@Test
public void testRowPercents() throws Exception {

  Table bush = Table.read().csv("../data/bush.csv");
  bush.addColumns(bush.dateColumn("date").year());
  Table xtab = CrossTab.rowPercents(bush, "who", "date year");
  assertEquals(1.0, xtab.doubleColumn(xtab.columnCount() - 1).getDouble(0), 0.00001);
}