Rainsford line (e), International ellipsoid Rainsford line (d), International ellipsoid Rainsford line (c), International ellipsoid Rainsford line (b), International ellipsoid * on the ellipsoid with application of nested equations, Survey Review 22(176): (1975) Direct and inverse solutions of geodesics * Duplicate all 5 examples Vincenty used to compare his results with those of Here's a small subset:Ĭode: * Choose to run this script under the executable versionĬscript "geodist - Stata version `c(stata_version)' " adofile geodist With respect to the validity of the results produced by my programs, I'm always happy to provide all certification scripts that I use upon request. That's because ArcGIS works with projected coordinate systems. I'm no expert on ArcGIS, but as far as I can tell, ArcGIS has historically calculated Euclidean distances between features.
The Haversine and Laws of Cosine equations (which are mathematically equivalent) are used if the earth is modeled as a sphere. By default, the shape of the earth is approximated using the WGS 1984 reference ellipsoid (what GPS devices and Google Earth/Map use) and distances are computed using Vincenty's inverse solution equations. Both are available from SSC.Īs explained in detail in the help file, geodist calculates the length of the shortest curve between two points along the surface of a mathematical model of the earth. This item may be available elsewhere in EconPapers: Search for items with the same title.I'm the author of geodist, which is a standalone version of the distance routines I wrote for geonear, a program that finds nearest neighbors using geodetic distances.
Windows users should not attempt to download these files with a web browser.Ĭitations: View citations in EconPapers (19) Track citations by RSS feed The module is made available under terms of the GPL v3 ().
Note: This module should be installed from within Stata by typing "ssc install geodist". Keywords: geodetic geodesic Vincenty great-circle ellipsoid distance (search for similar items in EconPapers) geodist can also calculate great-circle distances using the haversine formula.
By default, geodist implements Vincenty's (1975) formula to calculate distances on a reference ellipsoid.
Geodist calculates geographical distances by measuring the length of the shortest path between two points along the surface of a mathematical model of the earth.
Statistical Software Components from Boston College Department of Economics GEODIST: Stata module to compute geographical distances