---
name: "GIS::Distance::ALT"
section: "3pm"
platform: "linux"
package: "libgis-distance-perl"
version: "0.20-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/GIS::Distance::ALT"
---

# GIS::Distance::ALT(3pm)

Andoyer-Lambert-Thomas distance calculations.

## NAME

GIS::Distance::ALT - Andoyer-Lambert-Thomas distance calculations.

## DESCRIPTION

The ALT formula is intended as a much faster, but slightly less accurate, alternative of the GIS::Distance::Vincenty formula. This formulas is about 5x faster than Vincenty.

The code for this formula was taken from Geo::Distance::XS and modified to fit.

A faster (XS) version of this formula is available as GIS::Distance::Fast::ALT.

Normally this module is not used directly.  Instead GIS::Distance is used which in turn interfaces with the various formula classes.

## SUPPORT

See "SUPPORT" in GIS::Distance.

## AUTHORS

See "AUTHORS" in GIS::Distance.

## LICENSE

See "LICENSE" in GIS::Distance.