NormSDist.java

/* ====================================================================
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   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
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       http://www.apache.org/licenses/LICENSE-2.0

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   distributed under the License is distributed on an "AS IS" BASIS,
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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;

/**
 * Implementation for Excel NORMSDIST() and NORM.S.DIST functions.
 * <ul>
 *   <li>https://support.microsoft.com/en-us/office/normsdist-function-463369ea-0345-445d-802a-4ff0d6ce7cac</li>
 *   <li>https://support.microsoft.com/en-us/office/norm-s-dist-function-1e787282-3832-4520-a9ae-bd2a8d99ba88</li>
 * </ul>
 */
public final class NormSDist extends Fixed1ArgFunction implements FreeRefFunction {

    public static final NormSDist instance = new NormSDist();

    private NormSDist() {}

    @Override
    public ValueEval evaluate(int srcRowIndex, int srcColumnIndex, ValueEval arg1) {
        try {
            Double xval = evaluateValue(arg1, srcRowIndex, srcColumnIndex);
            if (xval == null) {
                return ErrorEval.VALUE_INVALID;
            } else if (xval < 0) {
                return ErrorEval.NUM_ERROR;
            }

            return new NumberEval(NormDist.probability(xval.doubleValue(), 0, 1, true));
        } catch (EvaluationException e) {
            return e.getErrorEval();
        }
    }

    @Override
    public ValueEval evaluate(ValueEval[] args, OperationEvaluationContext ec) {
        if (args.length == 1) {
            return evaluate(ec.getRowIndex(), ec.getColumnIndex(), args[0]);
        }

        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);
    }
}