support sqrtpi function

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1900416 13f79535-47bb-0310-9956-ffa450edef68

poi/src/main/java/org/apache/poi/ss/formula/atp/AnalysisToolPak.java

@@ -172,7 +172,7 @@ public final class AnalysisToolPak implements UDFFinder {
         r(m, "RTD", null);
         r(m, "SERIESSUM", null);
         r(m, "SINGLE", Single.instance);
-        r(m, "SQRTPI", null);
+        r(m, "SQRTPI", Sqrtpi.instance);
         r(m, "SUMIFS", Sumifs.instance);
         r(m, "SWITCH", Switch.instance);
         r(m, "TBILLEQ", null);

poi/src/main/java/org/apache/poi/ss/formula/functions/Sqrtpi.java

@@ -0,0 +1,68 @@
+/* ====================================================================
+   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 org.apache.poi.ss.util.NumberToTextConverter;
+
+/**
+ * Implementation for Excel SQRTPI() function.
+ * <p>
+ *   <b>Syntax</b>:<br> <b>SQRT  </b>(<b>number</b>)<br>
+ * </p>
+ * <p>
+ *   Returns the square root of (number * pi).
+ * </p>
+ * <p>
+ *   See https://support.microsoft.com/en-us/office/sqrtpi-function-1fb4e63f-9b51-46d6-ad68-b3e7a8b519b4
+ * </p>
+ */
+public class Sqrtpi implements FreeRefFunction {
+
+    public static final Sqrtpi instance = new Sqrtpi();
+
+    @Override
+    public ValueEval evaluate(final ValueEval[] args, final OperationEvaluationContext ec) {
+        if (args.length != 1) {
+            return ErrorEval.VALUE_INVALID;
+        }
+        return evaluate(ec.getRowIndex(), ec.getColumnIndex(), args[0]);
+    }
+
+    private ValueEval evaluate(final int srcRowIndex, final int srcColumnIndex, final ValueEval arg0) {
+        try {
+            final ValueEval v1 = OperandResolver.getSingleValue(arg0, srcRowIndex, srcColumnIndex);
+            final double d = OperandResolver.coerceValueToDouble(v1);
+            if (isInvalidInput(d)) {
+                return ErrorEval.NUM_ERROR;
+            }
+            final double result = Math.sqrt(Math.PI * d);
+            return new NumberEval(Double.parseDouble(NumberToTextConverter.toText(result)));
+        } catch (EvaluationException e) {
+            return e.getErrorEval();
+        }
+    }
+
+    private boolean isInvalidInput(double d) {
+        return (d < 0);
+    }
+}

poi/src/test/java/org/apache/poi/ss/formula/functions/TestSqrtpi.java

@@ -0,0 +1,88 @@
+/* ====================================================================
+   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 java.util.Arrays;
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+/**
+ * Tests for {@link Sqrtpi}
+ */
+final class TestSqrtpi {
+
+    private static final OperationEvaluationContext ec = new OperationEvaluationContext(null, null, 0, 0, 0, null);
+
+    //https://support.microsoft.com/en-us/office/sqrtpi-function-1fb4e63f-9b51-46d6-ad68-b3e7a8b519b4
+    @Test
+    void testBasic() {
+        confirmValue(Arrays.asList(1), 1.77245385090552);
+        confirmValue(Arrays.asList(2), 2.506628274631);
+    }
+
+    @Test
+    void testNumError() {
+        confirmNumError(Arrays.asList(-1));
+    }
+
+    @Test
+    void testInvalidError() {
+        confirmInvalid(Arrays.asList());
+        confirmInvalid(Arrays.asList("num"));
+        confirmInvalid(Arrays.asList(3, "num"));
+    }
+
+    private static ValueEval invokeValue(List<Object> numberList) {
+        ValueEval[] args = new ValueEval[numberList.size()];
+        int i = 0;
+        for (Object obj : numberList) {
+            if (obj instanceof Number) {
+                args[i++] = new NumberEval(((Number)obj).doubleValue());
+            } else {
+                args[i++] = new StringEval(obj.toString());
+            }
+        }
+        return Sqrtpi.instance.evaluate(args, ec);
+    }
+
+    private static void confirmValue(List<Object> numberList, double expected) {
+        ValueEval result = invokeValue(numberList);
+        assertEquals(NumberEval.class, result.getClass());
+        assertEquals(expected, ((NumberEval) result).getNumberValue(), 0.00000000000001);
+    }
+
+    private static void confirmNumError(List<Object> numberList) {
+        ValueEval result = invokeValue(numberList);
+        assertEquals(ErrorEval.class, result.getClass());
+        assertEquals(ErrorEval.NUM_ERROR, result);
+    }
+
+    private static void confirmInvalid(List<Object> numberList) {
+        ValueEval result = invokeValue(numberList);
+        assertEquals(ErrorEval.class, result.getClass());
+        assertEquals(ErrorEval.VALUE_INVALID, result);
+    }
+}