Latitude Band Open Pole Membership Tool

Description

Test both boundaries with independent inclusion flags and return pole when absolute latitude is exactly 90.

Latitude bands use ordered north/south angular bounds. Coordinate midpoints and membership describe the angular axis; they do not automatically describe an equal-area center or the boundary of a real region.

Test both boundaries with independent inclusion flags and return pole when absolute latitude is exactly 90.

When to use this tool

Use Latitude Band Open Pole Membership when you need a supplied latitude-band comparison or midpoint.

How to use the tool and how it works

Enter latitude, south, north, includeSouth, includeNorth. Use the units and conventions below.
Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
Read inside, pole. Inspect inside, pole before interpreting the associated values.

Require bounded latitude and an ordered south less than north band within [-90, 90]. Test both boundaries with independent inclusion flags and return pole when absolute latitude is exactly 90.^[1]

Input field	Meaning and units	Accepted input
latitude	Latitude	Required. Finite number; minimum -90; maximum 90.
south	South	Required. Finite number; minimum -90.
north	North	Required. Finite number; maximum 90.
includeSouth	Include South	Required. Boolean.
includeNorth	Include North	Required. Boolean.

Output field	Interpretation	Returned shape
inside	Inside	Required. Boolean.
pole	Pole	Required. Boolean.

json

{
  "input": {
    "latitude": 90,
    "south": 80,
    "north": 90,
    "includeSouth": true,
    "includeNorth": false
  },
  "output": {
    "inside": false,
    "pole": true
  }
}

Limitations and assumptions

Pole reports the input point, independently of whether it belongs to the band. Inputs use degrees; band membership is not an area calculation or an actual-region check.
Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.

Alternative or Complementary methods

Use the actual regional geometry or a spherical/ellipsoidal area method when area and spatial extent matter. Keep endpoint inclusion and angular units explicit.

References

Calculation and input contract: geography/latitude-band-open-pole-membership — tool.io

Similar or alternative tools

Latitude Band Center
Return their arithmetic mean and half their difference.
Geography: Latitude Pole Reflection Step
Reflect a latitude beyond a pole once, add 180 degrees of longitude when reflected, and normalize longitude into [-180, 180).