01: /*
02: * Licensed to the Apache Software Foundation (ASF) under one or more
03: * contributor license agreements. See the NOTICE file distributed with
04: * this work for additional information regarding copyright ownership.
05: * The ASF licenses this file to You under the Apache License, Version 2.0
06: * (the "License"); you may not use this file except in compliance with
07: * the License. You may obtain a copy of the License at
08: *
09: * http://www.apache.org/licenses/LICENSE-2.0
10: *
11: * Unless required by applicable law or agreed to in writing, software
12: * distributed under the License is distributed on an "AS IS" BASIS,
13: * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14: * See the License for the specific language governing permissions and
15: * limitations under the License.
16: */
17: /*
18: * Created on May 6, 2005
19: *
20: */
21: package org.apache.poi.hssf.record.formula.functions;
22:
23: import org.apache.poi.hssf.record.formula.eval.BlankEval;
24: import org.apache.poi.hssf.record.formula.eval.ErrorEval;
25: import org.apache.poi.hssf.record.formula.eval.Eval;
26: import org.apache.poi.hssf.record.formula.eval.NumberEval;
27: import org.apache.poi.hssf.record.formula.eval.NumericValueEval;
28: import org.apache.poi.hssf.record.formula.eval.ValueEval;
29:
30: /**
31: * @author Amol S. Deshmukh < amolweb at ya hoo dot com >
32: *
33: */
34: public class Log10 extends NumericFunction {
35: private static final double LOG_10_TO_BASE_e = Math.log(10);
36:
37: public Eval evaluate(Eval[] operands, int srcRow, short srcCol) {
38: double d = 0;
39: ValueEval retval = null;
40:
41: switch (operands.length) {
42: default:
43: retval = ErrorEval.VALUE_INVALID;
44: break;
45: case 1:
46: ValueEval ve = singleOperandEvaluate(operands[0], srcRow,
47: srcCol);
48: if (ve instanceof NumericValueEval) {
49: NumericValueEval ne = (NumericValueEval) ve;
50: d = ne.getNumberValue();
51: } else if (ve instanceof BlankEval) {
52: // do nothing
53: } else {
54: retval = ErrorEval.NUM_ERROR;
55: }
56: }
57:
58: if (retval == null) {
59: d = Math.log(d) / LOG_10_TO_BASE_e;
60: retval = (Double.isNaN(d) || Double.isInfinite(d)) ? (ValueEval) ErrorEval.NUM_ERROR
61: : new NumberEval(d);
62: }
63: return retval;
64: }
65:
66: }
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