This is a file from the Wikimedia Commons
From Wikipedia, the free encyclopedia

Original file(SVG file, nominally 540 × 360 pixels, file size: 47 KB)

Summary

Description
English: Graph of the difference between geodetic latitude and five auxiliary latitudes on the WGS 84 ellipsoid. Conformal and Geocentric are indistinguishable at this resolution.
Date
Source Own work
Author Apocheir
SVG development
InfoField
 
The source code of this SVG is invalid due to an error.
 
This W3C-invalid plot was created with Matplotlib.
Source code
InfoField

Python code

mport numpy as np
from scipy.special import ellipeinc
import matplotlib.pyplot as plt

f = 1/298.257223563
esq = f*(2-f)
e = np.sqrt(esq)

def gd(x):
    return 2*np.arctan(np.tanh(x/2))

def gdinv(x):
    return 2*np.arctanh(np.tan(x/2))

npts = 181
geodetic = np.linspace(0,np.pi/2,npts)
geocentric = np.arctan((1-f)**2 * np.tan(geodetic))
parametric = np.arctan((1-f) * np.tan(geodetic))
m = (ellipeinc(geodetic, esq) -
     esq * np.sin(geodetic) * np.cos(geodetic) / 
     np.sqrt(1 - esq * np.sin(geodetic)**2))
rectifying = np.pi/2*m/m.max()
qp = 1 + (1-esq)/e*np.arctanh(e)
q = ((1 - esq)*np.sin(geodetic)/(1 - esq*np.sin(geodetic)**2) + 
     (1 - esq)/e*np.arctanh(e*np.sin(geodetic)))
authalic = np.arcsin(q/qp)
conformal = gd(gdinv(geodetic) - e * np.arctanh(e*np.sin(geodetic)))

gddegrees = np.linspace(0,90,npts)
gdmindiff = np.zeros(gddegrees.shape)
parmindiff = 10800/np.pi*(parametric - geodetic)
autmindiff = 10800/np.pi*(authalic - geodetic)
recmindiff = 10800/np.pi*(rectifying - geodetic)
conmindiff = 10800/np.pi*(conformal - geodetic)
gcmindiff = 10800/np.pi*(geocentric - geodetic)

fig = plt.figure()
ax = plt.axes()
#in this order so conformal and geocentric get contrasting colors
ax.plot(gddegrees, conmindiff, label='conformal', dashes=4, 4])
ax.plot(gddegrees, gcmindiff, label='geocentric', dashes=0, 4, 4, 0])
ax.plot(gddegrees, gdmindiff, label='geodetic')
ax.plot(gddegrees, parmindiff, label='parametric')
ax.plot(gddegrees, autmindiff, label='authalic')
ax.plot(gddegrees, recmindiff, label='rectifying')
bbox = dict(color='white', alpha=0)
ax.text(45, -0.1, 'Geodetic', bbox=bbox,
        horizontalalignment='center', verticalalignment='top')
ax.text(45, min(parmindiff) + 0.2, 'Parametric', bbox=bbox, 
        horizontalalignment='center', verticalalignment='bottom')
ax.text(45, min(autmindiff) + 0.15, 'Authalic', bbox=bbox, 
        horizontalalignment='center', verticalalignment='bottom')
ax.text(45, min(recmindiff) + 0.25, 'Rectifying', bbox=bbox, 
        horizontalalignment='center', verticalalignment='bottom')
ax.text(45, min(gcmindiff) + 0.35, 'Conformal/\nGeocentric', bbox=bbox,
        horizontalalignment='center', verticalalignment='bottom')
ax.set(xlim=(0, 90),
       xlabel='Geodetic latitude (degrees)', 
       ylabel='Difference from geodetic latitude (minutes)',
       title='Auxiliary latitudes');
ax.xaxis.set_major_locator(plt.MaxNLocator(7))
plt.savefig("Auxiliary Latitudes Difference.svg")

Licensing

I, the copyright holder of this work, hereby publish it under the following license:
Creative Commons CC-Zero This file is made available under the Creative Commons CC0 1.0 Universal Public Domain Dedication.
The person who associated a work with this deed has dedicated the work to the public domain by waiving all of their rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law. You can copy, modify, distribute and perform the work, even for commercial purposes, all without asking permission.

Information

Captions

Graph of the difference between geodetic latitude and five auxiliary latitudes

Items portrayed in this file

depicts

5 September 2019

image/svg+xml

a14e7ca30f021e11bc5754bbcea9f67496946949

47,959 byte

360 pixel

540 pixel

File history

Click on a date/time to view the file as it appeared at that time.

Date/TimeThumbnailDimensionsUserComment
current 23:24, 5 September 2019 Thumbnail for version as of 23:24, 5 September 2019540 × 360 (47 KB)ApocheirUser created page with UploadWizard
The following pages on the English Wikipedia use this file (pages on other projects are not listed):

Global file usage

The following other wikis use this file:

  • Usage on es.wikipedia.org
  • Usage on ja.wikipedia.org

Metadata