This is an automated email from the git hooks/post-receive script. sf pushed a commit to annotated tag v1.33 in repository mapcode.
commit 78bed3db3291a0dc121359f6f0956c0e71753064 Author: Rijn Buve <[email protected]> Date: Thu Aug 21 10:45:04 2014 +0200 Added -g/--grid and -r/--random options --- mapcode.c | 106 +++++++++++++++++++++++++++++++++++++++++++------------------- 1 file changed, 73 insertions(+), 33 deletions(-) diff --git a/mapcode.c b/mapcode.c index fa54020..3e3d72e 100644 --- a/mapcode.c +++ b/mapcode.c @@ -21,19 +21,48 @@ static void usage(const char* appName) { printf(" Encode a lat/lon to a Mapcode. If the territory code is specified, the\n"); printf(" encoding will only succeeed if the lat/lon is located in the territory.\n"); printf("\n"); - printf(" %s [-g | --generate] <nrPoints> [<seed>]\n", appName); + printf(" %s [-g | --grid] <nrPoints> [<seed>]\n", appName); + printf(" %s [-r | --random] <nrPoints> [<seed>]\n", appName); printf("\n"); - printf(" Create a test set of a number of uniformly distributed lat/lon pairs,\n"); - printf(" 3D x/y/z points and their Mapcodes). The output format is:\n"); - printf(" <nr> <lat> <lon> <x> <y> <z>\n"); - printf(" <territory> <mapcode> (repeated 'nr' rtimes)\n"); - printf(" <1 empty line>\n"); + printf(" Create a test set of a number of a grid or random uniformly distributed\n"); + printf(" lat/lon pairs, (x, y, z) points and the Mapcode aliases.\n"); printf("\n"); - printf(" The points will be uniformly distributed over the 3D surface of the Earth\n"); - printf(" rather than using uniformly distributed lat/lon values.\n"); + printf(" The output format is:\n"); + printf(" <number-of-aliases> <lat-deg> <lon-deg> <x> <y> <z>\n"); + printf(" <territory> <mapcode> (repeated 'number-of-aliases' times)\n"); + printf(" (empty lines and next record)\n"); printf(" Ranges:\n"); - printf(" nr > 1 lat = -90..90 lon = -180..180 x,y,z = -1..1\n"); + printf(" number-of-aliases : >= 1\n"); + printf(" lat-deg, lon-deg : [-90..90], [-180..180]\n"); + printf(" x, y, z : [-1..1]\n"); printf("\n"); + printf(" The lat/lon pairs will be distributed over the 3D surface of the Earth\n"); + printf(" and the (x, y, z) coordinates are placed on a sphere with radius 1.\n"); +} + +/** + * Given a single number between 0..1, generate a latitude, longitude (in degrees) and a 3D + * (x, y, z) point on a sphere with a radius of 1. + */ +static void unitToLatLonDegXYZ( + const double unit, double* latDeg, double* lonDeg, double* x, double* y, double* z) { + + // Calculate uniformly distributed 3D point on sphere (radius = 1.0): + // http://mathproofs.blogspot.co.il/2005/04/uniform-random-distribution-on-sphere.html + const double theta0 = (2.0 * PI) * unit; + const double theta1 = acos(1.0 - (2.0 * unit)); + *x = sin(theta0) * sin(theta1); + *y = cos(theta0) * sin(theta1); + *z = cos(theta1); + + // Convert Carthesian 3D point into lat/lon (radius = 1.0): + // http://stackoverflow.com/questions/1185408/converting-from-longitude-latitude-to-cartesian-coordinates + const double latRad = asin(*z); + const double lonRad = atan2(*y, *x); + + // Convert radians to degrees. + *latDeg = latRad * (180.0 / PI); + *lonDeg = lonRad * (180.0 / PI); } int main(const int argc, const char** argv) @@ -53,6 +82,7 @@ int main(const int argc, const char** argv) // Decode: [-d | --decode] <default-territory> <mapcode> [<mapcode> ...] // ------------------------------------------------------------------ if (argc < 4) { + printf("error: incorrect number of arguments\n\n"); usage(appName); return -1; } @@ -76,6 +106,7 @@ int main(const int argc, const char** argv) // Encode: [-e | --encode] <lat:-90..90> <lon:-180..180> [territory]> // ------------------------------------------------------------------ if ((argc != 4) && (argc != 5)) { + printf("error: incorrect number of arguments\n\n"); usage(appName); return -1; } @@ -96,45 +127,53 @@ int main(const int argc, const char** argv) printf("%s %s\n", results[(i * 2) + 1], results[(i * 2)]); } } - else if ((strcmp(cmd, "-g") == 0) || (strcmp(cmd, "--generate") == 0)) { + else if ((strcmp(cmd, "-g") == 0) || (strcmp(cmd, "--grid") == 0) || + (strcmp(cmd, "-r") == 0) || (strcmp(cmd, "--random") == 0)) { // ------------------------------------------------------------------ - // Generate uniform test set: [-g | --generate] <nrPoints> [<seed>] + // Generate grid test set: [-g | --grid] <nrPoints> + // Generate uniform test set: [-r | --random] <nrPoints> [<seed>] // ------------------------------------------------------------------ - if ((argc != 3) && (argc != 4)) { + if ((argc < 3) || (argc > 4)) { + printf("error: incorrect number of arguments\n\n"); usage(appName); return -1; } const int nrPoints = atoi(argv[2]); - - if (argc == 4) { - const int seed = atoi(argv[3]); - srand(seed); + int random = (strcmp(cmd, "-r") == 0) || (strcmp(cmd, "--random") == 0); + if (random) { + if (argc == 4) { + const int seed = atoi(argv[3]); + srand(seed); + } + else { + srand(time(0)); + } } else { - srand(time(0)); + if (argc > 3) { + printf("error: cannot specify seed for -g/--grid\n\n"); + usage(appName); + return -1; + } } + const char* results[32]; int context = 0; - for (int i = 0; i < nrPoints; ++i) { - // Calculate uniformly distributed 3D point on sphere (radius = 1.0): - // http://mathproofs.blogspot.co.il/2005/04/uniform-random-distribution-on-sphere.html - const double unitRand = ((double) rand()) / RAND_MAX; - const double theta0 = (2.0 * PI) * unitRand; - const double theta1 = acos(1.0 - (2.0 * unitRand)); - const double x = sin(theta0) * sin(theta1); - const double y = cos(theta0) * sin(theta1); - const double z = cos(theta1); + double walker = 0.0; + const double increment = 1.0 / nrPoints; + + for (int i = 0; i < nrPoints; ++i) { - // Convert Carthesian 3D point into lat/lon (radius = 1.0): - // http://stackoverflow.com/questions/1185408/converting-from-longitude-latitude-to-cartesian-coordinates - const double latRad = asin(z); - const double lonRad = atan2(y, x); + double lat; + double lon; + double x; + double y; + double z; + double unit = (random ? (((double) rand()) / RAND_MAX) : walker); - // Convert radians to degrees. - const double lat = latRad * (180.0 / PI); - const double lon = lonRad * (180.0 / PI); + unitToLatLonDegXYZ(unit, &lat, &lon, &x, &y, &z); const int nrResults = coord2mc(results, lat, lon, context); if (nrResults <= 0) { @@ -146,6 +185,7 @@ int main(const int argc, const char** argv) printf("%s %s\n", results[(i * 2) + 1], results[(i * 2)]); } printf("\n"); + walker += increment; } } else { -- Alioth's /usr/local/bin/git-commit-notice on /srv/git.debian.org/git/pkg-grass/mapcode.git _______________________________________________ Pkg-grass-devel mailing list [email protected] http://lists.alioth.debian.org/cgi-bin/mailman/listinfo/pkg-grass-devel
