From e9c7ed28a6d0039279573680f730fbeb8066d061 Mon Sep 17 00:00:00 2001 From: Phil Steitz Date: Sun, 7 Mar 2004 21:55:18 +0000 Subject: [PATCH] Replaced low-accuracy textbook comparison values with values from R. git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/math/trunk@141126 13f79535-47bb-0310-9956-ffa450edef68 --- .../commons/math/stat/TestStatisticTest.java | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) diff --git a/src/test/org/apache/commons/math/stat/TestStatisticTest.java b/src/test/org/apache/commons/math/stat/TestStatisticTest.java index b3184bd58..a8914a2ac 100644 --- a/src/test/org/apache/commons/math/stat/TestStatisticTest.java +++ b/src/test/org/apache/commons/math/stat/TestStatisticTest.java @@ -23,7 +23,7 @@ import junit.framework.TestSuite; /** * Test cases for the TestStatistic class. * - * @version $Revision: 1.12 $ $Date: 2004/03/07 20:47:06 $ + * @version $Revision: 1.13 $ $Date: 2004/03/07 21:55:18 $ */ public final class TestStatisticTest extends TestCase { @@ -212,14 +212,13 @@ public final class TestStatisticTest extends TestCase { for (int i = 0; i < sample2.length; i++) { sampleStats2.addValue(sample2[i]); } - //FIXME: textbook example reported t stat uses pooled variance - // should replace the following two tests with R-verified example - assertEquals("two sample t stat", 1.634, testStatistic.t(sample1, sample2), 0.1); - assertEquals("two sample t stat", 1.634, testStatistic.t(sampleStats1, sampleStats2), 0.1); + + // Target comparison values computed using R version 1.8.1 (Linux version) + assertEquals("two sample t stat", 1.6037, testStatistic.t(sample1, sample2), 10E-4); + assertEquals("two sample t stat", 1.6037, testStatistic.t(sampleStats1, sampleStats2), 10E-4); + assertEquals("two sample p value", 0.0644, testStatistic.tTest(sample1, sample2) / 2d, 10E-4); + assertEquals("two sample p value", 0.0644, testStatistic.tTest(sampleStats1, sampleStats2) / 2d, 10E-4); - // These tests are OK, since book reports non-pooled exact p-value - assertEquals("two sample p value", 0.059, testStatistic.tTest(sample1, sample2) / 2d, 10E-3); - assertEquals("two sample p value", 0.059, testStatistic.tTest(sampleStats1, sampleStats2) / 2d, 10E-3); assertTrue("two sample t-test reject", testStatistic.tTest(sample1, sample2, 0.2)); assertTrue("two sample t-test reject", testStatistic.tTest(sampleStats1, sampleStats2, 0.2)); assertTrue("two sample t-test accept", !testStatistic.tTest(sample1, sample2, 0.1)); @@ -278,7 +277,7 @@ public final class TestStatisticTest extends TestCase { testStatistic.t(sampleStats1, tooShortStats); fail("insufficient data, IllegalArgumentException expected"); } catch (IllegalArgumentException ex) { - // exptected + // expected } } }