Description
Compute the eastward wrapped longitude span, take its halfway point, and normalize into [-180, 180).
Longitude is an angular coordinate with a seam and equivalent values separated by full turns. Interval direction, endpoint inclusion, and half-turn policy must be fixed before comparing or averaging longitudes.
Compute the eastward wrapped longitude span, take its halfway point, and normalize into [-180, 180).
When to use this tool
Use Geography: Geographic Cell Angular Center when you need a longitude normalization, interval, or seam-policy calculation.
How to use the tool and how it works
- Enter southDegrees, northDegrees, westDegrees, eastDegrees. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read result. Expand result to inspect the returned fields.
Require ordered bounded latitude limits and bounded longitude limits, reject longitude differences of exactly ±360, and average latitude. Compute the eastward wrapped longitude span, take its halfway point, and normalize into [-180, 180).1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| southDegrees | South Degrees Unit: deg. | Required. Finite number. |
| northDegrees | North Degrees Unit: deg. | Required. Finite number. |
| westDegrees | West Degrees Unit: deg. | Required. Finite number. |
| eastDegrees | East Degrees Unit: deg. | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| result | Object containing the calculated members; expand to inspect the fields below. | Required. Object. |
| result.latitudeDegrees | Latitude Degrees | Calculated result member: number. |
| result.longitudeDegrees | Longitude Degrees | Calculated result member: number. |
{
"input": {
"southDegrees": 0,
"northDegrees": 10,
"westDegrees": 170,
"eastDegrees": -170
},
"output": {
"result": {
"latitudeDegrees": 5,
"longitudeDegrees": -180
}
}
}Limitations and assumptions
- Equal longitude endpoints mean zero width; seam-spanning intervals use the wrapped arc. The midpoint is angular, not an area centroid or ellipsoidal center.
- Outputs are nested inside result. 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 a full spherical or ellipsoidal geometry method for routes and areas. Retain an explicit seam and endpoint policy when splitting, sorting, or averaging geographic data.
References
Similar or alternative tools
- Geographic Point Antimeridian Alias Pair
Return west [-180, latitude] and east [180, latitude] as longitude-first pairs.
- Longitude Cell Half Open Membership
Test membership in the west-inclusive, east-exclusive interval, using a union across the seam when west exceeds east.