standardize function

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1897493 13f79535-47bb-0310-9956-ffa450edef68

4 files changed, 178 insertions, 2 deletions

diff --git a/poi/src/main/java/org/apache/poi/ss/formula/eval/FunctionEval.java b/poi/src/main/java/org/apache/poi/ss/formula/eval/FunctionEval.java
index 60899ae9ed..b22ec1ef6a 100644
--- a/poi/src/main/java/org/apache/poi/ss/formula/eval/FunctionEval.java
+++ b/poi/src/main/java/org/apache/poi/ss/formula/eval/FunctionEval.java
@@ -276,7 +276,7 @@ public final class FunctionEval {
         retval[294] = NormSDist.instance;
         retval[295] = NormInv.instance;
         retval[296] = NormSInv.instance;
-        // 297: STANDARDIZE
+        retval[297] = Standardize.instance;
         retval[298] = NumericFunction.ODD;
         // 299: PERMUT
         retval[300] = NumericFunction.POISSON;
diff --git a/poi/src/main/java/org/apache/poi/ss/formula/functions/Standardize.java b/poi/src/main/java/org/apache/poi/ss/formula/functions/Standardize.java
new file mode 100644
index 0000000000..5e34ebf80c
--- /dev/null
+++ b/poi/src/main/java/org/apache/poi/ss/formula/functions/Standardize.java
@@ -0,0 +1,79 @@
+/* ====================================================================
+   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 STANDARDIZE() function.<p>
+ *
+ * https://support.microsoft.com/en-us/office/standardize-function-81d66554-2d54-40ec-ba83-6437108ee775
+ */
+public final class Standardize extends Fixed3ArgFunction implements FreeRefFunction {
+
+    public static final Standardize instance = new Standardize();
+
+    @Override
+    public ValueEval evaluate(int srcRowIndex, int srcColumnIndex, ValueEval arg1, ValueEval arg2, ValueEval arg3) {
+        try {
+            Double xval = evaluateValue(arg1, srcRowIndex, srcColumnIndex);
+            if (xval == null) {
+                return ErrorEval.VALUE_INVALID;
+            }
+            Double mean = evaluateValue(arg2, srcRowIndex, srcColumnIndex);
+            if (mean == null) {
+                return ErrorEval.VALUE_INVALID;
+            }
+            Double stdev = evaluateValue(arg3, srcRowIndex, srcColumnIndex);
+            if (stdev == null) {
+                return ErrorEval.VALUE_INVALID;
+            } else if (stdev.doubleValue() <= 0) {
+                return ErrorEval.NUM_ERROR;
+            }
+
+            BigDecimal result = new BigDecimal(xval.doubleValue() - mean.doubleValue())
+                    .divide(new BigDecimal(stdev), MathContext.DECIMAL128);
+            return new NumberEval(result.doubleValue());
+        } catch (EvaluationException e) {
+            return e.getErrorEval();
+        }
+    }
+
+    @Override
+    public ValueEval evaluate(ValueEval[] args, OperationEvaluationContext ec) {
+        if (args.length == 3) {
+            return evaluate(ec.getRowIndex(), ec.getColumnIndex(), args[0], args[1], args[2]);
+        }
+
+        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/TestNormSDist.java b/poi/src/test/java/org/apache/poi/ss/formula/functions/TestNormSDist.java
index 5fd209eba0..a5a3922b9f 100644
--- a/poi/src/test/java/org/apache/poi/ss/formula/functions/TestNormSDist.java
+++ b/poi/src/test/java/org/apache/poi/ss/formula/functions/TestNormSDist.java
@@ -23,7 +23,6 @@ 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.BoolEval;
 import org.apache.poi.ss.formula.eval.ErrorEval;
 import org.apache.poi.ss.formula.eval.NumberEval;
 import org.apache.poi.ss.formula.eval.StringEval;
diff --git a/poi/src/test/java/org/apache/poi/ss/formula/functions/TestStandardize.java b/poi/src/test/java/org/apache/poi/ss/formula/functions/TestStandardize.java
new file mode 100644
index 0000000000..9150573d5d
--- /dev/null
+++ b/poi/src/test/java/org/apache/poi/ss/formula/functions/TestStandardize.java
@@ -0,0 +1,98 @@
+/* ====================================================================
+   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.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.addRow;
+import static org.apache.poi.ss.util.Utils.assertDouble;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+/**
+ * Tests for {@link Standardize}
+ */
+final class TestStandardize {
+
+    private static final OperationEvaluationContext ec = new OperationEvaluationContext(null, null, 0, 0, 0, null);
+
+    @Test
+    void testBasic() {
+        confirmValue("42", "40", "1.5", 1.33333333);
+    }
+
+    @Test
+    void testInvalid() {
+        confirmInvalidError("A1","B2","C2");
+    }
+
+    @Test
+    void testNumError() {
+        confirmNumError("42","40","0");
+        confirmNumError("42","40","-0.1");
+    }
+
+    //https://support.microsoft.com/en-us/office/standardize-function-81d66554-2d54-40ec-ba83-6437108ee775
+    @Test
+    void testMicrosoftExample1() throws IOException {
+        try (HSSFWorkbook wb = new HSSFWorkbook()) {
+            HSSFSheet sheet = wb.createSheet();
+            addRow(sheet, 0, "Data", "Description");
+            addRow(sheet, 1, 42, "Value to normalize");
+            addRow(sheet, 2, 40, "Arithmetic mean of the distribution");
+            addRow(sheet, 3, 1.5, "Standard deviation of the distribution");
+            HSSFFormulaEvaluator fe = new HSSFFormulaEvaluator(wb);
+            HSSFCell cell = wb.getSheetAt(0).getRow(0).createCell(100);
+            assertDouble(fe, cell, "STANDARDIZE(A2,A3,A4)", 1.33333333, 0.000001);
+        }
+    }
+
+    private static ValueEval invokeValue(String number1, String number2, String number3) {
+        ValueEval[] args = new ValueEval[] { new StringEval(number1), new StringEval(number2), new StringEval(number3)};
+        return Standardize.instance.evaluate(args, ec);
+    }
+
+    private static void confirmValue(String number1, String number2, String number3, double expected) {
+        ValueEval result = invokeValue(number1, number2, number3);
+        assertEquals(NumberEval.class, result.getClass());
+        assertEquals(expected, ((NumberEval) result).getNumberValue(), 0.0000001);
+    }
+
+    private static void confirmInvalidError(String number1, String number2, String number3) {
+        ValueEval result = invokeValue(number1, number2, number3);
+        assertEquals(ErrorEval.class, result.getClass());
+        assertEquals(ErrorEval.VALUE_INVALID, result);
+    }
+
+    private static void confirmNumError(String number1, String number2, String number3) {
+        ValueEval result = invokeValue(number1, number2, number3);
+        assertEquals(ErrorEval.class, result.getClass());
+        assertEquals(ErrorEval.NUM_ERROR, result);
+    }
+
+}