--- /dev/null
+/* ====================================================================\r
+ Licensed to the Apache Software Foundation (ASF) under one or more\r
+ contributor license agreements. See the NOTICE file distributed with\r
+ this work for additional information regarding copyright ownership.\r
+ The ASF licenses this file to You under the Apache License, Version 2.0\r
+ (the "License"); you may not use this file except in compliance with\r
+ the License. You may obtain a copy of the License at\r
+\r
+ http://www.apache.org/licenses/LICENSE-2.0\r
+\r
+ Unless required by applicable law or agreed to in writing, software\r
+ distributed under the License is distributed on an "AS IS" BASIS,\r
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\r
+ See the License for the specific language governing permissions and\r
+ limitations under the License.\r
+==================================================================== */\r
+\r
+package org.apache.poi.ss.formula.functions;\r
+\r
+import org.apache.poi.ss.formula.eval.*;\r
+\r
+import java.math.BigDecimal;\r
+\r
+/**\r
+ * Implementation for Excel DELTA() function.<p/>\r
+ * <p/>\r
+ * <b>Syntax</b>:<br/> <b>DELTA </b>(<b>number1</b>,<b>number2</b> )<br/>\r
+ * <p/>\r
+ * Tests whether two values are equal. Returns 1 if number1 = number2; returns 0 otherwise.\r
+ * Use this function to filter a set of values. For example, by summing several DELTA functions\r
+ * you calculate the count of equal pairs. This function is also known as the Kronecker Delta function.\r
+ *\r
+ * <ul>\r
+ * <li>If number1 is nonnumeric, DELTA returns the #VALUE! error value.</li>\r
+ * <li>If number2 is nonnumeric, DELTA returns the #VALUE! error value.</li>\r
+ * </ul>\r
+ *\r
+ * @author cedric dot walter @ gmail dot com\r
+ */\r
+public final class Delta extends Fixed2ArgFunction {\r
+\r
+ private final static NumberEval ONE = new NumberEval(1);\r
+ private final static NumberEval ZERO = new NumberEval(0);\r
+\r
+ @Override\r
+ public ValueEval evaluate(int srcRowIndex, int srcColumnIndex, ValueEval arg1, ValueEval arg2) {\r
+ ValueEval veText1;\r
+ try {\r
+ veText1 = OperandResolver.getSingleValue(arg1, srcRowIndex, srcColumnIndex);\r
+ } catch (EvaluationException e) {\r
+ return e.getErrorEval();\r
+ }\r
+ String strText1 = OperandResolver.coerceValueToString(veText1);\r
+ Double number1 = OperandResolver.parseDouble(strText1);\r
+ if (number1 == null) {\r
+ return ErrorEval.VALUE_INVALID;\r
+ }\r
+\r
+ ValueEval veText2;\r
+ try {\r
+ veText2 = OperandResolver.getSingleValue(arg2, srcRowIndex, srcColumnIndex);\r
+ } catch (EvaluationException e) {\r
+ return e.getErrorEval();\r
+ }\r
+\r
+ String strText2 = OperandResolver.coerceValueToString(veText2);\r
+ Double number2 = OperandResolver.parseDouble(strText2);\r
+ if (number2 == null) {\r
+ return ErrorEval.VALUE_INVALID;\r
+ }\r
+\r
+ int result = new BigDecimal(number1.doubleValue()).compareTo(new BigDecimal(number2.doubleValue()));\r
+ return result == 0 ? ONE : ZERO;\r
+ }\r
+\r
+}
\ No newline at end of file
--- /dev/null
+/* ====================================================================
+ 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 junit.framework.TestCase;
+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;
+
+/**
+ * Tests for {@link org.apache.poi.ss.formula.functions.Delta}
+ *
+ * @author cedric dot walter @ gmail dot com
+ */
+public final class TestDelta extends TestCase {
+
+ private static ValueEval invokeValue(String number1, String number2) {
+ ValueEval[] args = new ValueEval[] { new StringEval(number1), new StringEval(number2), };
+ return new Delta().evaluate(args, -1, -1);
+ }
+
+ 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(), 0.0);
+ }
+
+ private static void confirmValueError(String number1, String number2) {
+ ValueEval result = invokeValue(number1, number2);
+ assertEquals(ErrorEval.class, result.getClass());
+ assertEquals(ErrorEval.VALUE_INVALID, result);
+ }
+
+ public void testBasic() {
+ confirmValue("5","4", 0); // Checks whether 5 equals 4 (0)
+ confirmValue("5","5", 1); // Checks whether 5 equals 5 (1)
+
+ confirmValue("0.5","0", 0); // Checks whether 0.5 equals 0 (0)
+ confirmValue("0.50","0.5", 1);
+ confirmValue("0.5000000000","0.5", 1);
+ }
+
+ public void testErrors() {
+ confirmValueError("A1","B2");
+ confirmValueError("AAAA","BBBB");
+ }
+}
projects / poi.git / commitdiff