cu_geos_cluster.c

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/**********************************************************************
 *
 * PostGIS - Spatial Types for PostgreSQL
 * http://postgis.net
 *
 * Copyright 2015 Daniel Baston
 *
 * This is free software; you can redistribute and/or modify it under
 * the terms of the GNU General Public Licence. See the COPYING file.
 *
 **********************************************************************/

#include "CUnit/Basic.h"

#include "../lwgeom_log.h"
#include "../lwgeom_geos.h"
#include "cu_tester.h"

static void assert_all_results_found(LWGEOM** results, size_t num_outputs, LWGEOM** expected, size_t num_expected_outputs)
{
        size_t i, j;

        char found_equal = 0;
        for (i = 0; i < num_outputs; i++)
        {
                for (j = 0; j < num_expected_outputs; j++)
                {
                        if (lwgeom_same(results[i], expected[j]))
                        {
                                found_equal = 1;
                                break;
                        }
                }

                CU_ASSERT_TRUE(found_equal);
        }
}

static GEOSGeometry** LWGEOMARRAY2GEOS(LWGEOM** lw_array, size_t num_geoms)
{
        size_t i;
        GEOSGeometry** geos_geoms = lwalloc(num_geoms * sizeof(GEOSGeometry*));

        for (i = 0; i < num_geoms; i++)
        {
                geos_geoms[i] = LWGEOM2GEOS(lw_array[i], 0);
        }

        return geos_geoms;
}

static LWGEOM** GEOSARRAY2LWGEOM(GEOSGeometry** geos_array, size_t num_geoms)
{
        size_t i;
        LWGEOM** lw_geoms = lwalloc(num_geoms * sizeof(LWGEOM*));

        for (i = 0; i < num_geoms; i++)
        {
                lw_geoms[i] = GEOS2LWGEOM(geos_array[i], 0);
        }

        return lw_geoms;
}

static LWGEOM** WKTARRAY2LWGEOM(char** wkt_array, size_t num_geoms)
{
        size_t i;

        LWGEOM** lw_geoms = lwalloc(num_geoms * sizeof(LWGEOM*));

        for (i = 0; i < num_geoms; i++)
        {
                lw_geoms[i] = lwgeom_from_wkt(wkt_array[i], LW_PARSER_CHECK_NONE);
        }

        return lw_geoms;
}

static void perform_cluster_intersecting_test(char** wkt_inputs, uint32_t num_inputs, char** wkt_outputs, uint32_t num_outputs)
{
        GEOSGeometry** geos_results;
        LWGEOM** lw_results;
        uint32_t num_clusters;

        LWGEOM** expected_outputs = WKTARRAY2LWGEOM(wkt_outputs, num_outputs);
        LWGEOM** lw_inputs = WKTARRAY2LWGEOM(wkt_inputs, num_inputs);
        GEOSGeometry** geos_inputs = LWGEOMARRAY2GEOS(lw_inputs, num_inputs);

        cluster_intersecting(geos_inputs, num_inputs, &geos_results, &num_clusters);
        CU_ASSERT_EQUAL(num_outputs, num_clusters);

        lw_results = GEOSARRAY2LWGEOM(geos_results, num_clusters);

        assert_all_results_found(lw_results, num_clusters, expected_outputs, num_outputs);

        /* Cleanup */
        uint32_t i;
        for(i = 0; i < num_clusters; i++)
        {
                GEOSGeom_destroy(geos_results[i]);
        }
        lwfree(geos_inputs);
        lwfree(geos_results);

        for(i = 0; i < num_outputs; i++)
        {
                lwgeom_free(expected_outputs[i]);
                lwgeom_free(lw_results[i]);
        }
        lwfree(expected_outputs);
        lwfree(lw_results);

        for(i = 0; i < num_inputs; i++)
        {
                lwgeom_free(lw_inputs[i]);
        }
        lwfree(lw_inputs);
}

static void perform_cluster_within_distance_test(double tolerance, char** wkt_inputs, uint32_t num_inputs, char** wkt_outputs, uint32_t num_outputs)
{
        LWGEOM** lw_results;
        uint32_t num_clusters;

        LWGEOM** expected_outputs = WKTARRAY2LWGEOM(wkt_outputs, num_outputs);
        LWGEOM** lw_inputs = WKTARRAY2LWGEOM(wkt_inputs, num_inputs);

        cluster_within_distance(lw_inputs, num_inputs, tolerance, &lw_results, &num_clusters);

        CU_ASSERT_EQUAL(num_outputs, num_clusters);

        assert_all_results_found(lw_results, num_clusters, expected_outputs, num_outputs);

        /* Cleanup */
        uint32_t i;
        for(i = 0; i < num_outputs; i++)
        {
                lwgeom_free(expected_outputs[i]);
                lwgeom_free(lw_results[i]);
        }
        lwfree(lw_results);
        lwfree(expected_outputs);
        lwfree(lw_inputs);
}

static int init_geos_cluster_suite(void)
{
        initGEOS(lwnotice, lwgeom_geos_error);
        return 0;
}

static int clean_geos_cluster_suite(void)
{
        finishGEOS();
        return 0;
}

static void basic_test(void)
{
        char* a = "LINESTRING (0 0, 1 1)";
        char* b = "LINESTRING (1 1, 2 2)";
        char* c = "LINESTRING (5 5, 6 6)";

        char* wkt_inputs_a[] = {a, b, c};
        char* wkt_inputs_b[] = {b, c, a};
        char* wkt_inputs_c[] = {c, a, b};

        char* expected_outputs_a[] = { "GEOMETRYCOLLECTION(LINESTRING (0 0, 1 1), LINESTRING (1 1, 2 2))",
                                       "GEOMETRYCOLLECTION(LINESTRING (5 5, 6 6))"
                                     };

        char* expected_outputs_b[] = { "GEOMETRYCOLLECTION(LINESTRING (1 1, 2 2), LINESTRING (0 0, 1 1))",
                                       "GEOMETRYCOLLECTION(LINESTRING (5 5, 6 6))"
                                     };

        char* expected_outputs_c[] = { "GEOMETRYCOLLECTION(LINESTRING (0 0, 1 1), LINESTRING (1 1, 2 2))",
                                       "GEOMETRYCOLLECTION(LINESTRING (5 5, 6 6))"
                                     };

        perform_cluster_intersecting_test(wkt_inputs_a, 3, expected_outputs_a, 2);
        perform_cluster_intersecting_test(wkt_inputs_b, 3, expected_outputs_b, 2);
        perform_cluster_intersecting_test(wkt_inputs_c, 3, expected_outputs_c, 2);

        perform_cluster_within_distance_test(0, wkt_inputs_a, 3, expected_outputs_a, 2);
        perform_cluster_within_distance_test(0, wkt_inputs_b, 3, expected_outputs_b, 2);
        perform_cluster_within_distance_test(0, wkt_inputs_c, 3, expected_outputs_c, 2);
}

static void basic_distance_test(void)
{
        char* a = "LINESTRING (0 0, 1 1)";
        char* b = "LINESTRING (1 1, 2 2)";
        char* c = "LINESTRING (5 5, 6 6)";

        char* wkt_inputs[] = {a, b, c};

        char* expected_outputs_all[] = {"GEOMETRYCOLLECTION(LINESTRING(0 0, 1 1), LINESTRING(1 1, 2 2), LINESTRING(5 5, 6 6))"};
        char* expected_outputs_partial[] = {"GEOMETRYCOLLECTION(LINESTRING(0 0, 1 1), LINESTRING(1 1, 2 2))",
                                            "GEOMETRYCOLLECTION(LINESTRING(5 5, 6 6))"
                                           };

        perform_cluster_within_distance_test(0, wkt_inputs, 3, expected_outputs_partial, 2);
        perform_cluster_within_distance_test(sqrt(18) - 0.0000001, wkt_inputs, 3, expected_outputs_partial, 2);
        perform_cluster_within_distance_test(sqrt(18) + 0.0000001, wkt_inputs, 3, expected_outputs_all, 1);
}

static void nonsequential_test(void)
{
        char* wkt_inputs[] = { "LINESTRING (0 0, 1 1)",
                               "LINESTRING (1 1, 2 2)",
                               "LINESTRING (5 5, 6 6)",
                               "LINESTRING (5 5, 4 4)",
                               "LINESTRING (3 3, 2 2)",
                               "LINESTRING (3 3, 4 4)"
                             };

        char* expected_outputs[] = { "GEOMETRYCOLLECTION (LINESTRING (0 0, 1 1), LINESTRING (1 1, 2 2), LINESTRING (5 5, 6 6), LINESTRING (5 5, 4 4), LINESTRING (3 3, 2 2), LINESTRING (3 3, 4 4))" };

        perform_cluster_intersecting_test(wkt_inputs, 6, expected_outputs, 1);
        perform_cluster_within_distance_test(0, wkt_inputs, 6, expected_outputs, 1);
}

static void single_input_test(void)
{
        char* wkt_inputs[] = { "POINT (0 0)" };
        char* expected_outputs[] = { "GEOMETRYCOLLECTION (POINT (0 0))" };

        perform_cluster_intersecting_test(wkt_inputs, 1, expected_outputs, 1);
        perform_cluster_within_distance_test(1, wkt_inputs, 1, expected_outputs, 1);
}

static void empty_inputs_test(void)
{
        char* wkt_inputs[] = { "POLYGON EMPTY", "LINESTRING EMPTY"};
        char* expected_outputs[] = { "GEOMETRYCOLLECTION( LINESTRING EMPTY )", "GEOMETRYCOLLECTION( POLYGON EMPTY )" };

        perform_cluster_intersecting_test(wkt_inputs, 2, expected_outputs, 2);
        perform_cluster_within_distance_test(1, wkt_inputs, 2, expected_outputs, 2);
}

static void multipoint_test(void)
{
        /* See #3433 */
        char* wkt_inputs_mp[] = { "MULTIPOINT ((0 0), (0 1))", "POINT (0 0)"};
        char* expected_outputs_mp[] = { "GEOMETRYCOLLECTION(MULTIPOINT ((0 0), (0 1)), POINT (0 0))"};

        char* wkt_inputs_gc[] = { "GEOMETRYCOLLECTION (POINT (0 0), POINT (0 1))", "POINT (0 0)"};
        char* expected_outputs_gc[] = { "GEOMETRYCOLLECTION(GEOMETRYCOLLECTION (POINT (0 0), POINT (0 1)), POINT (0 0))"};

        char* wkt_inputs_pt[] = { "POINT (3 3)", "POINT (3 3)"};
        char* expected_outputs_pt[] = { "GEOMETRYCOLLECTION(POINT (3 3), POINT (3 3))"};

        perform_cluster_intersecting_test(wkt_inputs_mp, 2, expected_outputs_mp, 1);
        perform_cluster_intersecting_test(wkt_inputs_gc, 2, expected_outputs_gc, 1);
        perform_cluster_intersecting_test(wkt_inputs_pt, 2, expected_outputs_pt, 1);
}

struct dbscan_test_info {
        double eps;
        uint32_t min_points;
        uint32_t num_geoms;
        char** wkt_inputs;
        uint32_t* expected_ids;
        int* expected_in_cluster;
};

static void do_dbscan_test(struct dbscan_test_info test)
{
        LWGEOM** geoms = WKTARRAY2LWGEOM(test.wkt_inputs, test.num_geoms);
        UNIONFIND* uf = UF_create(test.num_geoms);
        uint32_t* ids;
        char* in_a_cluster;
        uint32_t i;

        union_dbscan(geoms, test.num_geoms, uf, test.eps, test.min_points, &in_a_cluster);
        ids = UF_get_collapsed_cluster_ids(uf, in_a_cluster);

        for (i = 0; i < test.num_geoms; i++)
        {
                ASSERT_INT_EQUAL(in_a_cluster[i], test.expected_in_cluster[i]);
                if (in_a_cluster[i])
                        ASSERT_INT_EQUAL(ids[i], test.expected_ids[i]);
        }

        UF_destroy(uf);
        for (i = 0; i < test.num_geoms; i++)
        {
                lwgeom_free(geoms[i]);
        }
        lwfree(geoms);
        lwfree(in_a_cluster);
        lwfree(ids);
}

static void dbscan_test(void)
{
        struct dbscan_test_info test;
        char* wkt_inputs[] = { "POINT (0 0)", "POINT (-1 0)", "POINT (-1 -0.1)", "POINT (-1 0.1)",
                                   "POINT (1 0)",
                                                   "POINT (2 0)", "POINT (3  0)", "POINT ( 3 -0.1)", "POINT ( 3 0.1)" };
        /* Although POINT (1 0) and POINT (2 0) are within eps distance of each other,
         * they do not connect the two clusters because POINT (1 0) is not a core point.
         * See #3572
         */
        test.eps = 1.01;
        test.min_points = 5;
        uint32_t expected_ids[] =   { 0, 0, 0, 0, 0, 1, 1, 1, 1, 1 };
        int expected_in_cluster[] = { 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 };
        test.num_geoms = sizeof(wkt_inputs) / sizeof(char*);

        test.expected_ids = expected_ids;
        test.wkt_inputs = wkt_inputs;
        test.expected_in_cluster = expected_in_cluster;
        do_dbscan_test(test);
}

static void dbscan_test_3612a(void)
{
        struct dbscan_test_info test;
        char* wkt_inputs[] = { "POINT (1 1)" };

        test.eps = 0.0;
        test.min_points = 5;
        uint32_t expected_ids[] = { rand() };
        int expected_in_cluster[] = { 0 };
        test.num_geoms = sizeof(wkt_inputs) / sizeof(char*);

        test.expected_ids = expected_ids;
        test.expected_in_cluster = expected_in_cluster;
        test.wkt_inputs = wkt_inputs;
        do_dbscan_test(test);
}

static void dbscan_test_3612b(void)
{
        struct dbscan_test_info test;
        char* wkt_inputs[] = { "POINT (1 1)" };

        test.eps = 0.0;
        test.min_points = 1;
        uint32_t expected_ids[]   = { 0 };
        int expected_in_cluster[] = { 1 };
        test.num_geoms = sizeof(wkt_inputs) / sizeof(char*);

        test.expected_ids = expected_ids;
        test.expected_in_cluster = expected_in_cluster;
        test.wkt_inputs = wkt_inputs;
        do_dbscan_test(test);
}

static void dbscan_test_3612c(void)
{
        struct dbscan_test_info test;
        char* wkt_inputs[] = { "POLYGONM((-71.1319 42.2503 1,-71.132 42.2502 3,-71.1323 42.2504 -2,-71.1322 42.2505 1,-71.1319 42.2503 0))",
                                                   "POLYGONM((-71.1319 42.2512 0,-71.1318 42.2511 20,-71.1317 42.2511 -20,-71.1317 42.251 5,-71.1317 42.2509 4,-71.132 42.2511 6,-71.1319 42.2512 30))" };
        test.eps = 20.1;
        test.min_points = 5;
        uint32_t expected_ids[]   = { rand(), rand() };
        int expected_in_cluster[] = { 0, 0 };
        test.num_geoms = sizeof(wkt_inputs) / sizeof(char*);

        test.expected_ids = expected_ids;
        test.expected_in_cluster = expected_in_cluster;
        test.wkt_inputs = wkt_inputs;
        do_dbscan_test(test);
}

void geos_cluster_suite_setup(void);
void geos_cluster_suite_setup(void)
{
        CU_pSuite suite = CU_add_suite("Clustering", init_geos_cluster_suite, clean_geos_cluster_suite);
        PG_ADD_TEST(suite, basic_test);
        PG_ADD_TEST(suite, nonsequential_test);
        PG_ADD_TEST(suite, basic_distance_test);
        PG_ADD_TEST(suite, single_input_test);
        PG_ADD_TEST(suite, empty_inputs_test);
        PG_ADD_TEST(suite, multipoint_test);
        PG_ADD_TEST(suite, dbscan_test);
        PG_ADD_TEST(suite, dbscan_test_3612a);
        PG_ADD_TEST(suite, dbscan_test_3612b);
        PG_ADD_TEST(suite, dbscan_test_3612c);
}