Examples with DBIDArrayIter de.lmu.ifi.dbs.elki.database.ids.DBIDArrayIter used on opensource projects

Example 16 with DBIDArrayIter

use of de.lmu.ifi.dbs.elki.database.ids.DBIDArrayIter in project elki by elki-project.

the class WeightedQuickUnionRangeDBIDsTest method testWorstCase.

/**
 * Worst-case with 10 nodes, from Sedgewick.
 *
 * We don't test runtime, but this is an interesting case nevertheless.
 */
@Test
public void testWorstCase() {
    DBIDRange range = DBIDUtil.generateStaticDBIDRange(10);
    UnionFind uf = new WeightedQuickUnionRangeDBIDs(range);
    DBIDArrayIter i1 = range.iter(), i2 = range.iter();
    assertFalse(uf.isConnected(i1.seek(0), i2.seek(1)));
    uf.union(i1.seek(0), i2.seek(1));
    assertTrue(uf.isConnected(i1.seek(0), i2.seek(1)));
    uf.union(i1.seek(2), i2.seek(3));
    assertFalse(uf.isConnected(i1.seek(0), i2.seek(2)));
    uf.union(i1.seek(5), i2.seek(4));
    uf.union(i1.seek(7), i2.seek(6));
    uf.union(i1.seek(8), i2.seek(9));
    uf.union(i1.seek(1), i2.seek(3));
    assertTrue(uf.isConnected(i1.seek(0), i2.seek(2)));
    uf.union(i1.seek(4), i2.seek(6));
    assertTrue(uf.isConnected(i1.seek(5), i2.seek(7)));
    uf.union(i1.seek(3), i2.seek(7));
    assertTrue(uf.isConnected(i1.seek(0), i2.seek(4)));
    assertFalse(uf.isConnected(i1.seek(0), i2.seek(9)));
    uf.union(i1.seek(0), i2.seek(9));
    for (int i = 0; i < 8; i++) {
        for (int j = 0; j < 8; j++) {
            assertTrue(uf.isConnected(i1.seek(i), i2.seek(j)));
        }
    }
}

Example 17 with DBIDArrayIter

use of de.lmu.ifi.dbs.elki.database.ids.DBIDArrayIter in project elki by elki-project.

the class WeightedQuickUnionRangeDBIDsTest method testRoots.

@Test
public void testRoots() {
    DBIDRange range = DBIDUtil.generateStaticDBIDRange(8);
    UnionFind uf = new WeightedQuickUnionRangeDBIDs(range);
    DBIDArrayIter i1 = range.iter(), i2 = range.iter();
    uf.union(i1.seek(0), i2.seek(1));
    uf.union(i1.seek(2), i2.seek(3));
    assertEquals(6, uf.getRoots().size());
    uf.union(i1.seek(0), i2.seek(2));
    assertEquals(5, uf.getRoots().size());
    uf.union(i1.seek(4), i2.seek(5));
    uf.union(i1.seek(6), i2.seek(7));
    uf.union(i1.seek(4), i2.seek(6));
    assertEquals(2, uf.getRoots().size());
    uf.union(i1.seek(0), i2.seek(4));
    assertEquals(1, uf.getRoots().size());
}

Example 18 with DBIDArrayIter

use of de.lmu.ifi.dbs.elki.database.ids.DBIDArrayIter in project elki by elki-project.

the class WeightedQuickUnionStaticDBIDsTest method testWorstCase.

/**
 * Worst-case with 10 nodes, from Sedgewick.
 *
 * We don't test runtime, but this is an interesting case nevertheless.
 */
@Test
public void testWorstCase() {
    DBIDRange range = DBIDUtil.generateStaticDBIDRange(10);
    UnionFind uf = new WeightedQuickUnionStaticDBIDs(range);
    DBIDArrayIter i1 = range.iter(), i2 = range.iter();
    assertFalse(uf.isConnected(i1.seek(0), i2.seek(1)));
    uf.union(i1.seek(0), i2.seek(1));
    assertTrue(uf.isConnected(i1.seek(0), i2.seek(1)));
    uf.union(i1.seek(2), i2.seek(3));
    assertFalse(uf.isConnected(i1.seek(0), i2.seek(2)));
    uf.union(i1.seek(5), i2.seek(4));
    uf.union(i1.seek(7), i2.seek(6));
    uf.union(i1.seek(8), i2.seek(9));
    uf.union(i1.seek(1), i2.seek(3));
    assertTrue(uf.isConnected(i1.seek(0), i2.seek(2)));
    uf.union(i1.seek(4), i2.seek(6));
    assertTrue(uf.isConnected(i1.seek(5), i2.seek(7)));
    uf.union(i1.seek(3), i2.seek(7));
    assertTrue(uf.isConnected(i1.seek(0), i2.seek(4)));
    assertFalse(uf.isConnected(i1.seek(0), i2.seek(9)));
    uf.union(i1.seek(0), i2.seek(9));
    for (int i = 0; i < 8; i++) {
        for (int j = 0; j < 8; j++) {
            assertTrue(uf.isConnected(i1.seek(i), i2.seek(j)));
        }
    }
}

Example 19 with DBIDArrayIter

use of de.lmu.ifi.dbs.elki.database.ids.DBIDArrayIter in project elki by elki-project.

the class WeightedQuickUnionStaticDBIDsTest method testBruteForce.

@Test
public void testBruteForce() {
    final Random r = new Random(0L);
    final int size = 100;
    DBIDRange range = DBIDUtil.generateStaticDBIDRange(size);
    UnionFind uf = new WeightedQuickUnionStaticDBIDs(range);
    DBIDArrayIter i1 = range.iter(), i2 = range.iter();
    int[] c = new int[size];
    for (int i = 0; i < size; i++) {
        c[i] = i;
    }
    int numc = size;
    while (numc > 1) {
        // Two randoms, with o1 < o2
        int o2 = r.nextInt(size - 1) + 1, o1 = r.nextInt(o2);
        final int c1 = c[o1], c2 = c[o2];
        final boolean ufc = uf.isConnected(i1.seek(o1), i2.seek(o2));
        assertEquals(c1 == c2, ufc);
        // always
        uf.union(i1, i2);
        if (c1 != c2) {
            for (int j = 0; j < size; j++) {
                if (c[j] == c1) {
                    c[j] = c2;
                }
            }
            --numc;
        }
        assertEquals(numc, uf.getRoots().size());
    }
}

Example 20 with DBIDArrayIter

use of de.lmu.ifi.dbs.elki.database.ids.DBIDArrayIter in project elki by elki-project.

the class WeightedQuickUnionStaticDBIDsTest method testRoots.

@Test
public void testRoots() {
    DBIDRange range = DBIDUtil.generateStaticDBIDRange(8);
    UnionFind uf = new WeightedQuickUnionStaticDBIDs(range);
    DBIDArrayIter i1 = range.iter(), i2 = range.iter();
    uf.union(i1.seek(0), i2.seek(1));
    uf.union(i1.seek(2), i2.seek(3));
    assertEquals(6, uf.getRoots().size());
    uf.union(i1.seek(0), i2.seek(2));
    assertEquals(5, uf.getRoots().size());
    uf.union(i1.seek(4), i2.seek(5));
    uf.union(i1.seek(6), i2.seek(7));
    uf.union(i1.seek(4), i2.seek(6));
    assertEquals(2, uf.getRoots().size());
    uf.union(i1.seek(0), i2.seek(4));
    assertEquals(1, uf.getRoots().size());
}