/* * Copyright (C) 2012 The Guava Authors * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.google.common.math; import static com.google.common.math.StatsTesting.ALLOWED_ERROR; import static com.google.common.math.StatsTesting.ALL_MANY_VALUES; import static com.google.common.math.StatsTesting.EMPTY_STATS_ITERABLE; import static com.google.common.math.StatsTesting.MANY_VALUES; import static com.google.common.math.StatsTesting.MANY_VALUES_COUNT; import static com.google.common.math.StatsTesting.MANY_VALUES_STATS_ITERABLE; import static com.google.common.math.StatsTesting.MANY_VALUES_SUM_OF_PRODUCTS_OF_DELTAS; import static com.google.common.math.StatsTesting.ONE_VALUE; import static com.google.common.math.StatsTesting.ONE_VALUE_STATS; import static com.google.common.math.StatsTesting.OTHER_MANY_VALUES; import static com.google.common.math.StatsTesting.OTHER_MANY_VALUES_COUNT; import static com.google.common.math.StatsTesting.OTHER_MANY_VALUES_STATS; import static com.google.common.math.StatsTesting.OTHER_ONE_VALUE; import static com.google.common.math.StatsTesting.OTHER_ONE_VALUE_STATS; import static com.google.common.math.StatsTesting.OTHER_TWO_VALUES; import static com.google.common.math.StatsTesting.OTHER_TWO_VALUES_STATS; import static com.google.common.math.StatsTesting.TWO_VALUES; import static com.google.common.math.StatsTesting.TWO_VALUES_STATS; import static com.google.common.math.StatsTesting.TWO_VALUES_SUM_OF_PRODUCTS_OF_DELTAS; import static com.google.common.math.StatsTesting.assertDiagonalLinearTransformation; import static com.google.common.math.StatsTesting.assertHorizontalLinearTransformation; import static com.google.common.math.StatsTesting.assertLinearTransformationNaN; import static com.google.common.math.StatsTesting.assertStatsApproxEqual; import static com.google.common.math.StatsTesting.assertVerticalLinearTransformation; import static com.google.common.math.StatsTesting.createFilledPairedStatsAccumulator; import static com.google.common.math.StatsTesting.createPartitionedFilledPairedStatsAccumulator; import static com.google.common.truth.Truth.assertThat; import com.google.common.math.StatsTesting.ManyValues; import java.util.Collections; import junit.framework.TestCase; /** * Tests for {@link PairedStatsAccumulator}. This tests the stats methods for instances built with * {@link PairedStatsAccumulator#add}, and various error cases of that method. For tests of the * {@link PairedStatsAccumulator#snapshot} method which returns {@link PairedStats} instances, see * {@link PairedStatsTest}. * * @author Pete Gillin */ public class PairedStatsAccumulatorTest extends TestCase { private PairedStatsAccumulator emptyAccumulator; private PairedStatsAccumulator emptyAccumulatorByAddAllEmptyPairedStats; private PairedStatsAccumulator oneValueAccumulator; private PairedStatsAccumulator oneValueAccumulatorByAddAllEmptyPairedStats; private PairedStatsAccumulator twoValuesAccumulator; private PairedStatsAccumulator twoValuesAccumulatorByAddAllPartitionedPairedStats; private PairedStatsAccumulator manyValuesAccumulator; private PairedStatsAccumulator manyValuesAccumulatorByAddAllPartitionedPairedStats; private PairedStatsAccumulator horizontalValuesAccumulator; private PairedStatsAccumulator horizontalValuesAccumulatorByAddAllPartitionedPairedStats; private PairedStatsAccumulator verticalValuesAccumulator; private PairedStatsAccumulator verticalValuesAccumulatorByAddAllPartitionedPairedStats; private PairedStatsAccumulator constantValuesAccumulator; private PairedStatsAccumulator constantValuesAccumulatorByAddAllPartitionedPairedStats; @Override protected void setUp() throws Exception { super.setUp(); emptyAccumulator = new PairedStatsAccumulator(); emptyAccumulatorByAddAllEmptyPairedStats = new PairedStatsAccumulator(); emptyAccumulatorByAddAllEmptyPairedStats.addAll(emptyAccumulator.snapshot()); oneValueAccumulator = new PairedStatsAccumulator(); oneValueAccumulator.add(ONE_VALUE, OTHER_ONE_VALUE); oneValueAccumulatorByAddAllEmptyPairedStats = new PairedStatsAccumulator(); oneValueAccumulatorByAddAllEmptyPairedStats.add(ONE_VALUE, OTHER_ONE_VALUE); oneValueAccumulatorByAddAllEmptyPairedStats.addAll(emptyAccumulator.snapshot()); twoValuesAccumulator = createFilledPairedStatsAccumulator(TWO_VALUES, OTHER_TWO_VALUES); twoValuesAccumulatorByAddAllPartitionedPairedStats = createPartitionedFilledPairedStatsAccumulator(TWO_VALUES, OTHER_TWO_VALUES, 1); manyValuesAccumulator = createFilledPairedStatsAccumulator(MANY_VALUES, OTHER_MANY_VALUES); manyValuesAccumulatorByAddAllPartitionedPairedStats = createPartitionedFilledPairedStatsAccumulator(MANY_VALUES, OTHER_MANY_VALUES, 2); horizontalValuesAccumulator = createFilledPairedStatsAccumulator( MANY_VALUES, Collections.nCopies(MANY_VALUES_COUNT, OTHER_ONE_VALUE)); horizontalValuesAccumulatorByAddAllPartitionedPairedStats = createPartitionedFilledPairedStatsAccumulator( MANY_VALUES, Collections.nCopies(MANY_VALUES_COUNT, OTHER_ONE_VALUE), 2); verticalValuesAccumulator = createFilledPairedStatsAccumulator( Collections.nCopies(OTHER_MANY_VALUES_COUNT, ONE_VALUE), OTHER_MANY_VALUES); verticalValuesAccumulatorByAddAllPartitionedPairedStats = createPartitionedFilledPairedStatsAccumulator( Collections.nCopies(OTHER_MANY_VALUES_COUNT, ONE_VALUE), OTHER_MANY_VALUES, 2); constantValuesAccumulator = createFilledPairedStatsAccumulator( Collections.nCopies(MANY_VALUES_COUNT, ONE_VALUE), Collections.nCopies(MANY_VALUES_COUNT, OTHER_ONE_VALUE)); constantValuesAccumulatorByAddAllPartitionedPairedStats = createPartitionedFilledPairedStatsAccumulator( Collections.nCopies(MANY_VALUES_COUNT, ONE_VALUE), Collections.nCopies(MANY_VALUES_COUNT, OTHER_ONE_VALUE), 2); } public void testCount() { assertThat(emptyAccumulator.count()).isEqualTo(0); assertThat(emptyAccumulatorByAddAllEmptyPairedStats.count()).isEqualTo(0); assertThat(oneValueAccumulator.count()).isEqualTo(1); assertThat(oneValueAccumulatorByAddAllEmptyPairedStats.count()).isEqualTo(1); assertThat(twoValuesAccumulator.count()).isEqualTo(2); assertThat(twoValuesAccumulatorByAddAllPartitionedPairedStats.count()).isEqualTo(2); assertThat(manyValuesAccumulator.count()).isEqualTo(MANY_VALUES_COUNT); assertThat(manyValuesAccumulatorByAddAllPartitionedPairedStats.count()) .isEqualTo(MANY_VALUES_COUNT); } public void testCountOverflow_doesNotThrow() { PairedStatsAccumulator accumulator = new PairedStatsAccumulator(); accumulator.add(ONE_VALUE, OTHER_ONE_VALUE); for (int power = 1; power < Long.SIZE - 1; power++) { accumulator.addAll(accumulator.snapshot()); } // Should overflow without throwing. accumulator.addAll(accumulator.snapshot()); assertThat(accumulator.count()).isLessThan(0L); } public void testXStats() { assertStatsApproxEqual(EMPTY_STATS_ITERABLE, emptyAccumulator.xStats()); assertStatsApproxEqual(EMPTY_STATS_ITERABLE, emptyAccumulatorByAddAllEmptyPairedStats.xStats()); assertStatsApproxEqual(ONE_VALUE_STATS, oneValueAccumulator.xStats()); assertStatsApproxEqual(ONE_VALUE_STATS, oneValueAccumulatorByAddAllEmptyPairedStats.xStats()); assertStatsApproxEqual(TWO_VALUES_STATS, twoValuesAccumulator.xStats()); assertStatsApproxEqual( TWO_VALUES_STATS, twoValuesAccumulatorByAddAllPartitionedPairedStats.xStats()); assertStatsApproxEqual(MANY_VALUES_STATS_ITERABLE, manyValuesAccumulator.xStats()); assertStatsApproxEqual( MANY_VALUES_STATS_ITERABLE, manyValuesAccumulatorByAddAllPartitionedPairedStats.xStats()); } public void testYStats() { assertStatsApproxEqual(EMPTY_STATS_ITERABLE, emptyAccumulator.yStats()); assertStatsApproxEqual(EMPTY_STATS_ITERABLE, emptyAccumulatorByAddAllEmptyPairedStats.yStats()); assertStatsApproxEqual(OTHER_ONE_VALUE_STATS, oneValueAccumulator.yStats()); assertStatsApproxEqual( OTHER_ONE_VALUE_STATS, oneValueAccumulatorByAddAllEmptyPairedStats.yStats()); assertStatsApproxEqual(OTHER_TWO_VALUES_STATS, twoValuesAccumulator.yStats()); assertStatsApproxEqual( OTHER_TWO_VALUES_STATS, twoValuesAccumulatorByAddAllPartitionedPairedStats.yStats()); assertStatsApproxEqual(OTHER_MANY_VALUES_STATS, manyValuesAccumulator.yStats()); assertStatsApproxEqual( OTHER_MANY_VALUES_STATS, manyValuesAccumulatorByAddAllPartitionedPairedStats.yStats()); } public void testPopulationCovariance() { try { emptyAccumulator.populationCovariance(); fail("Expected IllegalStateException"); } catch (IllegalStateException expected) { } try { emptyAccumulatorByAddAllEmptyPairedStats.populationCovariance(); fail("Expected IllegalStateException"); } catch (IllegalStateException expected) { } assertThat(oneValueAccumulator.populationCovariance()).isWithin(0.0).of(0.0); assertThat(oneValueAccumulatorByAddAllEmptyPairedStats.populationCovariance()) .isWithin(0.0) .of(0.0); assertThat(twoValuesAccumulator.populationCovariance()) .isWithin(ALLOWED_ERROR) .of(TWO_VALUES_SUM_OF_PRODUCTS_OF_DELTAS / 2); assertThat(twoValuesAccumulatorByAddAllPartitionedPairedStats.populationCovariance()) .isWithin(ALLOWED_ERROR) .of(TWO_VALUES_SUM_OF_PRODUCTS_OF_DELTAS / 2); assertThat(manyValuesAccumulator.populationCovariance()) .isWithin(ALLOWED_ERROR) .of(MANY_VALUES_SUM_OF_PRODUCTS_OF_DELTAS / MANY_VALUES_COUNT); assertThat(manyValuesAccumulatorByAddAllPartitionedPairedStats.populationCovariance()) .isWithin(ALLOWED_ERROR) .of(MANY_VALUES_SUM_OF_PRODUCTS_OF_DELTAS / MANY_VALUES_COUNT); // For datasets of many double values, we test many combinations of finite and non-finite // x-values: for (ManyValues values : ALL_MANY_VALUES) { PairedStatsAccumulator accumulator = createFilledPairedStatsAccumulator(values.asIterable(), OTHER_MANY_VALUES); PairedStatsAccumulator accumulatorByAddAllPartitionedPairedStats = createPartitionedFilledPairedStatsAccumulator(values.asIterable(), OTHER_MANY_VALUES, 2); double populationCovariance = accumulator.populationCovariance(); double populationCovarianceByAddAllPartitionedPairedStats = accumulatorByAddAllPartitionedPairedStats.populationCovariance(); if (values.hasAnyNonFinite()) { assertThat(populationCovariance).named("population covariance of " + values).isNaN(); assertThat(populationCovarianceByAddAllPartitionedPairedStats) .named("population covariance by addAll(PairedStats) of " + values) .isNaN(); } else { assertThat(populationCovariance) .named("population covariance of " + values) .isWithin(ALLOWED_ERROR) .of(MANY_VALUES_SUM_OF_PRODUCTS_OF_DELTAS / MANY_VALUES_COUNT); assertThat(populationCovarianceByAddAllPartitionedPairedStats) .named("population covariance by addAll(PairedStats) of " + values) .isWithin(ALLOWED_ERROR) .of(MANY_VALUES_SUM_OF_PRODUCTS_OF_DELTAS / MANY_VALUES_COUNT); } } assertThat(horizontalValuesAccumulator.populationCovariance()).isWithin(ALLOWED_ERROR).of(0.0); assertThat(horizontalValuesAccumulatorByAddAllPartitionedPairedStats.populationCovariance()) .isWithin(ALLOWED_ERROR) .of(0.0); assertThat(verticalValuesAccumulator.populationCovariance()).isWithin(ALLOWED_ERROR).of(0.0); assertThat(verticalValuesAccumulatorByAddAllPartitionedPairedStats.populationCovariance()) .isWithin(ALLOWED_ERROR) .of(0.0); assertThat(constantValuesAccumulator.populationCovariance()).isWithin(ALLOWED_ERROR).of(0.0); assertThat(constantValuesAccumulatorByAddAllPartitionedPairedStats.populationCovariance()) .isWithin(ALLOWED_ERROR) .of(0.0); } public void testSampleCovariance() { try { emptyAccumulator.sampleCovariance(); fail("Expected IllegalStateException"); } catch (IllegalStateException expected) { } try { emptyAccumulatorByAddAllEmptyPairedStats.sampleCovariance(); fail("Expected IllegalStateException"); } catch (IllegalStateException expected) { } try { oneValueAccumulator.sampleCovariance(); fail("Expected IllegalStateException"); } catch (IllegalStateException expected) { } try { oneValueAccumulatorByAddAllEmptyPairedStats.sampleCovariance(); fail("Expected IllegalStateException"); } catch (IllegalStateException expected) { } assertThat(twoValuesAccumulator.sampleCovariance()) .isWithin(ALLOWED_ERROR) .of(TWO_VALUES_SUM_OF_PRODUCTS_OF_DELTAS); assertThat(twoValuesAccumulatorByAddAllPartitionedPairedStats.sampleCovariance()) .isWithin(ALLOWED_ERROR) .of(TWO_VALUES_SUM_OF_PRODUCTS_OF_DELTAS); assertThat(manyValuesAccumulator.sampleCovariance()) .isWithin(ALLOWED_ERROR) .of(MANY_VALUES_SUM_OF_PRODUCTS_OF_DELTAS / (MANY_VALUES_COUNT - 1)); assertThat(manyValuesAccumulatorByAddAllPartitionedPairedStats.sampleCovariance()) .isWithin(ALLOWED_ERROR) .of(MANY_VALUES_SUM_OF_PRODUCTS_OF_DELTAS / (MANY_VALUES_COUNT - 1)); assertThat(horizontalValuesAccumulator.sampleCovariance()).isWithin(ALLOWED_ERROR).of(0.0); assertThat(horizontalValuesAccumulatorByAddAllPartitionedPairedStats.sampleCovariance()) .isWithin(ALLOWED_ERROR) .of(0.0); assertThat(verticalValuesAccumulator.sampleCovariance()).isWithin(ALLOWED_ERROR).of(0.0); assertThat(verticalValuesAccumulatorByAddAllPartitionedPairedStats.sampleCovariance()) .isWithin(ALLOWED_ERROR) .of(0.0); assertThat(constantValuesAccumulator.sampleCovariance()).isWithin(ALLOWED_ERROR).of(0.0); assertThat(constantValuesAccumulatorByAddAllPartitionedPairedStats.sampleCovariance()) .isWithin(ALLOWED_ERROR) .of(0.0); } public void testPearsonsCorrelationCoefficient() { try { emptyAccumulator.pearsonsCorrelationCoefficient(); fail("Expected IllegalStateException"); } catch (IllegalStateException expected) { } try { emptyAccumulatorByAddAllEmptyPairedStats.pearsonsCorrelationCoefficient(); fail("Expected IllegalStateException"); } catch (IllegalStateException expected) { } try { oneValueAccumulator.pearsonsCorrelationCoefficient(); fail("Expected IllegalStateException"); } catch (IllegalStateException expected) { } try { oneValueAccumulatorByAddAllEmptyPairedStats.pearsonsCorrelationCoefficient(); fail("Expected IllegalStateException"); } catch (IllegalStateException expected) { } assertThat(twoValuesAccumulator.pearsonsCorrelationCoefficient()) .isWithin(ALLOWED_ERROR) .of( twoValuesAccumulator.populationCovariance() / (twoValuesAccumulator.xStats().populationStandardDeviation() * twoValuesAccumulator.yStats().populationStandardDeviation())); assertThat(manyValuesAccumulator.pearsonsCorrelationCoefficient()) .isWithin(ALLOWED_ERROR) .of( manyValuesAccumulator.populationCovariance() / (manyValuesAccumulator.xStats().populationStandardDeviation() * manyValuesAccumulator.yStats().populationStandardDeviation())); assertThat(manyValuesAccumulatorByAddAllPartitionedPairedStats.pearsonsCorrelationCoefficient()) .isWithin(ALLOWED_ERROR) .of( manyValuesAccumulatorByAddAllPartitionedPairedStats.populationCovariance() / (manyValuesAccumulatorByAddAllPartitionedPairedStats .xStats() .populationStandardDeviation() * manyValuesAccumulatorByAddAllPartitionedPairedStats .yStats() .populationStandardDeviation())); // For datasets of many double values, we test many combinations of finite and non-finite // y-values: for (ManyValues values : ALL_MANY_VALUES) { PairedStatsAccumulator accumulator = createFilledPairedStatsAccumulator(MANY_VALUES, values.asIterable()); PairedStatsAccumulator accumulatorByAddAllPartitionedPairedStats = createPartitionedFilledPairedStatsAccumulator(MANY_VALUES, values.asIterable(), 2); double pearsonsCorrelationCoefficient = accumulator.pearsonsCorrelationCoefficient(); double pearsonsCorrelationCoefficientByAddAllPartitionedPairedStats = accumulatorByAddAllPartitionedPairedStats.pearsonsCorrelationCoefficient(); if (values.hasAnyNonFinite()) { assertThat(pearsonsCorrelationCoefficient) .named("Pearson's correlation coefficient of " + values) .isNaN(); assertThat(pearsonsCorrelationCoefficient) .named("Pearson's correlation coefficient by addAll(PairedStats) of " + values) .isNaN(); } else { assertThat(pearsonsCorrelationCoefficient) .named("Pearson's correlation coefficient of " + values) .isWithin(ALLOWED_ERROR) .of( accumulator.populationCovariance() / (accumulator.xStats().populationStandardDeviation() * accumulator.yStats().populationStandardDeviation())); assertThat(pearsonsCorrelationCoefficientByAddAllPartitionedPairedStats) .named("Pearson's correlation coefficient by addAll(PairedStats) of " + values) .isWithin(ALLOWED_ERROR) .of( accumulatorByAddAllPartitionedPairedStats.populationCovariance() / (accumulatorByAddAllPartitionedPairedStats .xStats() .populationStandardDeviation() * accumulatorByAddAllPartitionedPairedStats .yStats() .populationStandardDeviation())); } } try { horizontalValuesAccumulator.pearsonsCorrelationCoefficient(); fail("Expected IllegalStateException"); } catch (IllegalStateException expected) { } try { horizontalValuesAccumulatorByAddAllPartitionedPairedStats.pearsonsCorrelationCoefficient(); fail("Expected IllegalStateException"); } catch (IllegalStateException expected) { } try { verticalValuesAccumulator.pearsonsCorrelationCoefficient(); fail("Expected IllegalStateException"); } catch (IllegalStateException expected) { } try { verticalValuesAccumulatorByAddAllPartitionedPairedStats.pearsonsCorrelationCoefficient(); fail("Expected IllegalStateException"); } catch (IllegalStateException expected) { } try { constantValuesAccumulator.pearsonsCorrelationCoefficient(); fail("Expected IllegalStateException"); } catch (IllegalStateException expected) { } try { constantValuesAccumulatorByAddAllPartitionedPairedStats.pearsonsCorrelationCoefficient(); fail("Expected IllegalStateException"); } catch (IllegalStateException expected) { } } public void testLeastSquaresFit() { try { emptyAccumulator.leastSquaresFit(); fail("Expected IllegalStateException"); } catch (IllegalStateException expected) { } try { emptyAccumulatorByAddAllEmptyPairedStats.leastSquaresFit(); fail("Expected IllegalStateException"); } catch (IllegalStateException expected) { } try { oneValueAccumulator.leastSquaresFit(); fail("Expected IllegalStateException"); } catch (IllegalStateException expected) { } try { oneValueAccumulatorByAddAllEmptyPairedStats.leastSquaresFit(); fail("Expected IllegalStateException"); } catch (IllegalStateException expected) { } assertDiagonalLinearTransformation( twoValuesAccumulator.leastSquaresFit(), twoValuesAccumulator.xStats().mean(), twoValuesAccumulator.yStats().mean(), twoValuesAccumulator.xStats().populationVariance(), twoValuesAccumulator.populationCovariance()); assertDiagonalLinearTransformation( twoValuesAccumulatorByAddAllPartitionedPairedStats.leastSquaresFit(), twoValuesAccumulatorByAddAllPartitionedPairedStats.xStats().mean(), twoValuesAccumulatorByAddAllPartitionedPairedStats.yStats().mean(), twoValuesAccumulatorByAddAllPartitionedPairedStats.xStats().populationVariance(), twoValuesAccumulatorByAddAllPartitionedPairedStats.populationCovariance()); assertDiagonalLinearTransformation( manyValuesAccumulator.leastSquaresFit(), manyValuesAccumulator.xStats().mean(), manyValuesAccumulator.yStats().mean(), manyValuesAccumulator.xStats().populationVariance(), manyValuesAccumulator.populationCovariance()); assertDiagonalLinearTransformation( manyValuesAccumulatorByAddAllPartitionedPairedStats.leastSquaresFit(), manyValuesAccumulatorByAddAllPartitionedPairedStats.xStats().mean(), manyValuesAccumulatorByAddAllPartitionedPairedStats.yStats().mean(), manyValuesAccumulatorByAddAllPartitionedPairedStats.xStats().populationVariance(), manyValuesAccumulatorByAddAllPartitionedPairedStats.populationCovariance()); // For datasets of many double values, we test many combinations of finite and non-finite // x-values: for (ManyValues values : ALL_MANY_VALUES) { PairedStatsAccumulator accumulator = createFilledPairedStatsAccumulator(values.asIterable(), OTHER_MANY_VALUES); PairedStatsAccumulator accumulatorByAddAllPartitionedPairedStats = createPartitionedFilledPairedStatsAccumulator(values.asIterable(), OTHER_MANY_VALUES, 2); LinearTransformation fit = accumulator.leastSquaresFit(); LinearTransformation fitByAddAllPartitionedPairedStats = accumulatorByAddAllPartitionedPairedStats.leastSquaresFit(); if (values.hasAnyNonFinite()) { assertLinearTransformationNaN(fit); assertLinearTransformationNaN(fitByAddAllPartitionedPairedStats); } else { assertDiagonalLinearTransformation( fit, accumulator.xStats().mean(), accumulator.yStats().mean(), accumulator.xStats().populationVariance(), accumulator.populationCovariance()); assertDiagonalLinearTransformation( fitByAddAllPartitionedPairedStats, accumulatorByAddAllPartitionedPairedStats.xStats().mean(), accumulatorByAddAllPartitionedPairedStats.yStats().mean(), accumulatorByAddAllPartitionedPairedStats.xStats().populationVariance(), accumulatorByAddAllPartitionedPairedStats.populationCovariance()); } } assertHorizontalLinearTransformation( horizontalValuesAccumulator.leastSquaresFit(), horizontalValuesAccumulator.yStats().mean()); assertHorizontalLinearTransformation( horizontalValuesAccumulatorByAddAllPartitionedPairedStats.leastSquaresFit(), horizontalValuesAccumulatorByAddAllPartitionedPairedStats.yStats().mean()); assertVerticalLinearTransformation( verticalValuesAccumulator.leastSquaresFit(), verticalValuesAccumulator.xStats().mean()); assertVerticalLinearTransformation( verticalValuesAccumulatorByAddAllPartitionedPairedStats.leastSquaresFit(), verticalValuesAccumulatorByAddAllPartitionedPairedStats.xStats().mean()); try { constantValuesAccumulator.leastSquaresFit(); fail("Expected IllegalStateException"); } catch (IllegalStateException expected) { } try { constantValuesAccumulatorByAddAllPartitionedPairedStats.leastSquaresFit(); fail("Expected IllegalStateException"); } catch (IllegalStateException expected) { } } }