add besselj function

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1897764 13f79535-47bb-0310-9956-ffa450edef68

3 files changed, 170 insertions, 1 deletions

diff --git a/poi/src/main/java/org/apache/poi/ss/formula/atp/AnalysisToolPak.java b/poi/src/main/java/org/apache/poi/ss/formula/atp/AnalysisToolPak.java
index bbd3e8987e..5dcb5720dd 100644
--- a/poi/src/main/java/org/apache/poi/ss/formula/atp/AnalysisToolPak.java
+++ b/poi/src/main/java/org/apache/poi/ss/formula/atp/AnalysisToolPak.java
@@ -72,7 +72,7 @@ public final class AnalysisToolPak implements UDFFinder {
         r(m, "AVERAGEIFS", Averageifs.instance);
         r(m, "BAHTTEXT", null);
         r(m, "BESSELI", null);
-        r(m, "BESSELJ", null);
+        r(m, "BESSELJ", BesselJ.instance);
         r(m, "BESSELK", null);
         r(m, "BESSELY", null);
         r(m, "BIN2DEC", Bin2Dec.instance);
diff --git a/poi/src/main/java/org/apache/poi/ss/formula/functions/BesselJ.java b/poi/src/main/java/org/apache/poi/ss/formula/functions/BesselJ.java
new file mode 100644
index 0000000000..74b12db2f8
--- /dev/null
+++ b/poi/src/main/java/org/apache/poi/ss/formula/functions/BesselJ.java
@@ -0,0 +1,77 @@
+/* ====================================================================
+   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.EvaluationException;
+import org.apache.poi.ss.formula.eval.NumberEval;
+import org.apache.poi.ss.formula.eval.OperandResolver;
+import org.apache.poi.ss.formula.eval.ValueEval;
+
+import java.math.BigDecimal;
+import java.math.MathContext;
+
+/**
+ * Implementation for Excel BESSELJ() function.
+ * <p>
+ * https://support.microsoft.com/en-us/office/besselj-function-839cb181-48de-408b-9d80-bd02982d94f7
+ */
+public final class BesselJ extends Fixed2ArgFunction implements FreeRefFunction {
+
+    public static final FreeRefFunction instance = new BesselJ();
+
+    @Override
+    public ValueEval evaluate(int srcRowIndex, int srcColumnIndex, ValueEval arg1, ValueEval arg2) {
+        try {
+            Double xval = evaluateValue(arg1, srcRowIndex, srcColumnIndex);
+            if (xval == null) {
+                return ErrorEval.VALUE_INVALID;
+            }
+            Double orderDouble = evaluateValue(arg2, srcRowIndex, srcColumnIndex);
+            if (orderDouble == null) {
+                return ErrorEval.VALUE_INVALID;
+            }
+            int order = orderDouble.intValue();
+            if (order < 0) {
+                return ErrorEval.NUM_ERROR;
+            }
+
+            org.apache.commons.math3.special.BesselJ bes = new org.apache.commons.math3.special.BesselJ(order);
+
+            return new NumberEval(bes.value(xval));
+        } catch (EvaluationException e) {
+            return e.getErrorEval();
+        }
+    }
+
+    @Override
+    public ValueEval evaluate(ValueEval[] args, OperationEvaluationContext ec) {
+         if (args.length == 2) {
+            return evaluate(ec.getRowIndex(), ec.getColumnIndex(), args[0], args[1]);
+        }
+
+        return ErrorEval.VALUE_INVALID;
+    }
+
+    private static Double evaluateValue(ValueEval arg, int srcRowIndex, int srcColumnIndex) throws EvaluationException {
+        ValueEval veText = OperandResolver.getSingleValue(arg, srcRowIndex, srcColumnIndex);
+        String strText1 = OperandResolver.coerceValueToString(veText);
+        return OperandResolver.parseDouble(strText1);
+    }
+}
\ No newline at end of file
diff --git a/poi/src/test/java/org/apache/poi/ss/formula/functions/TestBesselJ.java b/poi/src/test/java/org/apache/poi/ss/formula/functions/TestBesselJ.java
new file mode 100644
index 0000000000..e3420503a8
--- /dev/null
+++ b/poi/src/test/java/org/apache/poi/ss/formula/functions/TestBesselJ.java
@@ -0,0 +1,92 @@
+/* ====================================================================
+   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.hssf.usermodel.HSSFCell;
+import org.apache.poi.hssf.usermodel.HSSFFormulaEvaluator;
+import org.apache.poi.hssf.usermodel.HSSFRow;
+import org.apache.poi.hssf.usermodel.HSSFSheet;
+import org.apache.poi.hssf.usermodel.HSSFWorkbook;
+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 java.io.IOException;
+
+import static org.apache.poi.ss.util.Utils.assertDouble;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+/**
+ * Tests for {@link BesselJ}
+ */
+final class TestBesselJ {
+
+    private static final OperationEvaluationContext ec = new OperationEvaluationContext(null, null, 0, 0, 0, null);
+
+    @Test
+    void testInvalid() {
+        confirmInvalidError("A1","B2");
+    }
+
+    @Test
+    void testNumError() {
+        confirmNumError("22.5","-40");
+    }
+
+    //https://support.microsoft.com/en-us/office/besselj-function-839cb181-48de-408b-9d80-bd02982d94f7
+    @Test
+    void testMicrosoftExample1() throws IOException {
+        try (HSSFWorkbook wb = new HSSFWorkbook()) {
+            HSSFSheet sheet = wb.createSheet();
+            HSSFRow row = sheet.createRow(0);
+            HSSFFormulaEvaluator fe = new HSSFFormulaEvaluator(wb);
+            HSSFCell cell = row.createCell(0);
+            //this tolerance is too high but commons-math3 and excel don't match up as closely as we'd like
+            double tolerance = 0.000001;
+            assertDouble(fe, cell, "BESSELJ(1.9, 2)", 0.329925829, tolerance);
+            assertDouble(fe, cell, "BESSELJ(1.9, 2.5)", 0.329925829, tolerance);
+        }
+    }
+
+    private static ValueEval invokeValue(String number1, String number2) {
+        ValueEval[] args = new ValueEval[] { new StringEval(number1), new StringEval(number2) };
+        return BesselJ.instance.evaluate(args, ec);
+    }
+
+    private static void confirmValue(String number1, String number2, double expected) {
+        ValueEval result = invokeValue(number1, number2);
+        assertEquals(NumberEval.class, result.getClass());
+        assertEquals(expected, ((NumberEval) result).getNumberValue(), 0.00000000000001);
+    }
+
+    private static void confirmInvalidError(String number1, String number2) {
+        ValueEval result = invokeValue(number1, number2);
+        assertEquals(ErrorEval.class, result.getClass());
+        assertEquals(ErrorEval.VALUE_INVALID, result);
+    }
+
+    private static void confirmNumError(String number1, String number2) {
+        ValueEval result = invokeValue(number1, number2);
+        assertEquals(ErrorEval.class, result.getClass());
+        assertEquals(ErrorEval.NUM_ERROR, result);
+    }
+
+}