Few questions about parameters

[Racum]

Hello @damody, this code looks promising, but I need some context; can you answer a few questions to help me understand it?

• About lnglat_to_mercator:
  • Are lng and lat units in degrees?
  • Is the unit of the return value in meters?
• About mercator_to_lnglat:
  • Are x and x units in meters?
  • Is the unit of the return value in degrees?
• Both lnglat_to_mercator and mercator_to_lnglat:
  • Is center_lng the φ (phi) angle from this diagram?
  • What does k0 and dx mean in this context?
• License:
  • Is this code free to use?
  • Can you drop a LICENSE file in the repo just to clarify it?

Thanks in advance!

[damody]

Hello @damody, this code looks promising, but I need some context; can you answer a few questions to help me understand it?

• About lnglat_to_mercator:
  • Are lng and lat units in degrees? yes
  • Is the unit of the return value in meters? yes
• About mercator_to_lnglat:
  • Are x and x units in meters? yes
  • Is the unit of the return value in degrees? yes
• Both lnglat_to_mercator and mercator_to_lnglat:
  • Is center_lng the φ (phi) angle from this diagram?
    Time is too long I forgot.
  • What does k0 and dx mean in this context?
    Because the earth is elliptical, k0 is the ellipse parameter
    dx is False easting
    center_lng is centered on a lng
    Can refer to
    https://georepository.com/projection_3820/Taiwan-2-degree-TM-zone-121.html
• License:
  • Is this code free to use?
  • Can you drop a LICENSE file in the repo just to clarify it?
    I add BSD.