* {@link PairedStatsAccumulator#snapshot} method which returns {@link PairedStats} instances, see
 * {@link PairedStatsTest}.
 *
 * @author Pete Gillin
 */
@NullUnmarked
public class PairedStatsAccumulatorTest extends TestCase {

  private PairedStatsAccumulator emptyAccumulator;
  private PairedStatsAccumulator emptyAccumulatorByAddAllEmptyPairedStats;

/**
 * A mutable object which accumulates paired double values (e.g. points on a plane) and tracks some
 * basic statistics over all the values added so far. This class is not thread safe.
 *
 * @author Pete Gillin
 * @since 20.0
 */
@J2ktIncompatible
@GwtIncompatible
public final class PairedStatsAccumulator {
  /** Creates a new accumulator. */
  public PairedStatsAccumulator() {}

/**
 * An immutable value object capturing some basic statistics about a collection of paired double
 * values (e.g. points on a plane). Build instances with {@link PairedStatsAccumulator#snapshot}.
 *
 * @author Pete Gillin
 * @since 20.0
 */
@J2ktIncompatible
@GwtIncompatible
public final class PairedStats implements Serializable {

  private final Stats xStats;
  private final Stats yStats;

import java.util.Random;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Tests for {@link Quantiles}.
 *
 * @author Pete Gillin
 */
@NullUnmarked
public class QuantilesTest extends TestCase {

  /*
   * Since Quantiles provides a fluent-style API, each test covers a chain of methods resulting in

import java.util.Random;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Tests for {@link Quantiles}.
 *
 * @author Pete Gillin
 */
@NullUnmarked
public class QuantilesTest extends TestCase {

  /*
   * Since Quantiles provides a fluent-style API, each test covers a chain of methods resulting in

import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Tests for {@link PairedStats}. This tests instances created by {@link
 * PairedStatsAccumulator#snapshot}.
 *
 * @author Pete Gillin
 */
@NullUnmarked
public class PairedStatsTest extends TestCase {

  public void testCount() {
    assertThat(EMPTY_PAIRED_STATS.count()).isEqualTo(0);
    assertThat(ONE_VALUE_PAIRED_STATS.count()).isEqualTo(1);

import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Tests for {@link PairedStats}. This tests instances created by {@link
 * PairedStatsAccumulator#snapshot}.
 *
 * @author Pete Gillin
 */
@NullUnmarked
public class PairedStatsTest extends TestCase {

  public void testCount() {
    assertThat(EMPTY_PAIRED_STATS.count()).isEqualTo(0);
    assertThat(ONE_VALUE_PAIRED_STATS.count()).isEqualTo(1);

 * {@link PairedStatsAccumulator#snapshot} method which returns {@link PairedStats} instances, see
 * {@link PairedStatsTest}.
 *
 * @author Pete Gillin
 */
@NullUnmarked
public class PairedStatsAccumulatorTest extends TestCase {

  private PairedStatsAccumulator emptyAccumulator;
  private PairedStatsAccumulator emptyAccumulatorByAddAllEmptyPairedStats;

/**
 * Inputs, expected outputs, and helper methods for tests of {@link StatsAccumulator}, {@link
 * Stats}, {@link PairedStatsAccumulator}, and {@link PairedStats}.
 *
 * @author Pete Gillin
 */
@NullUnmarked
class StatsTesting {
  // TODO(cpovirk): Convince myself that this larger error makes sense.
  static final double ALLOWED_ERROR = isAndroid() ? .25 : 1e-10;

  // Inputs and their statistics:

/**
 * A mutable object which accumulates double values and tracks some basic statistics over all the
 * values added so far. The values may be added singly or in groups. This class is not thread safe.
 *
 * @author Pete Gillin
 * @author Kevin Bourrillion
 * @since 20.0
 */
@J2ktIncompatible
@GwtIncompatible
public final class StatsAccumulator {
  /** Creates a new accumulator. */
  public StatsAccumulator() {}