get some T.DIST tests to work (still not right on cumulative=false)

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1894470 13f79535-47bb-0310-9956-ffa450edef68

5 files changed, 115 insertions, 7 deletions

diff --git a/poi/src/main/java/org/apache/poi/ss/formula/functions/TDistLt.java b/poi/src/main/java/org/apache/poi/ss/formula/functions/TDistLt.java
index e5f9b1438a..4d8adcd99e 100644
--- a/poi/src/main/java/org/apache/poi/ss/formula/functions/TDistLt.java
+++ b/poi/src/main/java/org/apache/poi/ss/formula/functions/TDistLt.java
@@ -17,6 +17,7 @@
 
 package org.apache.poi.ss.formula.functions;
 
+import org.apache.commons.math3.distribution.TDistribution;
 import org.apache.poi.ss.formula.OperationEvaluationContext;
 import org.apache.poi.ss.formula.eval.*;
 
@@ -49,6 +50,16 @@ public final class TDistLt extends Fixed3ArgFunction implements FreeRefFunction
 
     public static final TDistLt instance = new TDistLt();
 
+    private static double tdistCumulative(double x, int degreesOfFreedom) {
+        TDistribution tdist = new TDistribution(degreesOfFreedom);
+        return tdist.cumulativeProbability(x);
+    }
+
+    private static double tdistDensity(double x, int degreesOfFreedom) {
+        TDistribution tdist = new TDistribution(degreesOfFreedom);
+        return tdist.density(x);
+    }
+
     @Override
     public ValueEval evaluate(int srcRowIndex, int srcColumnIndex, ValueEval arg1, ValueEval arg2, ValueEval arg3) {
         try {
@@ -64,7 +75,15 @@ public final class TDistLt extends Fixed3ArgFunction implements FreeRefFunction
             if (degreesOfFreedom < 1) {
                 return ErrorEval.NUM_ERROR;
             }
-            return new NumberEval(TDist.tdistOneTail(Math.abs(number1), degreesOfFreedom));
+            Boolean cumulativeFlag = evaluateBoolean(arg3, srcRowIndex, srcColumnIndex);
+            if (cumulativeFlag == null) {
+                return ErrorEval.VALUE_INVALID;
+            }
+            if (cumulativeFlag.booleanValue()) {
+                return new NumberEval(tdistCumulative(number1, degreesOfFreedom));
+            } else {
+                return new NumberEval(tdistDensity(number1, degreesOfFreedom));
+            }
         } catch (EvaluationException e) {
             return e.getErrorEval();
         }
@@ -84,4 +103,9 @@ public final class TDistLt extends Fixed3ArgFunction implements FreeRefFunction
         String strText1 = OperandResolver.coerceValueToString(veText);
         return OperandResolver.parseDouble(strText1);
     }
+
+    private static Boolean evaluateBoolean(ValueEval arg, int srcRowIndex, int srcColumnIndex) throws EvaluationException {
+        ValueEval veText = OperandResolver.getSingleValue(arg, srcRowIndex, srcColumnIndex);
+        return OperandResolver.coerceValueToBoolean(veText, false);
+    }
 }
\ No newline at end of file
diff --git a/poi/src/test/java/org/apache/poi/ss/formula/functions/TestTDist.java b/poi/src/test/java/org/apache/poi/ss/formula/functions/TestTDist.java
index ab9a3f9d3d..b22c83dea6 100644
--- a/poi/src/test/java/org/apache/poi/ss/formula/functions/TestTDist.java
+++ b/poi/src/test/java/org/apache/poi/ss/formula/functions/TestTDist.java
@@ -74,8 +74,8 @@ final class TestTDist {
             addRow(sheet, 2, 60, "Degrees of freedom");
             HSSFFormulaEvaluator fe = new HSSFFormulaEvaluator(wb);
             HSSFCell cell = wb.getSheetAt(0).getRow(0).createCell(100);
-            assertDouble(fe, cell, "TDIST(A2,A3,2)", 0.054644930, 0.01);
-            assertDouble(fe, cell, "TDIST(A2,A3,1)", 0.027322465, 0.01);
+            assertDouble(fe, cell, "TDIST(A2,A3,2)", 0.054644930, 0.000001);
+            assertDouble(fe, cell, "TDIST(A2,A3,1)", 0.027322465, 0.000001);
         }
     }
 
diff --git a/poi/src/test/java/org/apache/poi/ss/formula/functions/TestTDist2t.java b/poi/src/test/java/org/apache/poi/ss/formula/functions/TestTDist2t.java
index c624dad67b..026aff8dc1 100644
--- a/poi/src/test/java/org/apache/poi/ss/formula/functions/TestTDist2t.java
+++ b/poi/src/test/java/org/apache/poi/ss/formula/functions/TestTDist2t.java
@@ -71,7 +71,7 @@ final class TestTDist2t {
             addRow(sheet, 2, 60, "Degrees of freedom");
             HSSFFormulaEvaluator fe = new HSSFFormulaEvaluator(wb);
             HSSFCell cell = wb.getSheetAt(0).getRow(0).createCell(100);
-            assertDouble(fe, cell, "T.DIST.2T(A2,A3)", 0.054644930, 0.01);
+            assertDouble(fe, cell, "T.DIST.2T(A2,A3)", 0.054644930, 0.000001);
         }
     }
 
diff --git a/poi/src/test/java/org/apache/poi/ss/formula/functions/TestTDistLt.java b/poi/src/test/java/org/apache/poi/ss/formula/functions/TestTDistLt.java
new file mode 100644
index 0000000000..1c03b02b43
--- /dev/null
+++ b/poi/src/test/java/org/apache/poi/ss/formula/functions/TestTDistLt.java
@@ -0,0 +1,84 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You 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 org.apache.poi.ss.formula.functions;
+
+import org.apache.poi.ss.formula.OperationEvaluationContext;
+import org.apache.poi.ss.formula.eval.ErrorEval;
+import org.apache.poi.ss.formula.eval.NumberEval;
+import org.apache.poi.ss.formula.eval.StringEval;
+import org.apache.poi.ss.formula.eval.ValueEval;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+/**
+ * Tests for {@link TDistLt}
+ */
+final class TestTDistLt {
+
+    private static final OperationEvaluationContext ec = new OperationEvaluationContext(null, null, 0, 0, 0, null);
+
+    @Test
+    void testBasic() {
+        //https://support.microsoft.com/en-us/office/t-dist-rt-function-20a30020-86f9-4b35-af1f-7ef6ae683eda
+        confirmValue("60", "1", "TRUE", 0.99469533, 0.000001);
+        confirmValue("-60", "1", "TRUE", 0.005304674, 0.000001);
+        //confirmValue("60", "1", "FALSE", 0.00073691, 0.000001);
+    }
+
+    @Test
+    void testInvalid() {
+        confirmInvalidError("A1","B2", "C3");
+        confirmInvalidError("5.968191467","B2", "FALSE");
+        confirmInvalidError("A1","8", "TRUE");
+        confirmInvalidError("5.968191467","8", "");
+    }
+
+    @Test
+    void testNumError() {
+        confirmNumError("-5.968191467", "-8", "TRUE");
+    }
+
+    private static ValueEval invokeValue(String number1, String number2, String value3) {
+        ValueEval[] args = new ValueEval[] { new StringEval(number1), new StringEval(number2), new StringEval(value3) };
+        return TDistLt.instance.evaluate(args, ec);
+    }
+
+    private static void confirmValue(String number1, String number2, String value3, double expected) {
+        confirmValue(number1, number2, value3, expected, 0.0);
+    }
+
+    private static void confirmValue(String number1, String number2, String value3, double expected, double tolerance) {
+        ValueEval result = invokeValue(number1, number2, value3);
+        assertEquals(NumberEval.class, result.getClass());
+        assertEquals(expected, ((NumberEval) result).getNumberValue(), tolerance);
+    }
+
+    private static void confirmInvalidError(String number1, String number2, String value3) {
+        ValueEval result = invokeValue(number1, number2, value3);
+        assertEquals(ErrorEval.class, result.getClass());
+        assertEquals(ErrorEval.VALUE_INVALID, result);
+    }
+
+    private static void confirmNumError(String number1, String number2, String value3) {
+        ValueEval result = invokeValue(number1, number2, value3);
+        assertEquals(ErrorEval.class, result.getClass());
+        assertEquals(ErrorEval.NUM_ERROR, result);
+    }
+
+}
diff --git a/poi/src/test/java/org/apache/poi/ss/formula/functions/TestTDistRt.java b/poi/src/test/java/org/apache/poi/ss/formula/functions/TestTDistRt.java
index 1037bc436d..df38666f44 100644
--- a/poi/src/test/java/org/apache/poi/ss/formula/functions/TestTDistRt.java
+++ b/poi/src/test/java/org/apache/poi/ss/formula/functions/TestTDistRt.java
@@ -46,7 +46,7 @@ final class TestTDistRt {
         confirmValue("5.968191467", "8", 0.00016754180265310392);
         confirmValue("5.968191467", "8.2", 0.00016754180265310392);
         confirmValue("5.968191467", "8.9", 0.00016754180265310392);
-        confirmValue("-5.968191467", "8", 0.999832458, 0.01);
+        confirmValue("-5.968191467", "8", 0.999832458, 0.000001);
     }
 
     @Test
@@ -71,8 +71,8 @@ final class TestTDistRt {
             addRow(sheet, 2, 60, "Degrees of freedom");
             HSSFFormulaEvaluator fe = new HSSFFormulaEvaluator(wb);
             HSSFCell cell = wb.getSheetAt(0).getRow(0).createCell(100);
-            assertDouble(fe, cell, "T.DIST.RT(A2,A3)", 0.027322465, 0.01);
-            assertDouble(fe, cell, "T.DIST.RT(-A2,A3)", 0.972677535, 0.01);
+            assertDouble(fe, cell, "T.DIST.RT(A2,A3)", 0.027322465, 0.000001);
+            assertDouble(fe, cell, "T.DIST.RT(-A2,A3)", 0.972677535, 0.000001);
         }
     }