for help.

In [1]: import nvector as nv

In [2]: nv.__version__
Out[2]: '0.7.5'

In [3]: wgs84 = nv.FrameE(name='WGS84')^M
   ...: point1 = wgs84.GeoPoint(latitude=88, longitude=0, degrees=True)^M
   ...: point2 = wgs84.GeoPoint(latitude=89, longitude=-170, degrees=True)^M
   ...: s_12, _azi1, _azi2 = point1.distance_and_azimuth(point2)^M
   ...: p_12_E = point2.to_ecef_vector() - point1.to_ecef_vector()^M
   ...: d_12 = p_12_E.length[0]^M
   ...: msg = 'Ellipsoidal and Euclidean distance = {:5.2f} km, {:5.2f} km'^M
   ...: msg.format(s_12 / 1000, d_12 / 1000)
---------------------------------------------------------------------------
IndexError                                Traceback (most recent call last)
<ipython-input-3-accdc39bf2e9> in <module>
      4 s_12, _azi1, _azi2 = point1.distance_and_azimuth(point2)
      5 p_12_E = point2.to_ecef_vector() - point1.to_ecef_vector()
----> 6 d_12 = p_12_E.length[0]
      7 msg = 'Ellipsoidal and Euclidean distance = {:5.2f} km, {:5.2f} km'
      8 msg.format(s_12 / 1000, d_12 / 1000)

IndexError: invalid index to scalar variable.

[pbrod]

This is as expected and is due to the change described in issue #10. If you give scalar input in, you will get scalar output. Likewise, if you give vector input, you get vector output. In this particular example line 6 must be changed to

d_12 = p_12_E.length

without the bracket indexing.