TestNormDist.java

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   this work for additional information regarding copyright ownership.
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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.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;
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 NormDist}
 */
final class TestNormDist {

    private static final OperationEvaluationContext ec = new OperationEvaluationContext(null, null, 0, 0, 0, null);

    @Test
    void testBasic() {
        confirmValue("42", "40", "1.5", true, 0.908788780274132);
        confirmValue("42", "40", "1.5", false, 0.109340049783996);
    }

    @Test
    void testInvalid() {
        confirmInvalidError("A1","B2","C2", false);
    }

    @Test
    void testNumError() {
        confirmNumError("42","40","0", false);
        confirmNumError("42","40","0", true);
        confirmNumError("42","40","-0.1", false);
        confirmNumError("42","40","-0.1", true);
    }

    //https://support.microsoft.com/en-us/office/normdist-function-126db625-c53e-4591-9a22-c9ff422d6d58
    //https://support.microsoft.com/en-us/office/norm-dist-function-edb1cc14-a21c-4e53-839d-8082074c9f8d
    @Test
    void testMicrosoftExample1() throws IOException {
        try (HSSFWorkbook wb = new HSSFWorkbook()) {
            HSSFSheet sheet = wb.createSheet();
            addRow(sheet, 0, "Data", "Description");
            addRow(sheet, 1, 42, "Value for which you want the distribution");
            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, "NORMDIST(A2,A3,A4,TRUE)", 0.908788780274132, 0.00000000000001);
            assertDouble(fe, cell, "NORM.DIST(A2,A3,A4,TRUE)", 0.908788780274132, 0.00000000000001);
        }
    }

    private static ValueEval invokeValue(String number1, String number2, String number3, boolean cumulative) {
        ValueEval[] args = new ValueEval[] { new StringEval(number1), new StringEval(number2), new StringEval(number3), BoolEval.valueOf(cumulative)};
        return NormDist.instance.evaluate(args, ec);
    }

    private static void confirmValue(String number1, String number2, String number3, boolean cumulative, double expected) {
        ValueEval result = invokeValue(number1, number2, number3, cumulative);
        assertEquals(NumberEval.class, result.getClass());
        assertEquals(expected, ((NumberEval) result).getNumberValue(), 0.00000000000001);
    }

    private static void confirmInvalidError(String number1, String number2, String number3, boolean cumulative) {
        ValueEval result = invokeValue(number1, number2, number3, cumulative);
        assertEquals(ErrorEval.class, result.getClass());
        assertEquals(ErrorEval.VALUE_INVALID, result);
    }

    private static void confirmNumError(String number1, String number2, String number3, boolean cumulative) {
        ValueEval result = invokeValue(number1, number2, number3, cumulative);
        assertEquals(ErrorEval.class, result.getClass());
        assertEquals(ErrorEval.NUM_ERROR, result);
    }

}