Hi all I'm sorry for repeating the same question.
I tested by two kinds of geographical coordinate systems by using the same dat a. One of the geographical coordinate systems is UTM54, and the remainder is wgs8 4. data :point vector data (10 points) and a line vector data OS: grass 6.2.3 on Cygwin. As a result, the case of UTM54 obtained the distance of meter. On the other ha nd, wgs84 obtained the distance of decimal value. So, I guess that the decimal value of wgs84 is a degree of latitude longitude. Grass manual wrote that "...In lat-long locations v.distance gives distances ( dist and to_along) in meters not in degrees calculated as geodesic distances o n a sphere.." http://www.ces.iisc.ernet.in/grass/grass64/manuals/html64_user/v.distance.html Though this manual is version 6.4, the manual of version 6.2 is not written it . Is this interpretation correct? If it is so, please teach me the method of converting the decimal value into t he meter. ------------------- PROJCS["Transverse Mercator", GEOGCS["unnamed", DATUM["unknown", SPHEROID["unnamed",6378137,298.257222101], TOWGS84[0,0,0,0,0,0,0]], PRIMEM["Greenwich",0], UNIT["degree",0.0174532925199433]], PROJECTION["Transverse_Mercator"], PARAMETER["latitude_of_origin",0], PARAMETER["central_meridian",141], PARAMETER["scale_factor",0.9996], PARAMETER["false_easting",500000], PARAMETER["false_northing",0], UNIT["metre",1]] cat,UserID,distance 1,0,324.231475 2,0,170.339585 3,0,338.095708 4,0,347.756189 5,0,143.91159 6,0,156.702461 7,0,336.369666 8,0,178.761379 9,0,163.440513 10,0,122.997484 ------------------- GEOGCS["wgs84", DATUM["WGS_1984", SPHEROID["wgs84",6378137,298.257223563]], PRIMEM["Greenwich",0], UNIT["degree",0.0174532925199433]] cat,UserID,distance 1,0,0.003779 2,0,0.00198 3,0,0.003937 4,0,0.004053 5,0,0.001677 6,0,0.001826 7,0,0.003048 8,0,0.002084 9,0,0.001484 10,0,0.001113 ----------------- Yasuo shimada _______________________________________________ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user